A critical review on prospects and challenges of metal-oxide embedded g-C3N4-based direct Z-scheme photocatalysts for water splitting and environmental remediation

Rong, 2020, N2 photofixation by Z-scheme single-layer g-C3N4/ZnFe2O4 for cleaner ammonia production, Mater. Res. Bull., 127, 10.1016/j.materresbull.2020.110853 Chen, 2016, Facile synthesis of highly efficient graphitic-C3N4/ZnFe2O4 heterostructures enhanced visible-light photocatalysis for spiramycin degradation, J. Photochem. Photobiol. A, 328, 24, 10.1016/j.jphotochem.2016.04.026 Das, 2020, Enhanced photocatalytic activities of polypyrrole sensitized zinc ferrite/graphitic carbon nitride n-n heterojunction towards ciprofloxacin degradation, hydrogen evolution and antibacterial studies, J. Colloid Interface Sci., 561, 551, 10.1016/j.jcis.2019.11.030 Fajrina, 2019, A critical review in strategies to improve photocatalytic water splitting towards hydrogen production, Int. J. Hydrog. Energy, 44, 540, 10.1016/j.ijhydene.2018.10.200 Palanivel, 2019, Rational design of ZnFe2O4/g-C3N4 nanocomposite for enhanced photo-Fenton reaction and supercapacitor performance, Appl. Surf. Sci., 498, 10.1016/j.apsusc.2019.143807 Sahoo, 2020, Fe3O4 nanoparticles functionalized GO/g-C3N4 nanocomposite: an efficient magnetic nanoadsorbent for adsorptive removal of organic pollutants, Mater. Chem. Phys., 244, 10.1016/j.matchemphys.2020.122710 Lam, 2020, Mainstream avenues for boosting graphitic carbon nitride efficiency: towards enhanced solar light-driven photocatalytic hydrogen production and environmental remediation, J. Mater. Chem. A, 8, 10571, 10.1039/D0TA02582H Renukadevi, 2020, A one-pot microwave irradiation route to synthesis of CoFe2O4-g-C3N4 heterojunction catalysts for high visible light photocatalytic activity: Exploration of efficiency and stability, Diamond Relat. Mater., 109, 10.1016/j.diamond.2020.108012 Borthakur, 2019, ZnFe2O4@g-C3N4 nanocomposites: An efficient catalyst for Fenton-like photodegradation of environmentally pollutant Rhodamine B, J. Environ. Chem. Eng., 7, 10.1016/j.jece.2019.103035 Fujishima, 1972, Electrochemical photolysis of water at a semiconductor electrode, Nature, 238, 37, 10.1038/238037a0 Pawar, 2014, Hybrid photocatalysts using graphitic carbon nitride/cadmium sulfide/reduced graphene oxide (g-C3N4/CdS/RGO) for superior photodegradation of organic pollutants under UV and visible light, Dalton Trans., 43, 12514, 10.1039/C4DT01278J Wen, 2017, A review on g-C3N4 -based photocatalysts, Appl. Surf. Sci., 391, 72, 10.1016/j.apsusc.2016.07.030 Saravanan, 2017, Basic principles, mechanism, and challenges of photocatalysis, 19 Li, 2021, A review of material aspects in developing direct Z-scheme photocatalysts, Mater. Today, 47, 75, 10.1016/j.mattod.2021.02.017 Das, 2021, Recent advancements of g-C3N4-based magnetic photocatalysts towards the degradation of organic pollutants: a review, Nanotechnology, 33 L. Jiang, Doping of graphitic carbon nitride for photocatalysis: a reveiw, (2017) 19. A. Sudhaik, Magnetically recoverable graphitic carbon nitride and NiFe2O4 based magnetic photocatalyst for degradation of oxytetracycline antibiotic in simulated wastewater under solar light, (n.d.) 30. Akhundi, 2021, Correction: facile preparation of novel quaternary g-C3N4/Fe3O4/AgI/Bi2S3 nanocomposites: magnetically separable visible-light-driven photocatalysts with significantly enhanced activity, RSC Adv., 11, 22148, 10.1039/D1RA90125G Wang, 2020, Recent progress in g-C3N4 quantum dots: synthesis, properties and applications in photocatalytic degradation of organic pollutants, J. Mater. Chem. A, 8, 485, 10.1039/C9TA11368A Długosz, 2020, Synthesis of Fe3O4/ZnO nanoparticles and their application for the photodegradation of anionic and cationic dyes, Int. J. Environ. Sci. Technol. S.L. Lee, C.J. Chang, Recent progress on metal sulfide composite nanomaterials for photocatalytic hydrogen production, (2019) 25. M.J. Jacinto, Magnetic materials for photocatalytic applications–a review, (2020) 14. Singh, 2019, Systematic review on applicability of magnetic iron oxides–integrated photocatalysts for degradation of organic pollutants in water, Mater. Today Chem., 14 Wang, 2009, A metal-free polymeric photocatalyst for hydrogen production from water under visible light, Nat. Mater., 8, 76, 10.1038/nmat2317 Basharnavaz, 2018, Pt-embedded graphitic carbon nitrides as excellent adsorbents for HCN removal: a DFT study, Appl. Surf. Sci., 456, 882, 10.1016/j.apsusc.2018.06.159 Z. Ahmadi, M. Zakeri, A. Habibi-Yangjeh, M.S. Asl, A novel ZrB2–C3N4 composite with improved mechanical properties, (2019). 10.1016/J.CERAMINT.2019.07.144. Wang, 2017, Recent Advances of graphitic carbon nitride-based structures and applications in catalyst, sensing, imaging, and LEDs, Nano-Micro Lett., 9, 47, 10.1007/s40820-017-0148-2 Pattnaik, 2019, Facile synthesis of exfoliated graphitic carbon nitride for photocatalytic degradation of ciprofloxacin under solar irradiation, J. Mater. Sci., 54, 10.1007/s10853-018-03266-x Shen, 2019, Co1.4Ni0.6P cocatalysts modified metallic carbon black/g-C3N4 nanosheet Schottky heterojunctions for active and durable photocatalytic H2 production, Appl. Surf. Sci., 466, 393, 10.1016/j.apsusc.2018.10.033 Chai, 2020, In situ fabrication of CdMoO4/g-C3N4 composites with improved charge separation and photocatalytic activity under visible light irradiation, Chin. J. Catal., 41, 170, 10.1016/S1872-2067(19)63383-8 Sahoo, 2021, Facile construction of CoWO4 modified g-C3N4 nanocomposites with enhanced photocatalytic activity under visible light irradiation, Mater. Today Proc., 35, 193, 10.1016/j.matpr.2020.04.246 Cheng, 2016, Facile construction of CuFe2O4/g-C3N4 photocatalyst for enhanced visible-light hydrogen evolution, RSC Adv., 6, 18990, 10.1039/C5RA27221A J. Rashid, N. Parveen, T. ul Haq, A. Iqbal, S.H. Talib, S.U. Awan, N. Hussain, M. Zaheer, g-C3N4/CeO2/Fe3O4 ternary composite as an efficient bifunctional catalyst for overall water splitting, ChemCatChem. 10 (2022) 5587. R. Shen, In-situ construction of metallic Ni3C@Ni core–shell cocatalysts over g-C3N4 nanosheets for shell-thickness-dependent photocatalytic H2 production, (2021) 12. Zarezadeh, 2019, Fabrication of novel ZnO/BiOBr/C-Dots nanocomposites with considerable photocatalytic performances in removal of organic pollutants under visible light, Adv. Powder Technol., 13 Li, 2021, Two-dimensional sulfur- and chlorine-codoped g-C3N4/CdSe-amine heterostructures nanocomposite with effective interfacial charge transfer and mechanism insight, Appl. Catal. B, 280, 10.1016/j.apcatb.2020.119452 J. Arulraj, M. Mathew, Photocatalytic applications of transition metal and metal oxide nanoparticles, 4 (2019) 13. M.S.S. Danish, L.L. Estrella, I.M.A. Alemaida, A. Lisin, N. Moiseev, M. Ahmadi, M. Nazari, M. Wali, H. Zaheb, T. Senjyu, Photocatalytic applications of metal oxides for sustainable environmental remediation, (2021) 25. X. Zhu, X. Tian, R. Yin, Q. Luo, J. An, X. Li, D. Wang, A strategy for preparation of Fe2O3/g-C3N4 composites with efficient visible-light photocatalytic activity, (n.d.) 12. Xu, 2018, Direct Z-scheme photocatalysts: principles, synthesis, and applications, Mater. Today, 21, 1042, 10.1016/j.mattod.2018.04.008 J. Wang, X. Zuo, W. Cai, J. Sun, X. Ge, H. Zhao, Facile fabrication of direct solid-state Z-scheme g-C3N4/Fe2O3 heterojunction: a cost-effective photocatalyst with high efficiency for aqueous organic pollutant degradation, (n.d.) 11. R. Parvari, α-Fe2O3/Ag/g-C3N4 core-discontinuous shell nanocomposite as an indirect Z-scheme photocatalyst for degradation of ethylbenzene in the air under white LEDs irradiation, (n.d.) 15. Sumathi, 2019, A facile microwave stimulated g-C3N4/α-Fe2O3 hybrid photocatalyst with superior photocatalytic activity and attractive cycling stability, J. Mater. Sci., 9 Low, 2017, A review of direct Z-scheme photocatalysts, Small Methods, 1, 10.1002/smtd.201700080 Mishra, 2021, Orienting Z scheme charge transfer in graphitic carbon nitride-based systems for photocatalytic energy and environmental applications, J. Mater. Chem. A, 9, 10039, 10.1039/D1TA00704A Li, 2020, A mini review on bismuth-based Z-scheme photocatalysts, Materials, 13, 5057, 10.3390/ma13225057 Li, 2016, Z-scheme photocatalytic systems for promoting photocatalytic performance: recent progress and future challenges, Adv. Sci., 3, 10.1002/advs.201500389 Zhou, 2014, AllSolidState Zscheme photocatalytic systems, Adv. Mater., 16 Li, 2022, Review on g-C3N4-based S-scheme heterojunction photocatalysts, J. Mater. Sci. Technol., 125, 128, 10.1016/j.jmst.2022.02.035 J. Fu, Ultrathin 2D/2D WO3/g-C3N4 step-scheme H2-production photocatalyst, (2019) 10. Q. Xu, S-scheme heterojunction photocatalyst, (n.d.) 17. F. Xu, Unique S-scheme heterojunctions in self-assembled TiO2/CsPbBr3 hybrids for CO2 photoreduction, (n.d.) 9. Wang, 2019, Facile synthesis of a novel WO3/Ag2MoO4 particles-on-plate staggered type II heterojunction with improved visible-light photocatalytic activity in removing environmental pollutants, RSC Adv., 10 Hu, 2020, Facile synthesis of Z-scheme composite of TiO2 nanorod/g-C3N4 nanosheet efficient for photocatalytic degradation of ciprofloxacin, J. Clean. Prod., 9 Jia, 2020, MOF-derived the direct Z-scheme g-C3N4/TiO2 with enhanced visible photocatalytic activity, J. Sol Gel Sci. Technol., 93, 123, 10.1007/s10971-019-05172-3 M. Liu, S. Wei, W. Chen, H. Dang, L. Gao, X. Li, L. Mao, Construction of direct Z-scheme g-C3N4/TiO2 nanorod composites for promoting photocatalytic activity, (n.d.) 7. Lin, 2021, Enhanced optical absorption and photocatalytic water splitting of g-C3N4/TiO2 heterostructure through C&B codoping: a hybrid DFT study, Int. J. Hydrog. Energy, 46, 9417, 10.1016/j.ijhydene.2020.12.114 Liu, 2016, A new understanding of the photocatalytic mechanism of the direct Z-scheme g-C3N4 /TiO2 heterostructure, Phys. Chem. Chem. Phys., 18, 31175, 10.1039/C6CP06147H N. Li, Y. Tian, J. Zhao, J. Zhang, W. Zuo, L. Kong, H. Cui, Z-scheme 2D/3D g-C3N4@ZnO with enhanced photocatalytic activity for cephalexin oxidation under solar light, (n.d.) 50. Singh, 2019, Degradation of toxic industrial dyes using SnO2/g-C3N4 nanocomposites_ Role of mass ratio on photocatalytic activity, J. Photochem., 8 Huang, 2018, In-situ loading of (BiO)2CO3 on g-C3N4 with promoted solar-driven photocatalytic performance originated from a direct Z-scheme mechanism, Mater. Sci. Semicond. Process., 82, 97, 10.1016/j.mssp.2018.03.036 Zhang, 2020, Influence of BiOIO3 morphology on the photocatalytic efficiency of Z-scheme BiOIO3/g-C3N4 heterojunctioned composite for Hg0 removal, J. Colloid Interface Sci., 14 Wan, 2017, Novel visible-light-driven Z-scheme Bi12GeO20/g-C3N4 photocatalyst: Oxygen-induced pathway of organic pollutants degradation and proton assisted electron transfer mechanism of Cr(VI) reduction, Appl. Catal. B, 207, 17, 10.1016/j.apcatb.2017.02.014 Wang, 2019, 3D/2D direct Z-scheme heterojunctions of hierarchical TiO2 microflowers/g-C3N4 nanosheets with enhanced charge carrier separation for photocatalytic H2 evolution, Carbon, 149, 618, 10.1016/j.carbon.2019.04.088 Shi, 2021, MoO3/g-C3N4 Z-scheme (S-scheme) system derived from MoS2/melamine dual precursors for enhanced photocatalytic H2 evolution driven by visible light, Int. J. Hydrog. Energy, 46, 2927, 10.1016/j.ijhydene.2020.04.216 Ma, 2018, Potassium ions intercalated into g-C3N4 -modified TiO2 nanobelts for the enhancement of photocatalytic hydrogen evolution activity under visible-light irradiation, Nanotechnology, 29, 10.1088/1361-6528/aab564 Liu, 2021, Z-scheme N-doped K4Nb6O17/g-C3N4 heterojunction with superior visible-light-driven photocatalytic activity for organic pollutant removal and hydrogen production, Chin. J. Catal., 42, 164, 10.1016/S1872-2067(20)63608-7 Yang, 2018, WS2 and C-TiO2 nanorods acting as effective charge separators on g-C3N4 to boost visible-light activated hydrogen production from seawater, ChemSusChem, 11, 4077, 10.1002/cssc.201801819 Truc, 2019, The advanced photocatalytic degradation of atrazine by direct Z-scheme Cu doped ZnO/g-C3N4, Appl. Surf. Sci., 8 Zhu, 2018, Fabrication of a Z-Scheme g-C3N4/Fe-TiO2 Photocatalytic Composite with Enhanced Photocatalytic Activity under Visible Light Irradiation, Catalysts, 8, 112, 10.3390/catal8030112 Kong, 2018, Ti3+ defect mediated g-C3N4/TiO2 Z-scheme system for enhanced photocatalytic redox performance, Appl. Surf. Sci., 448, 288, 10.1016/j.apsusc.2018.04.011 Fang, 2019, 0D/2D Z-scheme heterojunctions of g-C3N4 quantum dots/ZnO nanosheets as a highly efficient visible-light photocatalyst, Adv. Powder Technol., 8 Xing, 2017, Z-scheme BCN-TiO2 nanocomposites with oxygen vacancy for high efficiency visible light driven hydrogen production, Int. J. Hydrog. Energy, 42, 28434, 10.1016/j.ijhydene.2017.09.125 Huang, 2019, One-pot hydrothermal synthesis of TiO2/RCN heterojunction photocatalyst for production of hydrogen and rhodamine B degradation, Appl. Surf. Sci., 493, 202, 10.1016/j.apsusc.2019.07.013 Yang, 2019, G-C3N4 nanosheets coupled with TiO2 nanosheets as 2D/2D heterojunction photocatalysts toward high photocatalytic activity for hydrogen production, Catal. Lett., 149, 2930, 10.1007/s10562-019-02805-8 Tan, 2018, One-step synthesis of nanostructured g-C3N4/TiO2 composite for highly enhanced visible-light photocatalytic H2 evolution, Appl. Catal. B, 230, 260, 10.1016/j.apcatb.2018.02.056 Pan, 2018, The enhanced photocatalytic hydrogen production of the fusiform g-C3N4 modification CaTiO3 nano-heterojunction, Int. J. Hydrog. Energy, 43, 19019, 10.1016/j.ijhydene.2018.08.102 Yang, 2019, Visible light-driven photocatalytic H 2 generation and mechanism insights into Bi2O2CO3 /G-C3N4 Z-scheme photocatalyst, J. Phys. Chem. C, 123, 4795, 10.1021/acs.jpcc.8b10604 Tan, 2020, Facile approach for Z-scheme type Pt/g-C3N4/SrTiO3 heterojunction semiconductor synthesis via low-temperature process for simultaneous dyes degradation and hydrogen production, Int. J. Hydrog. Energy, 45, 13330, 10.1016/j.ijhydene.2020.03.034 Bakr, 2019, Synthesis and characterization of Z-scheme α-Fe2O3 NTs/ruptured tubular g-C3N4 for enhanced photoelectrochemical water oxidation, Sol. Energy, 193, 403, 10.1016/j.solener.2019.09.052 Zhao, 2020, Enhanced charge separation and transfer of Fe2O3 @nitrogen-rich carbon nitride tubes for photocatalytic water splitting, Energy Technol., 8, 10.1002/ente.202000108 Li, 2017, Z-scheme electronic transfer of quantum-sized α-Fe2O3 modified g-C3N4 hybrids for enhanced photocatalytic hydrogen production, Int. J. Hydrog. Energy, 42, 28327, 10.1016/j.ijhydene.2017.09.137 H. Shao, P. Yao, Y. Chen, Y. Yao, G. Li, X. Liao, Ball-milling method encapsulated a-Fe2O3 into g-C3N4 as efficient and stable photo-catalysts, (2021) 9. C. Li, S. Yu, H. Che, X. Zhang, J. Han, Y. Mao, Y. Wang, C. Liu, H. Dong, Fabrication of Z-scheme heterojunction by anchoring mesoporous γ-Fe2O3 nanospheres on g-C3N4 for degrading tetracycline hydrochloride in water, (n.d.) 47. Kang, 2018, Low temperature fabrication of Fe2O3 nanorod film coated with ultra-thin g-C3N4 for a direct z-scheme exerting photocatalytic activities, RSC Adv., 8, 33600, 10.1039/C8RA04499F Katsumata, 2014, Z-scheme photocatalytic hydrogen production over WO3 /g-C3N4 composite photocatalysts, RSC Adv., 4, 21405, 10.1039/C4RA02511C Cheng, 2017, WO3 /g-C3N4 composites: one-pot preparation and enhanced photocatalytic H2 production under visible-light irradiation, Nanotechnology, 28, 10.1088/1361-6528/aa651a Ping, 2014, Optimizing the band edges of tungsten trioxide for water oxidation: a first-principles study, J. Phys. Chem. C, 118, 6019, 10.1021/jp410497f Ta, 2021, Photoelectrochemical stability of WO3/Mo-doped BiVO4 heterojunctions on different conductive substrates in acidic and neutral media, Appl. Surf. Sci., 548, 10.1016/j.apsusc.2021.149251 Knöppel, 2021, Photocorrosion of WO3 Photoanodes in different electrolytes, ACS Phys. Chem Au., 1, 6, 10.1021/acsphyschemau.1c00004 Bembibre, 2022, Visible-light driven sonophotocatalytic removal of tetracycline using Ca-doped ZnO nanoparticles, Chem. Eng. J., 427, 10.1016/j.cej.2021.132006 Parvin, 2022, Influence of morphology on photoanodic behaviour of WO3 films in chloride and sulphate electrolytes, Electrochim. Acta, 403, 10.1016/j.electacta.2021.139710 T. Xiao, In situ construction of hierarchical WO3/g-C3N4 composite hollow microspheres as a Z-Scheme photocatalyst for the degradation of antibiotics, (n.d.) 34. Zhang, 2021, Robust Z-scheme g-C3N4/WO3 heterojunction photocatalysts with morphology control of WO3 for efficient degradation of phenolic pollutants, Sep. Purif. Technol., 16 Meng, 2021, Acid-induced molecule self-assembly synthesis of Z-scheme WO3/g-C3N4 heterojunctions for robust photocatalysis against phenolic pollutants, Chem. Eng. J., 17 F. Bairamis, I. Konstantinou, WO3 fibers/g-C3N4 Z-scheme heterostructure photocatalysts for simultaneous oxidation/reduction of phenol/Cr (VI) in aquatic media, (2021) 13. Shafawi, 2020, Bi2O3 particles decorated on porous g-C3N4 sheets: enhanced photocatalytic activity through a direct Z-scheme mechanism for degradation of Reactive Black 5 under UV–vis light, J. Photochem. Photobiol. A, 389, 10.1016/j.jphotochem.2019.112289 Zhao, 2017, Preparation of direct Z-scheme Bi2Sn2O7/g-C3N4 composite with enhanced photocatalytic performance, J. Photochem. Photobiol. A, 335, 130, 10.1016/j.jphotochem.2016.11.011 X. Zhang, M. Li, C. Liu, Z. Zhang, F. Zhang, Q. Liu, Enhanced the efficiency of photocatalytic degradation of methylene blue by construction of Z-scheme g-C3N4/BiVO4 heterojunction, (2021) 10. Chen, 2015, In situ fabrication of novel Z-scheme Bi2WO6 quantum dots/g-C3N4 ultrathin nanosheets heterostructures with improved photocatalytic activity, Appl. Surf. Sci., 355, 379, 10.1016/j.apsusc.2015.07.111 Xia, 2018, Designing visible-light-driven Z-scheme catalyst 2D g-C3N4/Bi2MoO6: enhanced photodegradation activity of organic pollutants, Phys. Status Solidi A, 8 Li, 2020, Novel rugby-like g-C3N4/BiVO4 core/shell Z-scheme composites prepared T via low-temperature hydrothermal method for enhanced photocatalytic performance, Sep. Purif. Technol., 10 Murugan, 2019, Enhanced charge transfer process of bismuth vanadate interleaved graphitic carbon nitride nanohybrids in mediator-free direct Z scheme photoelectrocatalytic water splitting, ChemistrySelect, 4, 4653, 10.1002/slct.201900732 Chen, 2018, In-situ construction of direct Z-scheme Bi2WO6/g-C3N4 composites with remarkably promoted solar-driven photocatalytic activity, Mater. Chem. Phys., 9 Guo, 2018, 2D/2D Z-scheme Bi2WO6/Porous-g-C3N4 with synergy of adsorption and visible-light-driven photodegradation, Appl. Surf. Sci., 447, 125, 10.1016/j.apsusc.2018.03.080 Huo, 2019, All-solid-state artificial Z-scheme porous g-C3N4/Sn2S3-DETA heterostructure photocatalyst with enhanced performance in photocatalytic CO2 reduction, Appl. Catal. B, 241, 528, 10.1016/j.apcatb.2018.09.073 Huo, 2021, Efficient interfacial charge transfer of 2D/2D porous carbon nitride/bismuth oxychloride step-scheme heterojunction for boosted solar-driven CO2 reduction, J Colloid Interface Sci., 585, 684, 10.1016/j.jcis.2020.10.048 Mei, 2020, Step-scheme porous g-C3N4/Zn0.2Cd0.8S-DETA composites for efficient and stable photocatalytic H2 production, Chin. J. Catal., 41, 41, 10.1016/S1872-2067(19)63389-9 Raeisi-Kheirabadi, 2020, A Z-scheme g-C3N4/Ag3PO4 nanocomposite: Its photocatalytic activity and capability for water splitting, Int. J. Hydrog. Energy, 45, 33381, 10.1016/j.ijhydene.2020.09.028 Al-Zaqri, 2020, Construction of novel direct Z-scheme AgIO4-g-C3N4 heterojunction for photocatalytic hydrogen production and photodegradation of fluorescein dye, Diamond Relat. Mater., 109, 10.1016/j.diamond.2020.108071 Jin, 2019, Z-scheme mpg-C3N4/Ag6Si2O7 heterojunction for highly efficient photocatalytic degradation of organic pollutants under visible light, J. Alloys Compd., 803, 834, 10.1016/j.jallcom.2019.06.350 Wang, 2019, Holey g-C3N4 nanosheet wrapped Ag3PO4 photocatalyst and its visible-light photocatalytic performance, Sol. Energy, 191, 70, 10.1016/j.solener.2019.08.071 J. Zhang, Facile and green synthesis of novel porous g-C3N4/Ag3PO4 composite with enhanced visible light photocatalysis, (n.d.) 8. She, 2017, High efficiency photocatalytic water splitting using 2D α-Fe2O3 /g-C3N4 Z-scheme catalysts, Adv. Energy Mater., 7, 10.1002/aenm.201700025 Xu, 2018, Constructing 2D/2D Fe2O3 /g-C3N4 direct Z-scheme photocatalysts with enhanced H2 generation performance, Sol. RRL., 2, 10.1002/solr.201800006 Han, 2018, WO3/g-C3N4 two-dimensional composites for visible-light driven photocatalytic hydrogen production, Int. J. Hydrog. Energy, 43, 4845, 10.1016/j.ijhydene.2018.01.117 Yu, 2017, Direct Z-scheme g-C3N4/WO3 photocatalyst with atomically defined junction for H2 production, Appl. Catal. B, 219, 693, 10.1016/j.apcatb.2017.08.018 Li, 2020, Exfoliated, mesoporous W18O49/g-C3N4 composites for efficient photocatalytic H2 evolution, Solid State Sci., 106, 10.1016/j.solidstatesciences.2020.106298 Huang, 2021, Construction of 1D/2D W18O49/Porous g-C3N4 S-scheme heterojunction with enhanced photocatalytic H2 evolution, Acta Phys. Chim. Sin., 0, 10.3866/PKU.WHXB202108028 Zhang, 2018, Facile synthesis of high quality Z-scheme W18O49 nanowire-g-C3N4 photocatalyst for the enhanced visible light-driven photocatalytic hydrogen evolution, J. Alloys Compd., 764, 1, 10.1016/j.jallcom.2018.06.045 Huang, 2017, Switching charge transfer of C3N4/W18O49 from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution, Nano Energy (Print), 308, 10.1016/j.nanoen.2017.08.032 Wu, 2018, Decoration of mesoporous Co3O4 nanospheres assembled by monocrystal nanodots on g-C3N4 to construct Z-scheme system for improving photocatalytic performance, Appl. Surf. Sci., 440, 308, 10.1016/j.apsusc.2018.01.134 Liu, 2019, In situ growing of CoO nanoparticles on g-C3 N4 composites with highly improved photocatalytic activity for hydrogen evolution, R. Soc. Open Sci., 6, 10.1098/rsos.190433 Chang, 2019, Highly efficient H2 production over NiCo2O4 decorated g-C3N4 by photocatalytic water reduction, Chem. Eng. J., 362, 392, 10.1016/j.cej.2019.01.021 Ye, 2016, Fabrication of CoTiO3 /g-C3 N4 hybrid photocatalysts with enhanced H 2 evolution: Z-scheme photocatalytic mechanism insight, ACS Appl. Mater. Interfaces., 8, 13879, 10.1021/acsami.6b01850 Wang, 2020, Z-scheme LaCoO 3 /g-C 3 N 4 for efficient full-spectrum light-simulated solar photocatalytic hydrogen generation, ACS Omega, 5, 30373, 10.1021/acsomega.0c03318 Jin, 2019, One-step impregnation method to prepare direct Z-scheme LaCoO3/g-C3N4 T heterojunction photocatalysts for phenol degradation under visible light, Appl. Surf. Sci., 11 Guo, 2019, A novel Z-scheme g- C3N4/LaCoO3 heterojunction with enhanced photocatalytic activity in degradation of tetracycline hydrochloride, Catal. Commun., 122, 63, 10.1016/j.catcom.2019.01.022 Jin, 2018, Boosting visible light photocatalytic performance of g-C3N4 nanosheets by combining with LaFeO3 nanoparticles, Mater. Res. Bull., 102, 353, 10.1016/j.materresbull.2018.02.057 Sepahvand, 2019, Photocatalytic overall water splitting by Z-scheme g-C3N4/BiFeO3 heterojunction, Int. J. Hydrog. Energy, 44, 23658, 10.1016/j.ijhydene.2019.07.078 Jo, 2020, Magnetically responsive SnFe2O4/g-C3N4 hybrid photocatalysts with remarkable visible-light-induced performance for degradation of environmentally hazardous substances and sustainable hydrogen production, Appl. Surf. Sci., 506, 10.1016/j.apsusc.2019.144939 Kim, 2019, Application of a photostable silver-assisted Z-scheme NiTiO3 nanorod/g-C3N4 nanocomposite for efficient hydrogen generation, Int. J. Hydrog. Energy, 44, 801, 10.1016/j.ijhydene.2018.11.014 P. Xia, B. Zhu, B. Cheng, J. Yu, J. Xu, 2D/2D g-C3N4/MnO2 nanocomposite as a direct Z-scheme photocatalyst for enhanced photocatalytic activity, (n.d.) 34. Zhang, 2020, Porous Z-scheme MnO2/Mn-modified alkalinized g-C3N4 heterojunction with excellent Fenton-like photocatalytic activity for efficient degradation of pharmaceutical pollutants, Sep. Purif. Technol., 10 Wang, 2019, Holey g-C3N4 nanosheet wrapped Ag3PO4 photocatalyst and its visible-light photocatalytic performance, Sol. Energy, 8 Z. Huang, X. Zeng, K. Li, S. Gao, Q. Wang, J. Lu, Z-scheme NiTiO3/g-C3N4 heterojunctions with enhanced photoelectrochemical and photocatalytic performances under visible LED light irradiation, (n.d.) 17. He, 2015, Z-scheme SnO2−x/g-C3N4 composite as an efficient photocatalyst for dye degradation and photocatalytic CO2 reduction, Sol. Energy Mater., 10 Jing, 2021, Engineering of g-C3N4 nanoparticles/WO3 hollow microspheres photocatalyst with Z-scheme heterostructure for boosting tetracycline hydrochloride degradation, Sep. Purif. Technol., 14 Sun, 2017, Enhanced photocatalytic oxidation of toluene with a coral-like direct Z-scheme BiVO4/g-C3N4 photocatalyst, J. Alloys Compd., 8 X. Wei, Facile ball-milling synthesis of CeO2/g-C3N4 Z-scheme heterojunction for synergistic adsorption and photodegradation of methylene blue: characteristics, kinetics, models, and mechanisms, (n.d.) 33. Zhao, 2021, A novel Z-scheme CeO2/g-C3N4 heterojunction photocatalyst for degradation of Bisphenol A and hydrogen evolution and insight of the photocatalysis mechanism, J. Mater. Sci., 12 Qiao, 2018, Facile in situ construction of mediator- free direct Z-scheme g-C3N4/CeO2 heterojunctions with highly efficient photocatalytic activity, Appl. Phys., 13 Zhu, 2021, Z-scheme 2D/2D g-C3N4/Sn3O4 heterojunction for enhanced visible-light photocatalytic H2 evolution and degradation of ciprofloxacin, Mater. Sci. Semicond. Process., 12 Yang, 2018, A direct Z-scheme van der waals heterojunction (WO 3 ·H 2 O/g-C3N4) for high efficient overall water splitting under visible-light, Sol. RRL., 2, 10.1002/solr.201800148 Chen, 2019, Fabrication of hierarchical sheet-on-sheet WO3/g-C3N4 composites with enhanced photocatalytic activity, J. Alloys Compd., 777, 325, 10.1016/j.jallcom.2018.10.404 Zhang, 2021, Dopant and defect doubly modified CeO2 /g-C3 N4 nanosheets as 0D/2D Z-scheme heterojunctions for photocatalytic hydrogen evolution: experimental and density functional theory studies, ACS Sustain. Chem. Eng., 9, 11479, 10.1021/acssuschemeng.1c03683 Liu, 2019, Facile synthesis of CeO2/g-C3N4 nanocomposites with significantly improved visible-light photocatalytic activity for hydrogen evolution, Int. J. Hydrog. Energy, 44, 16154, 10.1016/j.ijhydene.2019.05.042 Vattikuti, 2018, Synthesis of vanadium-pentoxide-supported graphitic carbon nitride heterostructure and studied their hydrogen evolution activity under solar light, J. Mater. Sci. Mater. Electron., 29, 18760, 10.1007/s10854-018-0001-5 Gu, 2021, Facile fabrication of sulfur-doped Cu2O and g-C3N4 with Z-scheme structure for enhanced photocatalytic water splitting performance, Mater. Chem. Phys., 266, 10.1016/j.matchemphys.2021.124542 Mishra, 2019, Facile construction of a novel NiFe2 O4 @P-doped g-C3N4 nanocomposite with enhanced visible-light-driven photocatalytic activity, Nanoscale Adv., 1, 1864, 10.1039/C9NA00018F Wei, 2021, Double Z-scheme system of α-SnWO4/UiO-66(NH2)/g-C3N4 ternary heterojunction with enhanced photocatalytic performance for ibuprofen degradation and H2 evolution, J. Alloys Compd., 885, 10.1016/j.jallcom.2021.160984 Rajendran, 2022, Designing of TiO2/α-Fe2O3 coupled g-C3N4 magnetic heterostructure composite for efficient Z-scheme photo-degradation process under visible light exposures, J. Alloys Compd., 13 M. Moradi, CuO and ZnO co-anchored on g-C3N4 nanosheets as an affordable double Z-scheme nanocomposite for photocatalytic decontamination of amoxicillin, (2021) 16. Jiang, 2018, In-situ synthesis of direct solid-state dual Z-scheme WO3/g-C3N4/Bi2O3 photocatalyst for the degradation of refractory pollutant, Appl. Catal. B, 227, 376, 10.1016/j.apcatb.2018.01.042 Jiao, 2020, Double Z-scheme photocatalyst C3N4 nanotube/N-doped carbon dots/Ni2P with enhanced visible-light photocatalytic activity for hydrogen generation, Appl. Surf. Sci., 534, 10.1016/j.apsusc.2020.147603 Devarayapalli, 2020, Microwave synthesized nano-photosensitizer of CdS QD/MoO3–OV/g–C3N4 heterojunction catalyst for hydrogen evolution under full-spectrum light, Ceram. Int., 46, 28467, 10.1016/j.ceramint.2020.08.004 Shende, 2021, Exciton dissociation on double Z-scheme heterojunction for photocatalytic application, ChemistrySelect, 6, 6707, 10.1002/slct.202101556 Ghafoor, 2019, TiO2 nanofibers embedded with g-C3N4 nanosheets and decorated with Ag nanoparticles as Z-scheme photocatalysts for environmental remediation, J. Environ. Chem. Eng., 7, 10.1016/j.jece.2019.103452 Ibrahim, 2021, Visible-light-driven photocatalytic performance of a Z-scheme based TiO2/WO3/g-C3N4 ternary heterojunctions, Mol. Catal., 14 G. Alnaggar, Sunlight-driven activation of peroxymonosulfate by microwave synthesized ternary MoO3/Bi2O3/g-C3N4 heterostructures for boosting tetracycline hydrochloride degradation, (2021) 11. Li, 2016, Improved photoelectrochemical performance of Z-scheme g-C3N4/Bi2O3/BiPO4 heterostructure and degradation property, Appl. Surf. Sci., 385, 34, 10.1016/j.apsusc.2016.05.065 Long, 2021, Dielectric barrier discharge plasma-assisted modification of g-C3N4/Ag2O/TiO2-NRs composite enhanced photoelectrocatalytic activity, J. Environ. Sci., 104, 113, 10.1016/j.jes.2020.11.029 Zhu, 2020, High visible light response Z-scheme Ag3PO4/g-C3N4 / ZnO composite photocatalyst for efficient degradation of tetracycline hydrochloride: preparation, properties and mechanism, J. Alloys Compd., 840, 10.1016/j.jallcom.2020.155714 Li, 2019, Novel g-C3N4/h′ZnTiO3-a′TiO2 direct Z-scheme heterojunction with significantly enhanced visible-light photocatalytic activity, J. Alloys Compd., 774, 768, 10.1016/j.jallcom.2018.10.034 Fang, 2021, Enhanced photocatalytic characteristics and low selectivity of a novel Z-scheme TiO2/g − C3N4/Bi2WO6 heterojunction under visible light, Mater. Sci. Semicond. Process., 8 Synthesis and characterization of CeO2/Bi2O3/gC3N4 ternary Z-scheme nanocomposite, (n.d.) 11. Lv, 2020, MOF-derived CoFe2O4/Fe2O3 embedded in g-C3N4 as high-efficient Z-scheme photocatalysts for enhanced degradation of emerging organic pollutants in the presence of persulfate, Sep. Purif. Technol., 253, 10.1016/j.seppur.2020.117413 He, 2017, Enhanced visible light photocatalytic H2 production over Z-scheme g-C3N4 nansheets/WO3 nanorods nanocomposites loaded with Ni(OH) x cocatalysts, Chin. J. Catal., 38, 240, 10.1016/S1872-2067(17)62759-1 Lv, 2020, Efficient photocatalytic hydrogen production using an NH4TiOF3/TiO2/g-C3N4 composite with a 3D camellia-like Z-scheme heterojunction structure, Ceram. Int., 46, 26689, 10.1016/j.ceramint.2020.07.141 Sun, 2020, Fabrication of hollow g-C3N4@α-Fe2O3/Co-Pi heterojunction spheres with enhanced visible-light photocatalytic water splitting activity, Int. J. Hydrog. Energy, 45, 2840, 10.1016/j.ijhydene.2019.11.182