N掺杂石墨烯量子点修饰的N-TiO2/P掺杂多孔g-C3N4纳米管复合光催化剂用于降解抗生素和产氢

袁静舒; 张瑶; 张笑妍; 张俊杰; 张深根

doi:10.1007/s12613-023-2678-6

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文章导航 > 矿物冶金与材料学报（英文） > 2024 > 31(1): 165-178

Jingshu Yuan, Yao Zhang, Xiaoyan Zhang, Junjie Zhang, and Shen’gen Zhang, N-doped graphene quantum dot-decorated N-TiO₂/P-doped porous hollow g-C₃N₄ nanotube composite photocatalysts for antibiotic photodegradation and H₂ production, Int. J. Miner. Metall. Mater., 31(2024), No. 1, pp. 165-178. https://doi.org/10.1007/s12613-023-2678-6

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Jingshu Yuan, Yao Zhang, Xiaoyan Zhang, Junjie Zhang, and Shen’gen Zhang, N-doped graphene quantum dot-decorated N-TiO2/P-doped porous hollow g-C3N4 nanotube composite photocatalysts for antibiotic photodegradation and H2 production, Int. J. Miner. Metall. Mater., 31(2024), No. 1, pp. 165-178. https://doi.org/10.1007/s12613-023-2678-6

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研究论文

N掺杂石墨烯量子点修饰的N-TiO₂/P掺杂多孔g-C₃N₄纳米管复合光催化剂用于降解抗生素和产氢

1)
北京科技大学新材料技术研究院，北京 100083，中国
2)
西安翻译学院，西安 710105，中国
3)
北京科技大学顺德研究生院，佛山 528399，中国
4)
澳门科技大学月球与行星科学国家重点实验室，澳门特别行政区 820000，中国

通讯作者:
张深根 E-mail: zhangshengen@mater.ustb.edu.cn

文章亮点

(1) 合成了一种新型N-GQDs/N-TiO₂/P-g-C₃N₄多孔纳米管光催化剂。

(2) 实现了长波光源高效利用及光生电子定向转移。

(3) 阐明了N/P掺杂、Z型异质结、形貌调控及N-GQDs耦合的协同改性机制。

(4) 提出了0.1%G-TPCN的光催化反应机理及环丙沙星可能的5种降解路径。

中文摘要

仅响应紫外光(~3.2 eV)和光生电荷复合率高是纯TiO₂的两个主要缺点。本文联合N掺杂石墨烯量子点(N-GQDs)、形貌调控和异质结构筑合成了N-GQD/N掺杂TiO₂/P掺杂多孔中空g-C₃N₄纳米管(PCN)复合光催化剂(简称G-TPCN)。最佳样品(掺杂0.1wt% N-GQD的G-TPCN，记为0.1%G-TPCN)的光吸收性能显著增强，归因于P/N元素掺杂改变带隙、管状结构改善光捕集以及N-GQDs的上转换效应。此外，0.1%G-TPCN内部电荷分离和转移能力显著提高，其载流子浓度分别是N-TiO₂、PCN和N-TiO₂/PCN (TPCN-1)的3.7倍、2.3倍和1.9倍。这一结果归因于N-TiO₂与PCN之间形成的Z型异质结、N-GQDs优异的电子传导能力及多孔纳米管结构缩短电荷传输距离。与N-TiO₂、PCN和TPCN-1相比，0.1%G-TPCN在可见光下产H₂活性分别提高了12.4、2.3和1.4倍，环丙沙星(CIP)降解率分别提高了7.9、5.7和2.9倍。优化的性能得益于出色的光响应能力及提高的载流子分离和迁移效率。最后，提出了0.1%G-TPCN的光催化机理及CIP可能的五种降解途径。本研究阐明了多种改性策略协同提高0.1%G-TPCN光催化性能的机制，为合理设计新型光催化剂用于环境修复和太阳能转换提供了一种潜在方法。

关键词:

Research Article

N-doped graphene quantum dot-decorated N-TiO₂/P-doped porous hollow g-C₃N₄ nanotube composite photocatalysts for antibiotic photodegradation and H₂ production

+ Author Affiliations

1)
Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
2)
Xi’an Fanyi University, Xi’an 710105, China
3)
Shunde Graduate School of University of Science and Technology Beijing, Foshan 528399, China
4)
State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau SAR 820000, China

The authors declare no conflicts of interest.
The online version contains supplementary material at https://doi.org/10.1007/s12613-023-2678-6.
* These authors contributed equally to this work

Corresponding author:
Shen’gen Zhang E-mail: zhangshengen@mater.ustb.edu.cn
Received: 18 February 2023; Revised: 15 May 2023; Accepted: 16 May 2023; Available online: 17 May 2023

Abstract

Abstract

Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO₂. We combined N-doped graphene quantum dots (N-GQDs), morphology regulation, and heterojunction construction strategies to synthesize N-GQD/N-doped TiO₂/P-doped porous hollow g-C₃N₄ nanotube (PCN) composite photocatalysts (denoted as G-TPCN). The optimal sample (G-TPCN doped with 0.1wt% N-GQD, denoted as 0.1%G-TPCN) exhibits significantly enhanced photoabsorption, which is attributed to the change in bandgap caused by elemental doping (P and N), the improved light-harvesting resulting from the tube structure, and the upconversion effect of N-GQDs. In addition, the internal charge separation and transfer capability of 0.1%G-TPCN are dramatically boosted, and its carrier concentration is 3.7, 2.3, and 1.9 times that of N-TiO₂, PCN, and N-TiO₂/PCN (TPCN-1), respectively. This phenomenon is attributed to the formation of Z-scheme heterojunction between N-TiO₂ and PCNs, the excellent electron conduction ability of N-GQDs, and the short transfer distance caused by the porous nanotube structure. Compared with those of N-TiO₂, PCNs, and TPCN-1, the H₂ production activity of 0.1%G-TPCN under visible light is enhanced by 12.4, 2.3, and 1.4 times, respectively, and its ciprofloxacin (CIP) degradation rate is increased by 7.9, 5.7, and 2.9 times, respectively. The optimized performance benefits from excellent photoresponsiveness and improved carrier separation and migration efficiencies. Finally, the photocatalytic mechanism of 0.1%G-TPCN and five possible degradation pathways of CIP are proposed. This study clarifies the mechanism of multiple modification strategies to synergistically improve the photocatalytic performance of 0.1%G-TPCN and provides a potential strategy for rationally designing novel photocatalysts for environmental remediation and solar energy conversion.
- N-doped TiO₂;
- N-doped graphene quantum dots;
- P-doped g-C₃N₄;
- porous hollow nanotube;
- heterojunction;
- photocatalysis

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References

[1]	S.J. Wang, F.T. He, X.L. Zhao, et al., Phosphorous doped carbon nitride nanobelts for photodegradation of emerging contaminants and hydrogen evolution, Appl. Catal. B: Environ., 257(2019), art. No. 117931. doi: 10.1016/j.apcatb.2019.117931
[2]	H.H. Wang, W.X. Liu, J. Ma, et al., Design of (GO/TiO₂)N one-dimensional photonic crystal photocatalysts with improved photocatalytic activity for tetracycline degradation, Int. J. Miner. Metall. Mater., 27(2020), No. 6, p. 830. doi: 10.1007/s12613-019-1923-5
[3]	J. Li, M. Zhang, Q.Y. Li, and J.J. Yang, Enhanced visible light activity on direct contact Z-scheme g-C₃N₄-TiO₂ photocatalyst, Appl. Surf. Sci., 391(2017), p. 184. doi: 10.1016/j.apsusc.2016.06.145
[4]	X.H. Jiang, Y.N. Duan, Y. Tian, et al., Facile one-pot hydrothermal method to prepare Sn(II) and N co-doped TiO₂ photocatalyst for water splitting under visible light irradiation, Rare Met., 41(2022), No. 2, p. 406. doi: 10.1007/s12598-021-01810-4
[5]	X.F. Chen, J. Wei, R.J. Hou, et al., Growth of g-C₃N₄ on mesoporous TiO₂ spheres with high photocatalytic activity under visible light irradiation, Appl. Catal. B: Environ., 188(2016), p. 342. doi: 10.1016/j.apcatb.2016.02.012
[6]	Y.C. Nie, F. Yu, L.C. Wang, et al., Photocatalytic degradation of organic pollutants coupled with simultaneous photocatalytic H₂ evolution over graphene quantum dots/Mn-N-TiO₂/g-C₃N₄ composite catalysts: Performance and mechanism, Appl. Catal. B: Environ., 227(2018), p. 312. doi: 10.1016/j.apcatb.2018.01.033
[7]	Y.Y. Qin, Y.C. Guo, Z.Q. Liang, et al., Au nanorods decorated TiO₂ nanobelts with enhanced full solar spectrum photocatalytic antibacterial activity and the sterilization file cabinet application, Chin. Chem. Lett., 32(2021), No. 4, p. 1523. doi: 10.1016/j.cclet.2020.10.020
[8]	L. Xu, X. Bai, L.K. Guo, S.J. Yang, P.K. Jin, and L. Yang, Facial fabrication of carbon quantum dots (CDs)-modified N-TiO_2−x nanocomposite for the efficient photoreduction of Cr(VI) under visible light, Chem. Eng. J., 357(2019), p. 473. doi: 10.1016/j.cej.2018.09.172
[9]	S. Dong, S.H. Chen, F.Y. He, J.C. Li, H. Li, and K.Z. Xu, Construction of a novel N-doped oxygen vacancy-rich TiO₂ N-TiO_2−X/g-C₃N₄ S-scheme heterostructure for visible light driven photocatalytic degradation of 2,4-dinitrophenylhydrazine, J. Alloys Compd., 908(2022), art. No. 164586. doi: 10.1016/j.jallcom.2022.164586
[10]	L. Yang, X. Bai, J. Shi, X.Y. Du, L. Xu, and P.K. Jin, Quasi-full-visible-light absorption by D35-TiO₂/g-C₃N₄ for synergistic persulfate activation towards efficient photodegradation of micropollutants, Appl. Catal. B: Environ., 256(2019), art. No. 117759. doi: 10.1016/j.apcatb.2019.117759
[11]	B. Fang, Z.P. Xing, D.D. Sun, Z.Z. Li, and W. Zhou, Hollow semiconductor photocatalysts for solar energy conversion, Adv. Powder Mater., 1(2022), No. 2, art. No. 100021. doi: 10.1016/j.apmate.2021.11.008
[12]	Y.X. Wang, L. Rao, P.F. Wang, Z.Y. Shi, and L.X. Zhang, Photocatalytic activity of N-TiO₂/O-doped N vacancy g-C₃N₄ and the intermediates toxicity evaluation under tetracycline hydrochloride and Cr(VI) coexistence environment, Appl. Catal. B: Environ., 262(2020), art. No. 118308. doi: 10.1016/j.apcatb.2019.118308
[13]	L.Q. Zhang, X. He, X.W. Xu, et al., Highly active TiO₂/g-C₃N₄/G photocatalyst with extended spectral response towards selective reduction of nitrobenzene, Appl. Catal. B: Environ., 203(2017), p. 1. doi: 10.1016/j.apcatb.2016.10.003
[14]	R.Y. Zhong, Z.S. Zhang, H.Q. Yi, et al., Covalently bonded 2D/2D O-g-C₃N₄/TiO₂ heterojunction for enhanced visible-light photocatalytic hydrogen evolution, Appl. Catal. B: Environ., 237(2018), p. 1130. doi: 10.1016/j.apcatb.2017.12.066
[15]	Y. Zhang, J.S. Yuan, L. Zhao, et al., Boosting exciton dissociation and charge transfer in P-doped 2D porous g-C₃N₄ for enhanced H₂ production and molecular oxygen activation, Ceram. Int., 48(2022), No. 3, p. 4031. doi: 10.1016/j.ceramint.2021.10.193
[16]	Y.C. Deng, L. Tang, G.M. Zeng, et al., Insight into highly efficient simultaneous photocatalytic removal of Cr(VI) and 2,4-diclorophenol under visible light irradiation by phosphorus doped porous ultrathin g-C₃N₄ nanosheets from aqueous media: Performance and reaction mechanism, Appl. Catal. B: Environ., 203(2017), p. 343. doi: 10.1016/j.apcatb.2016.10.046
[17]	N. Tian, K. Xiao, Y.H. Zhang, et al., Reactive sites rich porous tubular yolk-shell g-C₃N₄ via precursor recrystallization mediated microstructure engineering for photoreduction, Appl. Catal. B: Environ., 253(2019), p. 196. doi: 10.1016/j.apcatb.2019.04.036
[18]	Y.H. Li, M.L. Gu, T. Shi, et al., Carbon vacancy in C₃N₄ nanotube: Electronic structure, photocatalysis mechanism and highly enhanced activity, Appl. Catal. B: Environ., 262(2020), art. No. 118281. doi: 10.1016/j.apcatb.2019.118281
[19]	Y. Zhang, J.S. Yuan, Y.J. Ding, B.L. Zhang, S.G. Zhang, and B. Liu, Metal-free N-GQDs/P-g-C₃N₄ photocatalyst with broad-spectrum response: Enhanced exciton dissociation and charge migration for promoting H₂ evolution and tetracycline degradation, Sep. Purif. Technol., 304(2023), art. No. 122297. doi: 10.1016/j.seppur.2022.122297
[20]	Y.H. Su, G.L. Liu, C.P. Zeng, Y.B. Lu, H.P. Luo, and R.D. Zhang, Carbon quantum dots-decorated TiO₂/g-C₃N₄ film electrode as a photoanode with improved photoelectrocatalytic performance for 1,4-dioxane degradation, Chemosphere, 251(2020), art. No. 126381. doi: 10.1016/j.chemosphere.2020.126381
[21]	T. Chen, L. Zhong, Z. Yang, et al., Enhanced visible-light photocatalytic activity of g-C₃N₄/nitrogen-doped graphene quantum dots/TiO₂ ternary heterojunctions for ciprofloxacin degradation with narrow band gap and high charge carrier mobility, Chem. Res. Chin. Univ., 36(2020), No. 6, p. 1083. doi: 10.1007/s40242-020-0301-1
[22]	Y.C. Deng, L. Tang, C.Y. Feng, et al., Construction of plasmonic Ag and nitrogen-doped graphene quantum dots codecorated ultrathin graphitic carbon nitride nanosheet composites with enhanced photocatalytic activity: Full-spectrum response ability and mechanism insight, ACS Appl. Mater. Interfaces, 9(2017), No. 49, p. 42816. doi: 10.1021/acsami.7b14541
[23]	Y. Zhang, J.S. Yuan, Y.J. Ding, B. Liu, L. Zhao, and S.G. Zhang, Research progress on g-C₃N₄-based photocatalysts for organic pollutants degradation in wastewater: From exciton and carrier perspectives, Ceram. Int., 47(2021), No. 22, p. 31005. doi: 10.1016/j.ceramint.2021.08.063
[24]	W.J. Wang, Z.T. Zeng, G.M. Zeng, et al., Sulfur doped carbon quantum dots loaded hollow tubular g-C₃N₄ as novel photocatalyst for destruction of Escherichia coli and tetracycline degradation under visible light, Chem. Eng. J., 378(2019), art. No. 122132. doi: 10.1016/j.cej.2019.122132
[25]	Z. Mo, X.W. Zhu, Z.F. Jiang, et al., Porous nitrogen-rich g-C₃N₄ nanotubes for efficient photocatalytic CO₂ reduction, Appl. Catal. B: Environ., 256(2019), art. No. 117854. doi: 10.1016/j.apcatb.2019.117854
[26]	N. Fajrina and M. Tahir, 2D-montmorillonite-dispersed g-C₃N₄/TiO₂ 2D/0Dnanocomposite for enhanced photo-induced H₂ evolution from glycerol–water mixture, Appl. Surf. Sci., 471(2019), p. 1053. doi: 10.1016/j.apsusc.2018.12.076
[27]	M.H. Zhang, N. Han, Y.W. Fei, et al., TiO₂/g-C₃N₄ photocatalyst for the purification of potassium butyl xanthate in mineral processing wastewater, J. Environ. Manag., 297(2021), art. No. 113311. doi: 10.1016/j.jenvman.2021.113311
[28]	Z. Lu, L. Zeng, W.L. Song, Z.Y. Qin, D.W. Zeng, and C.S. Xie, In situ synthesis of C–TiO₂/g-C₃N₄ heterojunction nanocomposite as highly visible light active photocatalyst originated from effective interfacial charge transfer, Appl. Catal. B: Environ., 202(2017), p. 489. doi: 10.1016/j.apcatb.2016.09.052
[29]	L. Chen, X.L. Zhao, X.G. Duan, et al., Graphitic carbon nitride microtubes for efficient photocatalytic overall water splitting: The morphology derived electrical field enhancement, ACS Sustainable Chem. Eng., 8(2020), No. 38, p. 14386. doi: 10.1021/acssuschemeng.0c04097
[30]	S.E. Guo, Z.P. Deng, M.X. Li, et al., Phosphorus-doped carbon nitride tubes with a layered micro-nanostructure for enhanced visible-light photocatalytic hydrogen evolution, Angew. Chem. Int. Ed., 55(2016), No. 5, p. 1830. doi: 10.1002/anie.201508505
[31]	Y.Y. Jiao, Y.K. Li, J.S. Wang, Z.H. He, and Z.J. Li, Double Z-scheme photocatalyst C₃N₄ nanotube/N-doped carbon dots/Ni₂P with enhanced visible-light photocatalytic activity for hydrogen generation, Appl. Surf. Sci., 534(2020), art. No. 147603. doi: 10.1016/j.apsusc.2020.147603
[32]	G.H. Zhang, T.Y. Zhang, B. Li, et al., An ingenious strategy of preparing TiO₂/g-C₃N₄ heterojunction photocatalyst: In situ growth of TiO₂ nanocrystals on g-C₃N₄ nanosheets via impregnation-calcination method, Appl. Surf. Sci., 433(2018), p. 963. doi: 10.1016/j.apsusc.2017.10.135
[33]	G.D. Jiang, K. Geng, Y. Wu, Y.H. Han, and X.D. Shen, High photocatalytic performance of ruthenium complexes sensitizing g-C₃N₄/TiO₂ hybrid in visible light irradiation, Appl. Catal. B: Environ., 227(2018), p. 366. doi: 10.1016/j.apcatb.2018.01.034
[34]	G.M. Jiang, J.W. Cao, M. Chen, X.M. Zhang, and F. Dong, Photocatalytic NO oxidation on N-doped TiO₂/g-C₃N₄ heterojunction: Enhanced efficiency, mechanism and reaction pathway, Appl. Surf. Sci., 458(2018), p. 77. doi: 10.1016/j.apsusc.2018.07.087
[35]	Y. Zhao, S.P. Xu, X. Sun, X. Xu, and B.Y. Gao, Unique bar-like sulfur-doped C₃N₄/TiO₂ nanocomposite: Excellent visible light driven photocatalytic activity and mechanism study, Appl. Surf. Sci., 436(2018), p. 873. doi: 10.1016/j.apsusc.2017.12.061
[36]	H.Y. Niu, W.J. Zhao, H.Z. Lv, Y.L. Yang, and Y.Q. Cai, Accurate design of hollow/tubular porous g-C₃N₄ from melamine-cyanuric acid supramolecular prepared with mechanochemical method, Chem. Eng. J., 411(2021), art. No. 128400. doi: 10.1016/j.cej.2020.128400
[37]	K. Wei, K.X. Li, L.S. Yan, et al., One-step fabrication of g-C₃N₄ nanosheets/TiO₂ hollow microspheres heterojunctions with atomic level hybridization and their application in the multi-component synergistic photocatalytic systems, Appl. Catal. B: Environ., 222(2018), p. 88. doi: 10.1016/j.apcatb.2017.09.070
[38]	X.H. Jiang, Q.J. Xing, X.B. Luo, et al., Simultaneous photoreduction of Uranium(VI) and photooxidation of Arsenic(III) in aqueous solution over g-C₃N₄/TiO₂ heterostructured catalysts under simulated sunlight irradiation, Appl. Catal. B: Environ., 228(2018), p. 29. doi: 10.1016/j.apcatb.2018.01.062
[39]	M.N. Huang, J.H. Yu, Q. Hu, et al., Preparation and enhanced photocatalytic activity of carbon nitride/titania (001 vs 101 facets)/reduced graphene oxide (g-C₃N₄/TiO₂/rGO) hybrids under visible light, Appl. Surf. Sci., 389(2016), p. 1084. doi: 10.1016/j.apsusc.2016.07.180
[40]	Y.G. Tan, Z. Shu, J. Zhou, T.T. Li, W.B. Wang, and Z.L. Zhao, One-step synthesis of nanostructured g-C₃N₄/TiO₂ composite for highly enhanced visible-light photocatalytic H₂ evolution, Appl. Catal. B: Environ., 230(2018), p. 260. doi: 10.1016/j.apcatb.2018.02.056
[41]	X.Q. Wang, F. Wang, C. Bo, et al., Promotion of phenol photodecomposition and the corresponding decomposition mechanism over g-C₃N₄/TiO₂ nanocomposites, Appl. Surf. Sci., 453(2018), p. 320. doi: 10.1016/j.apsusc.2018.05.082
[42]	D. Yang, X.Y. Zhao, Y. Chen, et al., Synthesis of g-C₃N₄ nanosheet/TiO₂ heterojunctions inspired by bioadhesion and biomineralization mechanism, Ind. Eng. Chem. Res., 58(2019), No. 14, p. 5516. doi: 10.1021/acs.iecr.9b00184
[43]	F.X. Li, X.D. Xiao, C. Zhao, et al., TiO₂-on-C₃N₄ double-shell microtubes: In-situ fabricated heterostructures toward enhanced photocatalytic hydrogen evolution, J. Colloid Interface Sci., 572(2020), p. 22. doi: 10.1016/j.jcis.2020.03.071
[44]	Y.Y. Yin, Q. Liu, D. Jiang, et al., Atmospheric pressure synthesis of nitrogen doped graphene quantum dots for fabrication of BiOBr nanohybrids with enhanced visible-light photoactivity and photostability, Carbon, 96(2016), p. 1157. doi: 10.1016/j.carbon.2015.10.068
[45]	L.N. Chi, Y.J. Qian, J.Q. Guo, X.Z. Wang, H. Arandiyan, and Z. Jiang, Novel g-C₃N₄/TiO₂/PAA/PTFE ultrafiltration membrane enabling enhanced antifouling and exceptional visible-light photocatalytic self-cleaning, Catal. Today, 335(2019), p. 527. doi: 10.1016/j.cattod.2019.02.027
[46]	K.L. Huang, C.H. Li, X.L. Zhang, et al., TiO₂ nanorod arrays decorated by nitrogen-doped carbon and g-C₃N₄ with enhanced photoelectrocatalytic activity, Appl. Surf. Sci., 518(2020), art. No. 146219. doi: 10.1016/j.apsusc.2020.146219
[47]	J. Ma, W. Zhou, X. Tan, and T. Yu, Potassium ions intercalated into g-C₃N₄-modified TiO₂ nanobelts for the enhancement of photocatalytic hydrogen evolution activity under visible-light irradiation, Nanotechnology, 29(2018), No. 21, art. No. 215706. doi: 10.1088/1361-6528/aab564
[48]	C.X. Li, Z.R. Lou, Y.C. Yang, et al., Hollowsphere nanoheterojunction of g-C₃N₄@TiO₂ with high visible light photocatalytic property, Langmuir, 35(2019), No. 3, p. 779. doi: 10.1021/acs.langmuir.8b03867
[49]	J. Ma, X. Tan, T. Yu, and X.L. Li, Fabrication of g-C₃N₄/TiO₂ hierarchical spheres with reactive{001}TiO₂ crystal facets and its visible-light photocatalytic activity, Int. J. Hydrog. Energy, 41(2016), No. 6, p. 3877. doi: 10.1016/j.ijhydene.2015.12.191
[50]	Z.B. Wu, Y.S. Liang, X.Z. Yuan, et al., MXene Ti₃C₂ derived Z-scheme photocatalyst of graphene layers anchored TiO₂/g-C₃N₄ for visible light photocatalytic degradation of refractory organic pollutants, Chem. Eng. J., 394(2020), art. No. 124921. doi: 10.1016/j.cej.2020.124921
[51]	Q.H. Li, M. Dong, R. Li, et al., Enhancement of Cr(VI) removal efficiency via adsorption/photocatalysis synergy using electrospun chitosan/g-C₃N₄/TiO₂ nanofibers, Carbohydr. Polym., 253(2021), art. No. 117200. doi: 10.1016/j.carbpol.2020.117200
[52]	X. Han, L. An, Y. Hu, et al., Ti₃C₂ MXene-derived carbon-doped TiO₂ coupled with g-C₃N₄ as the visible-light photocatalysts for photocatalytic H₂ generation, Appl. Catal. B: Environ., 265(2020), art. No. 118539. doi: 10.1016/j.apcatb.2019.118539
[53]	J.Q. Pan, Z.J. Dong, B.B. Wang, et al., The enhancement of photocatalytic hydrogen production via Ti³⁺ self-doping black TiO₂/g-C₃N₄ hollow core-shell nano-heterojunction, Appl. Catal. B: Environ., 242(2019), p. 92. doi: 10.1016/j.apcatb.2018.09.079
[54]	B. Zhou, H.T. Hong, H.F. Zhang, S.S. Yu, and H.W. Tian, Heterostructured Ag/g-C₃N₄/TiO₂ with enhanced visible light photocatalytic performances, J. Chem. Technol. Biotechnol., 94(2019), No. 12, p. 3806. doi: 10.1002/jctb.6105
[55]	Y.J. Zou, J.W. Shi, D.D. Ma, Z.Y. Fan, C.M. Niu, and L.Z. Wang, Fabrication of g-C₃N₄/Au/C-TiO₂ hollow structures as visible-light-driven Z-scheme photocatalysts with enhanced photocatalytic H₂ evolution, ChemCatChem, 9(2017), No. 19, p. 3752. doi: 10.1002/cctc.201700542
[56]	L.M. Hu, J.T. Yan, C.L. Wang, B. Chai, and J.F. Li, Direct electrospinning method for the construction of Z-scheme TiO₂/g-C₃N₄/RGO ternary heterojunction photocatalysts with remarkably ameliorated photocatalytic performance, Chin. J. Catal., 40(2019), No. 3, p. 458. doi: 10.1016/S1872-2067(18)63181-X
[57]	X.W. Liu, W.Q. Li, R. Hu, et al., Synergistic degradation of acid orange 7 dye by using non-thermal plasma and g-C₃N₄/TiO₂: Performance, degradation pathways and catalytic mechanism, Chemosphere, 249(2020), art. No. 126093. doi: 10.1016/j.chemosphere.2020.126093
[58]	D. Liang, Y.L. Huang, F. Wu, et al., In situ synthesis of g-C₃N₄/TiO₂ with{001}and{101}facets coexposed for water remediation, Appl. Surf. Sci., 487(2019), p. 322. doi: 10.1016/j.apsusc.2019.05.088
[59]	X.J. Wang, W.Y. Yang, F.T. Li, Y.B. Xue, R.H. Liu, and Y.J. Hao, In situ microwave-assisted synthesis of porous N-TiO₂/g-C₃N₄ heterojunctions with enhanced visible-light photocatalytic properties, Ind. Eng. Chem. Res., 52(2013), No. 48, p. 17140. doi: 10.1021/ie402820v
[60]	X.W. Liu, J. Chen, L.F. Yang, et al., 2D/2D g-C₃N₄/TiO₂ with exposed (001) facets Z-Scheme composites accelerating separation of interfacial charge and visible photocatalytic degradation of Rhodamine B, J. Phys. Chem. Solids, 160(2022), art. No. 110339. doi: 10.1016/j.jpcs.2021.110339
[61]	S. Zhou, Y. Liu, J.M. Li, et al., Facile in situ synthesis of graphitic carbon nitride (g-C₃N₄)-N-TiO₂ heterojunction as an efficient photocatalyst for the selective photoreduction of CO₂ to CO, Appl. Catal. B: Environ., 158-159(2014), p. 20. doi: 10.1016/j.apcatb.2014.03.037
[62]	M. Sathish, B. Viswanathan, R.P. Viswanath, and C.S. Gopinath, Synthesis, characterization, electronic structure, and photocatalytic activity of nitrogen-doped TiO₂ nanocatalyst, Chem. Mater., 17(2005), No. 25, p. 6349. doi: 10.1021/cm052047v
[63]	L. Zhou, J.R. Feng, B.C. Qiu, et al., Ultrathin g-C₃N₄ nanosheet with hierarchical pores and desirable energy band for highly efficient H₂O₂ production, Appl. Catal. B: Environ., 267(2020), art. No. 118396. doi: 10.1016/j.apcatb.2019.118396
[64]	C. Yang, X. Liu, J. Liu, et al., Long-lasting photocatalytic activity of trace phosphorus-doped g-C₃N₄/SMSO and its application in antibacterial ceramics, Ecotoxicol. Environ. Saf., 242(2022), art. No. 113951. doi: 10.1016/j.ecoenv.2022.113951
[65]	H.J. Liang, M.C. Yu, J.Y. Guo, et al., A novel vacancy-strengthened Z-scheme g-C₃N₄/Bp/MoS₂ composite for super-efficient visible-light photocatalytic degradation of ciprofloxacin, Sep. Purif. Technol., 272(2021), art. No. 118891. doi: 10.1016/j.seppur.2021.118891
[66]	M.X. Tan, Y. Ma, C.Y. Yu, et al., Boosting photocatalytic hydrogen production via interfacial engineering on 2D ultrathin Z-scheme ZnIn₂S₄/g-C₃N₄ heterojunction, Adv. Funct. Mater., 32(2022), No. 14, art. No. 2111740. doi: 10.1002/adfm.202111740
[67]	Y.T. Yu, W.C. Xu, J.Z. Fang, et al., Soft-template assisted construction of superstructure TiO₂/SiO₂/g-C₃N₄ hybrid as efficient visible-light photocatalysts to degrade berberine in seawater via an adsorption-photocatalysis synergy and mechanism insight, Appl. Catal. B: Environ., 268(2020), art. No. 118751. doi: 10.1016/j.apcatb.2020.118751
[68]	X.N. Hu, Y. Zhang, B.J. Wang, H.J. Li, and W.B. Dong, Novel g-C₃N₄/BiOCl_xI_1−x nanosheets with rich oxygen vacancies for enhanced photocatalytic degradation of organic contaminants under visible and simulated solar light, Appl. Catal. B: Environ., 256(2019), art. No. 117789. doi: 10.1016/j.apcatb.2019.117789
[69]	Y.Y. Wu, X.T. Chen, J.C. Cao, et al., Photocatalytically recovering hydrogen energy from wastewater treatment using MoS₂@TiO₂ with sulfur/oxygen dual-defect, Appl. Catal. B: Environ., 303(2022), art. No. 120878. doi: 10.1016/j.apcatb.2021.120878
[70]	J.S. Yuan, Y. Zhang, X.Y. Zhang, L. Zhao, H.L. Shen, and S.G. Zhang, Template-free synthesis of core–shell Fe₃O₄@MoS₂@mesoporous TiO₂ magnetic photocatalyst for wastewater treatment, Int. J. Miner. Metall. Mater., 30(2023), No. 1, p. 177. doi: 10.1007/s12613-022-2473-9
[71]	C.J. Wang, Y.L. Zhao, H. Xu, et al., Efficient Z-scheme photocatalysts of ultrathin g-C₃N₄-wrapped Au/TiO₂-nanocrystals for enhanced visible-light-driven conversion of CO₂ with H₂O, Appl. Catal. B: Environ., 263(2020), art. No. 118314. doi: 10.1016/j.apcatb.2019.118314
[72]	C. Zhao, Y. Li, H.Y. Chu, et al., Construction of direct Z-scheme Bi₅O₇I/UiO-66-NH₂ heterojunction photocatalysts for enhanced degradation of ciprofloxacin: Mechanism insight, pathway analysis and toxicity evaluation, J. Hazard. Mater., 419(2021), art. No. 126466. doi: 10.1016/j.jhazmat.2021.126466
[73]	Z.F. Hu, D. Shi, G.H. Wang, et al., Carbon dots incorporated in hierarchical macro/mesoporous g-C₃N₄/TiO₂ as an all-solid-state Z-scheme heterojunction for enhancement of photocatalytic H₂ evolution under visible light, Appl. Surf. Sci., 601(2022), art. No. 154167. doi: 10.1016/j.apsusc.2022.154167
[74]	D.T. Zhou, B.B. Yu, Q.L. Chen, et al., Improved visible light photocatalytic activity on Z-scheme g-C₃N₄ decorated TiO₂ nanotube arrays by a simple impregnation method, Mater. Res. Bull., 124(2020), art. No. 110757. doi: 10.1016/j.materresbull.2019.110757
[75]	A. Kumar, M. Khan, J.H. He, and I.M.C. Lo, Visible-light-driven magnetically recyclable terephthalic acid functionalized g-C₃N₄/TiO₂ heterojunction nanophotocatalyst for enhanced degradation of PPCPs, Appl. Catal. B: Environ., 270(2020), art. No. 118898. doi: 10.1016/j.apcatb.2020.118898
[76]	X. Hu, X.J. Hu, Q.Q. Peng, et al., Mechanisms underlying the photocatalytic degradation pathway of ciprofloxacin with heterogeneous TiO₂, Chem. Eng. J., 380(2020), art. No. 122366. doi: 10.1016/j.cej.2019.122366
[77]	D.E. Lee, S. Moru, W.K. Jo, and S. Tonda, Porous g-C₃N₄-encapsulated TiO₂ hollow sphere as a high-performance Z-scheme hybrid for solar-induced photocatalytic abatement of environmentally toxic pharmaceuticals, J. Mater. Sci. Technol., 82(2021), p. 21. doi: 10.1016/j.jmst.2020.10.084
[78]	W.Q. Li, S.Q. Li, Y. Tang, et al., Highly efficient activation of peroxymonosulfate by cobalt sulfide hollow nanospheres for fast ciprofloxacin degradation, J. Hazard. Mater., 389(2020), art. No. 121856. doi: 10.1016/j.jhazmat.2019.121856
[79]	B.S. Li, S.Y. Liu, C. Lai, et al., Unravelling the interfacial charge migration pathway at atomic level in 2D/2D interfacial Schottky heterojunction for visible-light-driven molecular oxygen activation, Appl. Catal. B: Environ., 266(2020), art. No. 118650. doi: 10.1016/j.apcatb.2020.118650
[80]	Y.Q. Lu, C.S. Ding, J. Guo, et al., Highly efficient photodegradation of ciprofloxacin by dual Z-scheme Bi₂MoO₆/GQDs/TiO₂ heterojunction photocatalysts: Mechanism analysis and pathway exploration, J. Alloys Compd., 924(2022), art. No. 166533. doi: 10.1016/j.jallcom.2022.166533