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2025, vol. 32, no. 2, pp.
233-255.
https://doi.org/10.1007/s12613-024-2925-5
Abstract:
The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources. Oxygen, crucial for supporting human life on the Moon, can be extracted from lunar regolith, which is highly rich in oxygen and contains polymetallic oxides. This oxygen and metal extraction can be achieved using existing metallurgical techniques. Furthermore, the ample reserves of water ice on the Moon offer another means for oxygen production. This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon, drawing from an analysis of lunar resources and environmental conditions. It delves into the principles, processes, advantages, and drawbacks of water-ice electrolysis, two-step oxygen production from lunar regolith, and one-step oxygen production from lunar regolith. The two-step methods involve hydrogen reduction, carbothermal reduction, and hydrometallurgy, while the one-step methods encompass fluorination/chlorination, high-temperature decomposition, molten salt electrolysis, and molten regolith electrolysis (MOE). Following a thorough comparison of raw materials, equipment, technology, and economic viability, MOE is identified as the most promising approach for future in-situ oxygen production on the Moon. Considering the corrosion characteristics of molten lunar regolith at high temperatures, along with the Moon’s low-gravity environment, the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon. This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.
The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources. Oxygen, crucial for supporting human life on the Moon, can be extracted from lunar regolith, which is highly rich in oxygen and contains polymetallic oxides. This oxygen and metal extraction can be achieved using existing metallurgical techniques. Furthermore, the ample reserves of water ice on the Moon offer another means for oxygen production. This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon, drawing from an analysis of lunar resources and environmental conditions. It delves into the principles, processes, advantages, and drawbacks of water-ice electrolysis, two-step oxygen production from lunar regolith, and one-step oxygen production from lunar regolith. The two-step methods involve hydrogen reduction, carbothermal reduction, and hydrometallurgy, while the one-step methods encompass fluorination/chlorination, high-temperature decomposition, molten salt electrolysis, and molten regolith electrolysis (MOE). Following a thorough comparison of raw materials, equipment, technology, and economic viability, MOE is identified as the most promising approach for future in-situ oxygen production on the Moon. Considering the corrosion characteristics of molten lunar regolith at high temperatures, along with the Moon’s low-gravity environment, the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon. This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.
2025, vol. 32, no. 2, pp.
256-269.
https://doi.org/10.1007/s12613-024-2994-5
Abstract:
Martensite is an important microstructure in ultrahigh-strength steels, and enhancing the strength of martensitic steels often involves the introduction of precipitated phases within the martensitic matrix. Despite considerable research efforts devoted to this area, a systematic summary of these advancements is lacking. This review focuses on the precipitates prevalent in ultrahigh-strength martensitic steel, primarily carbides (e.g., MC, M2C, and M3C) and intermetallic compounds (e.g., NiAl, Ni3X, and Fe2Mo). The precipitation-strengthening effect of these precipitates on ultrahigh-strength martensitic steel is discussed from the aspects of heat treatment processes, microstructure of precipitate-strengthened martensite matrix, and mechanical performance. Finally, a perspective on the development of precipitation-strengthened martensitic steel is presented to contribute to the advancement of ultrahigh-strength martensitic steel. This review highlights significant findings, ongoing challenges, and opportunities in the development of ultrahigh-strength martensitic steel.
Martensite is an important microstructure in ultrahigh-strength steels, and enhancing the strength of martensitic steels often involves the introduction of precipitated phases within the martensitic matrix. Despite considerable research efforts devoted to this area, a systematic summary of these advancements is lacking. This review focuses on the precipitates prevalent in ultrahigh-strength martensitic steel, primarily carbides (e.g., MC, M2C, and M3C) and intermetallic compounds (e.g., NiAl, Ni3X, and Fe2Mo). The precipitation-strengthening effect of these precipitates on ultrahigh-strength martensitic steel is discussed from the aspects of heat treatment processes, microstructure of precipitate-strengthened martensite matrix, and mechanical performance. Finally, a perspective on the development of precipitation-strengthened martensitic steel is presented to contribute to the advancement of ultrahigh-strength martensitic steel. This review highlights significant findings, ongoing challenges, and opportunities in the development of ultrahigh-strength martensitic steel.
2025, vol. 32, no. 2, pp.
270-291.
https://doi.org/10.1007/s12613-024-2996-3
Abstract:
Lithium metal batteries (LMBs) are emerging as a promising energy storage solution owing to their high energy density and specific capacity. However, the non-uniform plating of lithium and the potential rupture of the solid–electrolyte interphase (SEI) during extended cycling use may result in dendrite growth, which can penetrate the separator and pose significant short-circuit risks. Forming a stable SEI is essential for the long-term operation of the batteries. Fluorine-rich SEI has garnered significant attention for its ability to effectively passivate electrodes, regulate lithium deposition, and inhibit electrolyte corrosion. Understanding the structural components and preparation methods of existing fluorinated SEI is crucial for optimizing lithium metal anode performance. This paper reviews the research on optimizing LiF passivation interfaces to protect lithium metal anodes. It focuses on four types of compositions in fluorinated SEI that work synergistically to enhance SEI performance. For instance, combining compounds with LiF can further enhance the mechanical strength and ionic conductivity of the SEI. Integrating metals with LiF significantly improves electrochemical performance at the SEI/anode interface, with a necessary focus on reducing electron tunneling risks. Additionally, incorporating polymers with LiF offers balanced improvements in interfacial toughness and ionic conductivity, though maintaining structural stability over long cycles remains a critical area for future research. Although alloys combined with LiF increase surface energy and lithium affinity, challenges such as dendrite growth and volume expansion persist. In summary, this paper emphasizes the crucial role of interfacial structures in LMBs and offers comprehensive guidance for future design and development efforts in battery technology.
Lithium metal batteries (LMBs) are emerging as a promising energy storage solution owing to their high energy density and specific capacity. However, the non-uniform plating of lithium and the potential rupture of the solid–electrolyte interphase (SEI) during extended cycling use may result in dendrite growth, which can penetrate the separator and pose significant short-circuit risks. Forming a stable SEI is essential for the long-term operation of the batteries. Fluorine-rich SEI has garnered significant attention for its ability to effectively passivate electrodes, regulate lithium deposition, and inhibit electrolyte corrosion. Understanding the structural components and preparation methods of existing fluorinated SEI is crucial for optimizing lithium metal anode performance. This paper reviews the research on optimizing LiF passivation interfaces to protect lithium metal anodes. It focuses on four types of compositions in fluorinated SEI that work synergistically to enhance SEI performance. For instance, combining compounds with LiF can further enhance the mechanical strength and ionic conductivity of the SEI. Integrating metals with LiF significantly improves electrochemical performance at the SEI/anode interface, with a necessary focus on reducing electron tunneling risks. Additionally, incorporating polymers with LiF offers balanced improvements in interfacial toughness and ionic conductivity, though maintaining structural stability over long cycles remains a critical area for future research. Although alloys combined with LiF increase surface energy and lithium affinity, challenges such as dendrite growth and volume expansion persist. In summary, this paper emphasizes the crucial role of interfacial structures in LMBs and offers comprehensive guidance for future design and development efforts in battery technology.
2025, vol. 32, no. 2, pp.
292-310.
https://doi.org/10.1007/s12613-024-2966-9
Abstract:
Calcium ferrite (CF) is recognized as a potential green and efficient functional material because of its advantages of magnetism, electrochemistry, catalysis, and biocompatibility in the fields of materials chemistry, environmental engineering, and biomedicine. Therefore, the obtained research results need to be systematically summarized, and new perspectives on CF and its composite materials need to be analyzed. Based on the presented studies of CF and its composite materials, the types and structures of the crystal are summarized. In addition, the current application technologies and theoretical mechanisms with various properties in different fields are elucidated. Moreover, the various preparation methods of CF and its composite materials are elaborated in detail. Most importantly, the advantages and disadvantages of the synthesis methods of CF and its composite materials are discussed, and the existing problems and emerging challenges in practical production are identified. Furthermore, the key future research directions of CF and its composite materials have been prospected from the potential application technologies to provide references for its synthesis and efficient utilization.
Calcium ferrite (CF) is recognized as a potential green and efficient functional material because of its advantages of magnetism, electrochemistry, catalysis, and biocompatibility in the fields of materials chemistry, environmental engineering, and biomedicine. Therefore, the obtained research results need to be systematically summarized, and new perspectives on CF and its composite materials need to be analyzed. Based on the presented studies of CF and its composite materials, the types and structures of the crystal are summarized. In addition, the current application technologies and theoretical mechanisms with various properties in different fields are elucidated. Moreover, the various preparation methods of CF and its composite materials are elaborated in detail. Most importantly, the advantages and disadvantages of the synthesis methods of CF and its composite materials are discussed, and the existing problems and emerging challenges in practical production are identified. Furthermore, the key future research directions of CF and its composite materials have been prospected from the potential application technologies to provide references for its synthesis and efficient utilization.
2025, vol. 32, no. 2, pp.
311-324.
https://doi.org/10.1007/s12613-024-3014-5
Abstract:
The mechanical behavior of cemented gangue backfill materials (CGBMs) is closely related to particle size distribution (PSD) of aggregates and properties of cementitious materials. Consequently, the true triaxial compression tests, CT scanning, SEM, and EDS tests were conducted on cemented gangue backfill samples (CGBSs) with various carbon nanotube concentrations (PCNT) that satisfied fractal theory for the PSD of aggregates. The mechanical properties, energy dissipations, and failure mechanisms of the CGBSs under true triaxial compression were systematically analyzed. The results indicate that appropriate carbon nanotubes (CNTs) effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging, and the optimal effect appears at PCNT of 0.08wt%. Taking PSD fractal dimension (D) of 2.500 as an example, compared to that of CGBS without CNT, the peak strength (\begin{document}$ {\sigma _{\text{p}}} $\end{document} \begin{document}$ \varepsilon_{\text{1,p}} $\end{document} \begin{document}$ {U_{\text{e}}} $\end{document} \begin{document}$ {U_{\text{d}}} $\end{document} \begin{document}$ {\sigma _{\text{p}}} $\end{document} \begin{document}$ \varepsilon_{\text{1,p}} $\end{document} \begin{document}$ \Delta {\varepsilon _{\text{v}}} $\end{document} \begin{document}$ {\sigma _{\text{p}}} $\end{document} \begin{document}$ {U_{\text{d}}} $\end{document} \begin{document}$ \varepsilon_{\text{1,p}} $\end{document} \begin{document}$ \Delta {\varepsilon _{\text{v}}} $\end{document} \begin{document}$ \varepsilon_{\text{1,p}} $\end{document} \begin{document}$ \Delta {\varepsilon _{\text{v}}} $\end{document}
The mechanical behavior of cemented gangue backfill materials (CGBMs) is closely related to particle size distribution (PSD) of aggregates and properties of cementitious materials. Consequently, the true triaxial compression tests, CT scanning, SEM, and EDS tests were conducted on cemented gangue backfill samples (CGBSs) with various carbon nanotube concentrations (PCNT) that satisfied fractal theory for the PSD of aggregates. The mechanical properties, energy dissipations, and failure mechanisms of the CGBSs under true triaxial compression were systematically analyzed. The results indicate that appropriate carbon nanotubes (CNTs) effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging, and the optimal effect appears at PCNT of 0.08wt%. Taking PSD fractal dimension (D) of 2.500 as an example, compared to that of CGBS without CNT, the peak strength (
2025, vol. 32, no. 2, pp.
325-334.
https://doi.org/10.1007/s12613-024-2941-5
Abstract:
This study primarily investigates the rock fracture mechanism of bottom cushion layer blasting and explores the effects of the bottom cushion layer on rock fragmentation. It involves analyses of the evolution patterns of blasting stress, characteristics of crack distribution, and rock fracture features in the specimens. First, blasting model experiments were carried out using the dynamic caustics principle to investigate the influence of bottom cushion layers and initiation methods on the integrity of the bottom rock mass. The experimental results indicate that the combined use of bottom cushion layers and inverse initiation effectively protects the integrity of the bottom rock mass. Subsequently, the process of stress wave propagation and dynamic crack propagation in rocks was simulated using the continuum–discontinuum element method (CDEM) and the Landau explosion source model, with varying thicknesses of bottom cushion layers. The numerical simulation results indicate that with increasing cushion thickness, the absorption of energy generated by the explosion becomes more pronounced, resulting in fewer cracks in the bottom rock mass. This illustrates the positive role of the cushion layer in protecting the integrity of the bottom rock mass.
This study primarily investigates the rock fracture mechanism of bottom cushion layer blasting and explores the effects of the bottom cushion layer on rock fragmentation. It involves analyses of the evolution patterns of blasting stress, characteristics of crack distribution, and rock fracture features in the specimens. First, blasting model experiments were carried out using the dynamic caustics principle to investigate the influence of bottom cushion layers and initiation methods on the integrity of the bottom rock mass. The experimental results indicate that the combined use of bottom cushion layers and inverse initiation effectively protects the integrity of the bottom rock mass. Subsequently, the process of stress wave propagation and dynamic crack propagation in rocks was simulated using the continuum–discontinuum element method (CDEM) and the Landau explosion source model, with varying thicknesses of bottom cushion layers. The numerical simulation results indicate that with increasing cushion thickness, the absorption of energy generated by the explosion becomes more pronounced, resulting in fewer cracks in the bottom rock mass. This illustrates the positive role of the cushion layer in protecting the integrity of the bottom rock mass.
2025, vol. 32, no. 2, pp.
335-345.
https://doi.org/10.1007/s12613-024-2936-2
Abstract:
The depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth insight. Therefore, the depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory (DFT) calculations. The X-ray photoelectric spectroscopy (XPS) results, DFT calculation results, and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface, suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption mechanisms. First, the oxygen content in the surface of sphalerite treated with sulfite ions increased, which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and galena. Then, sulfite ions were chelated with lead ions to form PbSO3 in solution. The hydrophilic PbSO3 was more easily adsorbed on sphalerite than galena. The interaction between sulfite ions and lead ions could effectively inhibit the activation of sphalerite. In addition, the UV spectrum showed that after adding sulfite ions, the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution, indicating that xanthate interacted more readily with sulfite ions and oxygen molecules within the sphalerite system, leading to the formation of perxanthate. However, sulfite ions hardly depressed the flotation of galena and could promote the flotation of galena to some extent. This study deepened the understanding of the depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite.
The depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth insight. Therefore, the depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory (DFT) calculations. The X-ray photoelectric spectroscopy (XPS) results, DFT calculation results, and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface, suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption mechanisms. First, the oxygen content in the surface of sphalerite treated with sulfite ions increased, which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and galena. Then, sulfite ions were chelated with lead ions to form PbSO3 in solution. The hydrophilic PbSO3 was more easily adsorbed on sphalerite than galena. The interaction between sulfite ions and lead ions could effectively inhibit the activation of sphalerite. In addition, the UV spectrum showed that after adding sulfite ions, the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution, indicating that xanthate interacted more readily with sulfite ions and oxygen molecules within the sphalerite system, leading to the formation of perxanthate. However, sulfite ions hardly depressed the flotation of galena and could promote the flotation of galena to some extent. This study deepened the understanding of the depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite.
2025, vol. 32, no. 2, pp.
346-359.
https://doi.org/10.1007/s12613-024-2955-z
Abstract:
Sinter is the core raw material for blast furnaces. Flue pressure, which is an important state parameter, affects sinter quality. In this paper, flue pressure prediction and optimization were studied based on the shapley additive explanation (SHAP) to predict the flue pressure and take targeted adjustment measures. First, the sintering process data were collected and processed. A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP + extremely randomized trees (ET). The prediction accuracy of the model within the error range of ±0.25 kPa was 92.63%. SHAP analysis was employed to improve the interpretability of the prediction model. The effects of various sintering operation parameters on flue pressure, the relationship between the numerical range of key operation parameters and flue pressure, the effect of operation parameter combinations on flue pressure, and the prediction process of the flue pressure prediction model on a single sample were analyzed. A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions. The operating parameter combination was then pushed. The flue pressure was increased by 5.87% during the verification process, achieving a good optimization effect.
Sinter is the core raw material for blast furnaces. Flue pressure, which is an important state parameter, affects sinter quality. In this paper, flue pressure prediction and optimization were studied based on the shapley additive explanation (SHAP) to predict the flue pressure and take targeted adjustment measures. First, the sintering process data were collected and processed. A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP + extremely randomized trees (ET). The prediction accuracy of the model within the error range of ±0.25 kPa was 92.63%. SHAP analysis was employed to improve the interpretability of the prediction model. The effects of various sintering operation parameters on flue pressure, the relationship between the numerical range of key operation parameters and flue pressure, the effect of operation parameter combinations on flue pressure, and the prediction process of the flue pressure prediction model on a single sample were analyzed. A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions. The operating parameter combination was then pushed. The flue pressure was increased by 5.87% during the verification process, achieving a good optimization effect.
2025, vol. 32, no. 2, pp.
360-368.
https://doi.org/10.1007/s12613-024-2914-8
Abstract:
The influence of Nb–V microalloying on the hot deformation behavior and microstructures of medium Mn steel (MMS) was investigated by uniaxial hot compression tests. By establishing the constitutive equations for simulating the measured flow curves, we successfully constructed deformation activation energy (Q) maps and processing maps for identifying the region of flow instability. We concluded the following consequences of Nb–V alloying for MMS. (i) The critical strain increases and the increment diminishes with the increasing deformation temperature, suggesting that NbC precipitates more efficiently retard dynamic recrystallization (DRX) in MMS compared with solute Nb. (ii) The deformation activation energy of MMS is significantly increased and even higher than that of some reported high Mn steels, suggesting that its ability to retard DRX is greater than that of the high Mn content. (iii) The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress, in which fine recrystallized and coarse unrecrystallized grains are present.
The influence of Nb–V microalloying on the hot deformation behavior and microstructures of medium Mn steel (MMS) was investigated by uniaxial hot compression tests. By establishing the constitutive equations for simulating the measured flow curves, we successfully constructed deformation activation energy (Q) maps and processing maps for identifying the region of flow instability. We concluded the following consequences of Nb–V alloying for MMS. (i) The critical strain increases and the increment diminishes with the increasing deformation temperature, suggesting that NbC precipitates more efficiently retard dynamic recrystallization (DRX) in MMS compared with solute Nb. (ii) The deformation activation energy of MMS is significantly increased and even higher than that of some reported high Mn steels, suggesting that its ability to retard DRX is greater than that of the high Mn content. (iii) The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress, in which fine recrystallized and coarse unrecrystallized grains are present.
2025, vol. 32, no. 2, pp.
369-379.
https://doi.org/10.1007/s12613-024-2963-z
Abstract:
The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel (Fe–0.10C–5Mn) was investigated during uniaxial tensile testing. In-situ observations under scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms. These findings were discussed with the local strain measurements via digital image correlation. The results indicated that Lüders band formation in the steel was limited to 1.5% strain, which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite (RA), which led to localized stress concentrations and strain hardening and further retardation of yielding. The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin–Le Chatelier effect. The volume fraction of RA gradually decreased from 26.8% to 8.2% prior to fracture. In the late deformation stage, fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.
The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel (Fe–0.10C–5Mn) was investigated during uniaxial tensile testing. In-situ observations under scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms. These findings were discussed with the local strain measurements via digital image correlation. The results indicated that Lüders band formation in the steel was limited to 1.5% strain, which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite (RA), which led to localized stress concentrations and strain hardening and further retardation of yielding. The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin–Le Chatelier effect. The volume fraction of RA gradually decreased from 26.8% to 8.2% prior to fracture. In the late deformation stage, fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.
2025, vol. 32, no. 2, pp.
380-390.
https://doi.org/10.1007/s12613-024-2935-3
Abstract:
This work reveals the significant effects of cobalt (Co) on the microstructure and impact toughness of as-quenched high-strength steels by experimental characterizations and thermo-kinetic analyses. The results show that the Co-bearing steel exhibits finer blocks and a lower ductile–brittle transition temperature than the steel without Co. Moreover, the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to 0.6. The improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant pair. Furthermore, the addition of Co induces a larger transformation driving force and a lower bainite start temperature (BS), thereby contributing to the refinement of blocks and the increase of the V1/V2 variant pair. These findings would be instructive for the composition, microstructure design, and property optimization of high-strength steels.
This work reveals the significant effects of cobalt (Co) on the microstructure and impact toughness of as-quenched high-strength steels by experimental characterizations and thermo-kinetic analyses. The results show that the Co-bearing steel exhibits finer blocks and a lower ductile–brittle transition temperature than the steel without Co. Moreover, the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to 0.6. The improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant pair. Furthermore, the addition of Co induces a larger transformation driving force and a lower bainite start temperature (BS), thereby contributing to the refinement of blocks and the increase of the V1/V2 variant pair. These findings would be instructive for the composition, microstructure design, and property optimization of high-strength steels.
2025, vol. 32, no. 2, pp.
391-401.
https://doi.org/10.1007/s12613-024-2937-1
Abstract:
Carbon can change the phase components of low-density steels and influence the mechanical properties. In this study, a new method to control the carbon content and avoid the formation of δ-ferrite by decarburization treatment was proposed. The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined. Crussard–Jaoul (C–J) analysis was employed to examine the work hardening characteristics during the tensile test. During decarburization by heat treatments, the carbon content within the austenite phase decreased, while Mn and Al were almost unchanged; this made the steel with full austenite transform into the austenite and ferrite dual phase. Meanwhile, (Ti,V)C carbides existed in both matrix phase and the mole fraction almost the same. In addition, the formation of other carbides restrained. Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution. For the steel with the single austinite, the deformation mode of austenite was the dislocation planar glide, resulting in the formation of microbands. For the dual-phase steel, the deformation occurred by the dislocation planar glide of austenite first, with the increase in strain, the cross slip of ferrite took place, forming dislocation cells in ferrite. At the late stage of deformation, the work hardening of austinite increased rapidly, while that of ferrite increased slightly.
Carbon can change the phase components of low-density steels and influence the mechanical properties. In this study, a new method to control the carbon content and avoid the formation of δ-ferrite by decarburization treatment was proposed. The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined. Crussard–Jaoul (C–J) analysis was employed to examine the work hardening characteristics during the tensile test. During decarburization by heat treatments, the carbon content within the austenite phase decreased, while Mn and Al were almost unchanged; this made the steel with full austenite transform into the austenite and ferrite dual phase. Meanwhile, (Ti,V)C carbides existed in both matrix phase and the mole fraction almost the same. In addition, the formation of other carbides restrained. Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution. For the steel with the single austinite, the deformation mode of austenite was the dislocation planar glide, resulting in the formation of microbands. For the dual-phase steel, the deformation occurred by the dislocation planar glide of austenite first, with the increase in strain, the cross slip of ferrite took place, forming dislocation cells in ferrite. At the late stage of deformation, the work hardening of austinite increased rapidly, while that of ferrite increased slightly.
Effect of lamellarization on the microstructure and mechanical properties of marine 10Ni5CrMoV steel
2025, vol. 32, no. 2, pp.
402-413.
https://doi.org/10.1007/s12613-024-2897-5
Abstract:
Multistage heat treatment involving quenching (Q), lamellarizing (L), and tempering (T) is applied to marine 10Ni5CrMoV steel. The microstructure and mechanical properties were studied by multiscale characterizations, and the kinetics of reverse austenite transformation, strain hardening behavior, and toughening mechanism were further investigated. The lamellarized specimens possess low yield strength but high toughness, especially cryogenic toughness. Lamellarization leads to the development of film-like reversed austenite at the martensite block and lath boundaries, refining the martensite structure and lowering the equivalent grain size. Kinetic analysis of austenite reversion based on the JMAK model shows that the isothermal transformation is dominated by the growth of reversed austenite, and the maximum transformation of reversed austenite is reached at the peak temperature (750°C). The strain hardening behavior based on the modified Crussard–Jaoul analysis indicates that the reversed austenite obtained from lamellarization reduces the proportion of martensite, significantly hindering crack propagation via martensitic transformation during the deformation. As a consequence, the QLT specimens exhibit high machinability and low yield strength. Compared with the QT specimen, the ductile–brittle transition temperature of the QLT specimens decreases from −116 to −130°C due to the low equivalent grain size and reversed austenite, which increases the cleavage force required for crack propagation and absorbs the energy of external load, respectively. This work provides an idea to improve the cryogenic toughness of marine 10Ni5CrMoV steel and lays a theoretical foundation for its industrial application and comprehensive performance improvement.
Multistage heat treatment involving quenching (Q), lamellarizing (L), and tempering (T) is applied to marine 10Ni5CrMoV steel. The microstructure and mechanical properties were studied by multiscale characterizations, and the kinetics of reverse austenite transformation, strain hardening behavior, and toughening mechanism were further investigated. The lamellarized specimens possess low yield strength but high toughness, especially cryogenic toughness. Lamellarization leads to the development of film-like reversed austenite at the martensite block and lath boundaries, refining the martensite structure and lowering the equivalent grain size. Kinetic analysis of austenite reversion based on the JMAK model shows that the isothermal transformation is dominated by the growth of reversed austenite, and the maximum transformation of reversed austenite is reached at the peak temperature (750°C). The strain hardening behavior based on the modified Crussard–Jaoul analysis indicates that the reversed austenite obtained from lamellarization reduces the proportion of martensite, significantly hindering crack propagation via martensitic transformation during the deformation. As a consequence, the QLT specimens exhibit high machinability and low yield strength. Compared with the QT specimen, the ductile–brittle transition temperature of the QLT specimens decreases from −116 to −130°C due to the low equivalent grain size and reversed austenite, which increases the cleavage force required for crack propagation and absorbs the energy of external load, respectively. This work provides an idea to improve the cryogenic toughness of marine 10Ni5CrMoV steel and lays a theoretical foundation for its industrial application and comprehensive performance improvement.
2025, vol. 32, no. 2, pp.
414-424.
https://doi.org/10.1007/s12613-024-3006-5
Abstract:
Ti–6Al–4Zr–2Sn–6Mo alloy is one of the most recent titanium alloys processed using powder bed fusion–laser beam (PBF–LB) technology. This alloy has the potential to replace Ti–6Al–4V in automotive and aerospace applications, given its superior mechanical properties, which are approximately 10% higher in terms of ultimate tensile strength (UTS) and yield strength after appropriate heat treatment. In as-built conditions, the alloy is characterized by the presence of soft orthorhombic α″ martensite, necessitating a postprocessing heat treatment to decompose this phase and enhance the mechanical properties of the alloy. Usually, PBFed Ti6246 components undergo an annealing process that transforms the α″ martensite into an α–β lamellar microstructure. The primary objective of this research was to develop a solution treatment and aging (STA) heat treatment tailored to the unique microstructure produced by the additive manufacturing process to achieve an ultrafine bilamellar microstructure reinforced by precipitation hardening. This study investigated the effects of various solution temperatures in the α–β field (ranging from 800 to 875°C), cooling media (air and water), and aging time to determine the optimal heat treatment parameters for achieving the desired bilamellar microstructure. For each heat treatment condition, different α–β microstructures were found, varying in terms of the α/β ratio and the size of the primary α-phase lamellae. Particular attention was given to how these factors were influenced by increases in solution temperature and how microhardness correlated with the percentage of the metastable β phase present after quenching. Tensile tests were performed on samples subjected to the most promising heat treatment parameters. A comparison with literature data revealed that the optimized STA treatment enhanced hardness and UTS by 13% and 23%, respectively, compared with those of the annealed alloy. Fracture surface analyses were conducted to investigate fracture mechanisms.
Ti–6Al–4Zr–2Sn–6Mo alloy is one of the most recent titanium alloys processed using powder bed fusion–laser beam (PBF–LB) technology. This alloy has the potential to replace Ti–6Al–4V in automotive and aerospace applications, given its superior mechanical properties, which are approximately 10% higher in terms of ultimate tensile strength (UTS) and yield strength after appropriate heat treatment. In as-built conditions, the alloy is characterized by the presence of soft orthorhombic α″ martensite, necessitating a postprocessing heat treatment to decompose this phase and enhance the mechanical properties of the alloy. Usually, PBFed Ti6246 components undergo an annealing process that transforms the α″ martensite into an α–β lamellar microstructure. The primary objective of this research was to develop a solution treatment and aging (STA) heat treatment tailored to the unique microstructure produced by the additive manufacturing process to achieve an ultrafine bilamellar microstructure reinforced by precipitation hardening. This study investigated the effects of various solution temperatures in the α–β field (ranging from 800 to 875°C), cooling media (air and water), and aging time to determine the optimal heat treatment parameters for achieving the desired bilamellar microstructure. For each heat treatment condition, different α–β microstructures were found, varying in terms of the α/β ratio and the size of the primary α-phase lamellae. Particular attention was given to how these factors were influenced by increases in solution temperature and how microhardness correlated with the percentage of the metastable β phase present after quenching. Tensile tests were performed on samples subjected to the most promising heat treatment parameters. A comparison with literature data revealed that the optimized STA treatment enhanced hardness and UTS by 13% and 23%, respectively, compared with those of the annealed alloy. Fracture surface analyses were conducted to investigate fracture mechanisms.
2025, vol. 32, no. 2, pp.
425-438.
https://doi.org/10.1007/s12613-024-2945-1
Abstract:
At present, the emerging solid-phase friction-based additive manufacturing technology, including friction rolling additive manufacturing (FRAM), can only manufacture simple single-pass components. In this study, multi-layer multi-pass FRAM-deposited aluminum alloy samples were successfully prepared using a non-shoulder tool head. The material flow behavior and microstructure of the overlapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys. The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adjacent passes in the overlapped center area. Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone, which made the recrystallization degree in the left and right edge zones of the overlapped zone the highest, followed by the overlapped center zone and the non-overlapped zone. The tensile strength of the overlapped zone exceeded 90% of that of the single-pass deposition sample. It is proved that although there are uneven grooves on the surface of the overlapping area during multi-layer and multi-pass deposition, they can be filled by the flow of materials during the deposition of the next layer, thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area. The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.
At present, the emerging solid-phase friction-based additive manufacturing technology, including friction rolling additive manufacturing (FRAM), can only manufacture simple single-pass components. In this study, multi-layer multi-pass FRAM-deposited aluminum alloy samples were successfully prepared using a non-shoulder tool head. The material flow behavior and microstructure of the overlapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys. The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adjacent passes in the overlapped center area. Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone, which made the recrystallization degree in the left and right edge zones of the overlapped zone the highest, followed by the overlapped center zone and the non-overlapped zone. The tensile strength of the overlapped zone exceeded 90% of that of the single-pass deposition sample. It is proved that although there are uneven grooves on the surface of the overlapping area during multi-layer and multi-pass deposition, they can be filled by the flow of materials during the deposition of the next layer, thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area. The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.
2025, vol. 32, no. 2, pp.
439-449.
https://doi.org/10.1007/s12613-024-2928-2
Abstract:
The local structure and thermophysical behavior of Mg–La liquid alloys were in-depth understood using deep potential molecular dynamic (DPMD) simulation driven via machine learning to promote the development of Mg–La alloys. The robustness of the trained deep potential (DP) model was thoroughly evaluated through several aspects, including root-mean-square errors (RMSEs), energy and force data, and structural information comparison results; the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg–La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg–La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg–La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg–La liquid alloy at 1200 K were reliably evaluated, which provides new guidance for related studies.
The local structure and thermophysical behavior of Mg–La liquid alloys were in-depth understood using deep potential molecular dynamic (DPMD) simulation driven via machine learning to promote the development of Mg–La alloys. The robustness of the trained deep potential (DP) model was thoroughly evaluated through several aspects, including root-mean-square errors (RMSEs), energy and force data, and structural information comparison results; the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg–La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg–La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg–La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg–La liquid alloy at 1200 K were reliably evaluated, which provides new guidance for related studies.
2025, vol. 32, no. 2, pp.
450-463.
https://doi.org/10.1007/s12613-024-2927-3
Abstract:
We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg alloy. This composite comprised a tungstate-intercalated (LDH-W) underlayer that was grown at low temperature (relative to hydrothermal reaction conditions) under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane (PFDTMS) using a simple immersion method. The successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the LDH-W film, both before and after the PFDTMS modification, was evaluated using electrochemical impedance spectroscopy (EIS), Tafel curves, and immersion experiments. The results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDH-W film, with no apparent signs of corrosion after exposure to 3.5wt% NaCl solution for 15 d. Furthermore, the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages, as confirmed by static contact angle and water-repellency tests. These results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.
We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg alloy. This composite comprised a tungstate-intercalated (LDH-W) underlayer that was grown at low temperature (relative to hydrothermal reaction conditions) under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane (PFDTMS) using a simple immersion method. The successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the LDH-W film, both before and after the PFDTMS modification, was evaluated using electrochemical impedance spectroscopy (EIS), Tafel curves, and immersion experiments. The results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDH-W film, with no apparent signs of corrosion after exposure to 3.5wt% NaCl solution for 15 d. Furthermore, the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages, as confirmed by static contact angle and water-repellency tests. These results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.
2025, vol. 32, no. 2, pp.
464-475.
https://doi.org/10.1007/s12613-024-2930-8
Abstract:
Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications. Coal tar residues (CTR), as a type of carbon-rich solid waste with high value-added utilization, are crucially important for the development of a more sustainable world. In this study, we employed a straightforward direct carbonization method within the temperature range of 700–1000°C to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries (PIBs). The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons (CTRCs) were systematically explored by structural and morphological characterization, alongside electrochemical performances assessment. Based on the co-regulation between the turbine layers, crystal structure, pore structure, functional groups, and electrical conductivity of CTR-derived carbon carbonized at 900°C (CTRC-900H), the electrode material with high reversible capacity of 265.6 mAh·g−1 at 50 mA·g−1, a desirable cycling stability with 93.8% capacity retention even after 100 cycles, and the remarkable rate performance for PIBs were obtained. Furthermore, cyclic voltammetry (CV) at different scan rates and galvanostatic intermittent titration technique (GITT) have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of CTRCs. Results indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes, particularly under high current densities, with the potassium storage mechanism characterized by an “adsorption–weak intercalation” mechanism. This work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes, while also provides valuable insights into the new avenues for the high value-added utilization of CTR.
Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications. Coal tar residues (CTR), as a type of carbon-rich solid waste with high value-added utilization, are crucially important for the development of a more sustainable world. In this study, we employed a straightforward direct carbonization method within the temperature range of 700–1000°C to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries (PIBs). The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons (CTRCs) were systematically explored by structural and morphological characterization, alongside electrochemical performances assessment. Based on the co-regulation between the turbine layers, crystal structure, pore structure, functional groups, and electrical conductivity of CTR-derived carbon carbonized at 900°C (CTRC-900H), the electrode material with high reversible capacity of 265.6 mAh·g−1 at 50 mA·g−1, a desirable cycling stability with 93.8% capacity retention even after 100 cycles, and the remarkable rate performance for PIBs were obtained. Furthermore, cyclic voltammetry (CV) at different scan rates and galvanostatic intermittent titration technique (GITT) have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of CTRCs. Results indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes, particularly under high current densities, with the potassium storage mechanism characterized by an “adsorption–weak intercalation” mechanism. This work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes, while also provides valuable insights into the new avenues for the high value-added utilization of CTR.
2025, vol. 32, no. 2, pp.
476-487.
https://doi.org/10.1007/s12613-024-2958-9
Abstract:
Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for developing rechargeable zinc–air batteries (ZABs). Herein, an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere (NCS) decorated with dual-phase Co/Co7Fe3 heterojunctions (CoFe@NCS). The phase composition of materials has been adjusted by controlling the alloying degree. The optimal CoFe0.08@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm−2 for OER in an alkaline electrolyte. The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co7Fe3 alloy and metallic Co species. When the CoFe0.08@NCS material is used as air–cathode catalyst of rechargeable liquid-state zinc–air battery (ZAB), the device shows a high peak power-density (157 mW·cm−2) and maintains a stable voltage gap over 150 h, outperforming those of the benchmark (Pt/C+RuO2)-based device. In particular, the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions. Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.
Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for developing rechargeable zinc–air batteries (ZABs). Herein, an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere (NCS) decorated with dual-phase Co/Co7Fe3 heterojunctions (CoFe@NCS). The phase composition of materials has been adjusted by controlling the alloying degree. The optimal CoFe0.08@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm−2 for OER in an alkaline electrolyte. The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co7Fe3 alloy and metallic Co species. When the CoFe0.08@NCS material is used as air–cathode catalyst of rechargeable liquid-state zinc–air battery (ZAB), the device shows a high peak power-density (157 mW·cm−2) and maintains a stable voltage gap over 150 h, outperforming those of the benchmark (Pt/C+RuO2)-based device. In particular, the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions. Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.
2025, vol. 32, no. 2, pp.
488-497.
https://doi.org/10.1007/s12613-024-2920-x
Abstract:
BiVO4 porous spheres modified by ZnO were designed and synthesized using a facile two-step method. The resulting ZnO/BiVO4 composite catalysts have shown remarkable efficiency as piezoelectric catalysts for degrading Rhodamine B (RhB) under mechanical vibrations, they exhibit superior activity compared to pure ZnO. The 40wt% ZnO/BiVO4 heterojunction composite displayed the highest activity, along with good stability and recyclability. The enhanced piezoelectric catalytic activity can be attributed to the formation of an I-scheme heterojunction structure, which can effectively inhibit the electron-hole recombination. Furthermore, hole (h+) and superoxide radical (\begin{document}$\cdot \mathrm{O}_2^- $\end{document}
BiVO4 porous spheres modified by ZnO were designed and synthesized using a facile two-step method. The resulting ZnO/BiVO4 composite catalysts have shown remarkable efficiency as piezoelectric catalysts for degrading Rhodamine B (RhB) under mechanical vibrations, they exhibit superior activity compared to pure ZnO. The 40wt% ZnO/BiVO4 heterojunction composite displayed the highest activity, along with good stability and recyclability. The enhanced piezoelectric catalytic activity can be attributed to the formation of an I-scheme heterojunction structure, which can effectively inhibit the electron-hole recombination. Furthermore, hole (h+) and superoxide radical (
2025, vol. 32, no. 2, pp.
498-503.
https://doi.org/10.1007/s12613-024-2965-x
Abstract:
Zinc oxide (ZnO) serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 eV. Solvothermal reaction is commonly used in the synthesis of ZnO micro/nanostructures, given its low cost, simplicity, and easy implementation. Moreover, ZnO morphology engineering has become desirable through the alteration of minor conditions in the reaction process, particularly at room temperature. In this work, ZnO micro/nanostructures were synthesized in a solution by varying the amounts of the ammonia added at low temperatures (including room temperature). The formation of Zn2+ complexes by ammonia in the precursor regulated the reaction rate of the morphology engineering of ZnO, which resulted in various structures, such as nanoparticles, nanosheets, microflowers, and single crystals. Finally, the obtained ZnO was used in the optoelectronic application of ultraviolet detectors.
Zinc oxide (ZnO) serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 eV. Solvothermal reaction is commonly used in the synthesis of ZnO micro/nanostructures, given its low cost, simplicity, and easy implementation. Moreover, ZnO morphology engineering has become desirable through the alteration of minor conditions in the reaction process, particularly at room temperature. In this work, ZnO micro/nanostructures were synthesized in a solution by varying the amounts of the ammonia added at low temperatures (including room temperature). The formation of Zn2+ complexes by ammonia in the precursor regulated the reaction rate of the morphology engineering of ZnO, which resulted in various structures, such as nanoparticles, nanosheets, microflowers, and single crystals. Finally, the obtained ZnO was used in the optoelectronic application of ultraviolet detectors.
2025, vol. 32, no. 2, pp.
504-514.
https://doi.org/10.1007/s12613-024-2978-5
Abstract:
Silver nanoparticles (Ag NPs) have attracted attention in the field of biomaterials due to their excellent antibacterial property. However, the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water pollution. In this work, Ag NPs (31.2 nm in diameter) were prepared using the extract of straw, an agricultural waste, as the reducing and stabilizing agent. Experimental analysis revealed that the straw extract contained lignin, the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag NPs. The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation. After the prepared Ag NPs were added to the precursor solution of acrylamide, free radical polymerization was triggered without the need for extra heating or light irradiation, resulting in the rapid formation of an Ag NP–polyacrylamide composite hydrogel. The inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag NPs. The prepared hydrogel may have potential applications in the fabrication of biomedical materials, such as antibacterial dressings.
Silver nanoparticles (Ag NPs) have attracted attention in the field of biomaterials due to their excellent antibacterial property. However, the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water pollution. In this work, Ag NPs (31.2 nm in diameter) were prepared using the extract of straw, an agricultural waste, as the reducing and stabilizing agent. Experimental analysis revealed that the straw extract contained lignin, the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag NPs. The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation. After the prepared Ag NPs were added to the precursor solution of acrylamide, free radical polymerization was triggered without the need for extra heating or light irradiation, resulting in the rapid formation of an Ag NP–polyacrylamide composite hydrogel. The inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag NPs. The prepared hydrogel may have potential applications in the fabrication of biomedical materials, such as antibacterial dressings.
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