Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Highly efficient Z-scheme g-C3N4/ZnO photocatalysts constructed by co-melting-recrystallizing mixed precursors for wastewater treatment


Due to the powerful functions of photocatalytic technology in degrading organic pollutants by using sunlight, the development of photocatalytic materials with visible light response has received great attention in order to meet the requirements of energy saving and emission reduction. Herein, we synthesize a new type of composite photocatalyst composed of graphite-like C3N4 and ZnO by co-melting-recrystallizing the precursors of two pure catalysts at 600 °C under air atmosphere. The composites present an enhanced photocatalytic activity under visible light irradiation, the kinetic constant of Methyl Orange (MO) degradation with g-C3N4/ZnO is 2.89 and 8.23 times those of the pure g-C3N4 and ZnO, respectively. Moreover, the high stability of the photocatalyst was reflected in the photodegradation of MO. The ZnO was successfully incorporated into the lattice of g-C3N4, and a Zn–N bond was formed, which resulted in an enhanced charge transfer efficiency in composites. Therefore, the low separation efficiency of photogenerated electrons–hole pairs existed in a single catalyst was well solved after g-C3N4 was combined with ZnO. The adjustment of raw material ratio shows great influence on the photocatalytic activity, and the optimum synergetic effect of the composite catalyst was found at a weight ratio of 1/30 of ZnO precursor to g-C3N4 precursor. We concluded that the photocatalytic system formed by g-C3N4 and ZnO should be the Z-scheme heterojunction with an improved transfer efficiency of photogenerated electron–hole pairs and strong redox capacity, which can be confirmed by radical trapping experiments, DMPO-ESR technique and valence band XPS spectra measurements.

This is a preview of subscription content, log in to check access.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11


  1. 1

    Valero A, Valero A, Calvo G et al (2018) Global material requirements for the energy transition. An exergy flow analysis of decarbonisation pathways. Energy 159:1175–1184

  2. 2

    Wang CY, Zhang X, Zhang YJ et al (2018) Direct generation of hydroxyl radicals over bismuth oxybromide nanobelts with tuned band structure for photocatalytic pollutant degradation under visible light irradiation. Appl Catal B Environ 237:464–472

  3. 3

    Di Paola A, Garcia-Lopez E, Marci G et al (2012) A survey of photocatalytic materials for environmental remediation. J Hazard Mater 212:3–29

  4. 4

    Tan HL, Amal R, Ng YH (2017) Alternative strategies in improving the photocatalytic and photoelectrochemical activities of visible light-driven BiVO4: a review. J Mater Chem 5:16498–16521

  5. 5

    Yuan XZ, Jiang LB, Chen XH et al (2017) Highly efficient visible-light-induced photoactivity of Z-scheme Ag2CO3/Ag/WO3 photocatalysts for organic pollutant degradation. Environ Sci Nano 4:2175–2185

  6. 6

    Ye Y, Feng Y, Bruning H et al (2018) Photocatalytic degradation of metoprolol by TiO2 nanotube arrays and UV-LED: effects of catalyst properties, operational parameters, commonly present water constituents, and photo-induced reactive species. Appl Catal B Environ 220:171–181

  7. 7

    Al-Sabahi J, Bora T, Claereboudt M et al (2018) Visible light photocatalytic degradation of HPAM polymer in oil produced water using supported zinc oxide nanorods. Chem Eng J 351:56–64

  8. 8

    Deng F, Zhang Q, Yang LX et al (2018) Visible-light-responsive graphene-functionalized Bi-bridge Z-scheme black BiOCl/Bi2O3 heterojunction with oxygen vacancy and multiple charge transfer channels for efficient photocatalytic degradation of 2-nitrophenol and industrial wastewater treatment. Appl Catal B Environ 238:61–69

  9. 9

    Xu BT, Ahmed MB, Zhou JL et al (2017) Photocatalytic removal of perfluoroalkyl substances from water and wastewater: mechanism, kinetics and controlling factors. Chemosphere 189:717–729

  10. 10

    Kovalevskiy NS, Lyulyukin MN, Selishchev DS et al (2018) Analysis of air photocatalytic purification using a total hazard index: effect of the composite TiO2/zeolite photocatalyst. J Hazard Mater 358:302–309

  11. 11

    Luo JM, Dong GH, Zhu YQ et al (2017) Switching of semiconducting behavior from n-type to p-type induced high photocatalytic NO removal activity in g-C3N4. Appl Catal B Environ 214:46–56

  12. 12

    Guo JY, Liang J, Yuan XZ et al (2018) Efficient visible-light driven photocatalyst, silver (meta) vanadate: synthesis, morphology and modification. Chem Eng J 352:782–802

  13. 13

    Wu ZZ, Yuan XZ, Wang H et al (2017) Facile synthesis of a novel full-spectrum-responsive Co2.67S4 nanoparticles for UV-, vis- and NIR-driven photocatalysis. Appl Catal B Environ 202:104–111

  14. 14

    Vargas MA, Rodriguez-Paez JE (2017) Amorphous TiO2 nanoparticles: synthesis and antibacterial capacity. J Non-Crystalline Solids 459:192–205

  15. 15

    Yi ZG, Ye JH, Kikugawa N et al (2010) An orthophosphate semiconductor with photooxidation properties under visible-light irradiation. Nat Mater 9:559–564

  16. 16

    Jiang ZY, Liang XZ, Liu YY et al (2017) Enhancing visible light photocatalytic degradation performance and bactericidal activity of BiOl via ultrathin-layer structure. Appl Catal B Environ 211:252–257

  17. 17

    Wu M, Zhang J, He BB et al (2019) In-situ construction of coral-like porous P-doped g-C3N4 tubes with hybrid 1D/2D architecture and high efficient photocatalytic hydrogen evolution. Appl Catal B Environ 241:159–166

  18. 18

    Zhou P, Lai JP, Tang YH et al (2018) Amorphous FeCoPOx nanowires coupled to g-C3N4 nanosheets with enhanced interfacial electronic transfer for boosting photocatalytic hydrogen production. Appl Catal B Environ 238:161–167

  19. 19

    Zhang LX, Xie CM, Jiu HF et al (2018) Synthesized hollow TiO2@g-C3N4 composites for carbon dioxide reduction under visible light. Catal Lett 148:2812–2821

  20. 20

    Murugesan P, Narayanan S, Manickam M et al (2018) A direct Z-scheme plasmonic AgCl@g-C3N4 heterojunction photocatalyst with superior visible light CO2 reduction in aqueous medium. Appl Surf Sci 450:516–526

  21. 21

    Xiao G, Xu SN, Li PF et al (2018) Visible-light-driven activity and synergistic mechanism of TiO2@g-C3N4 heterostructured photocatalysts fabricated through a facile and green procedure for various toxic pollutants removal. Nanotechnology 29:315601

  22. 22

    Qian XF, Wu YW, Kan M et al (2018) FeOOH quantum dots coupled g-C3N4 for visible light driving photo-Fenton degradation of organic pollutants. Appl Catal B Environ 237:513–520

  23. 23

    Zhang RY, Ma MZ, Zhang Q (2018) Multifunctional g-C3N4/graphene oxide wrapped sponge monoliths as highly efficient adsorbent and photocatalyst. Appl Catal B Environ 235:17–25

  24. 24

    Li CM, Yu SY, Dong HJ et al (2018) Z-scheme mesoporous photocatalyst constructed by modification of Sn3O4 nanoclusters on g-C3N4 nanosheets with improved photocatalytic performance and mechanism insight. Appl Catal B Environ 238:284–293

  25. 25

    Li YD, Ruan ZH, He YZ et al (2018) In situfabrication of hierarchically porous g-C3N4 and understanding on its enhanced photocatalyticactivity based on energy absorption. Appl Catal B Environ 236:64–75

  26. 26

    Zhou M, Yang PJ, Yuan RS (2017) Modulating crystallinity of graphitic carbon nitride for photocatalytic oxidation of alcohols. Chemsuschem 23:4451–4456

  27. 27

    Wang YY, Zhao S, Zhang YW et al (2018) Facile synthesis of self-assembled g-C3N4 with abundant nitrogen defects for photocatalytic hydrogen evolution. ACS Sustain Chem Eng 6:10200–10210

  28. 28

    Wang J, Wang GH, Wei XH et al (2018) ZnO nanoparticles implanted in TiO2 macrochannels as an effective direct Z-scheme heterojunction photocatalyst for degradation of RhB. Appl Surf Sci 456:666–675

  29. 29

    Zhou CY, Xu P, Lai C et al (2019) Rational design of graphic carbon nitride copolymers by molecular doping for visible-light-driven degradation of aqueous sulfamethazine and hydrogen evolution. Chem Eng J 359:186–196

  30. 30

    Yang Y, Zhang C, Lai C et al (2018) BiOX (X=Cl, Br, I) photocatalytic nanomaterials: applications for fuels and environmental management. Adv Colloid Interface Sci 254:76–93

  31. 31

    Yang Y, Zeng ZT, Zeng GM et al (2019) Ti3C2 Mxene/porous g-C3N4 interfacial Schottky junction for boosting spatial charge separation in photocatalytic H2O2 production. Appl Catal B Environ 258:117956

  32. 32

    Yi H, Yan M, Huang DL et al (2019) Synergistic effect of artificial enzyme and 2D nano-structured Bi2WO6 for eco-friendly and efficient biomimetic photocatalysis. Appl Catal B Environ 250:52–62

  33. 33

    Wang J, Wang GH, Wei XH et al (2018) ZnO nanoparticles implanted in TiO2 macrochannels as an effective direct Z-scheme heterojunction photocatalyst for degradation of RhB. Appl Surf Sci. 456:666–675

  34. 34

    Wang MG, Zhang H, Zu HL (2018) Construction of TiO2/CdS heterojunction photocatslysts with enhanced visible light activity. Appl Surf Sci 455:729–735

  35. 35

    Wu XS, Hu YD, Wang Y et al (2018) In-situ synthesis of Z-scheme Ag2CO3/Ag/AgNCO heterojunction photocatalyst with enhanced stability and photocatalytic activity. Appl Surf Sci 464:108–114

  36. 36

    Luo J, Zhou XS, Ma L et al (2016) Rational construction of Z-scheme Ag2CrO4/g-C3N4 composites with enhanced visible-light photocatalytic activity. Appl Surf Sci 390:357–367

  37. 37

    Yang Y, Zhang C, Huang DL et al (2019) Boron nitride quantum dots decorated ultrathin porous g-C3N4: intensified exciton dissociation and charge transfer for promoting visible-light-driven molecular oxygen activation. Appl Catal B Environ 245:87–99

  38. 38

    Wang YJ, Shi R, Lin J et al (2011) Enhancement of photocurrent and photocatalytic activity of ZnO hybridized with graphite-like C3N4. Energy Environ Sci 4:2922–2929

  39. 39

    Hosono E, Fujihara S, Kimura T et al (2014) Growth of layered basic zinc acetate in methanolic solutions and its pyrolytic transformationinto porous zinc oxide films. J Colloid Interface Sci 272:391–398

  40. 40

    Dong GH, Zhang LZ (2012) Porous structure dependent photoreactivity of graphitic carbon nitride under visible light. J Mater Chem 22:1160–1166

  41. 41

    Michael B, Arno P (2006) HgI2∙As4S4: an adduct from HgI2 molecules and undistorted As4S4 cages. Angewandte Chemie-International Edition 45:4464–4467

  42. 42

    Dong F, Ni ZL, Li PD et al (2015) A general method for type I and type II g-C3N4/g-C3N4 metal-free isotype heterostructures with enhanced visible light photocatalysis. New J Chem 39:4737–4744

  43. 43

    Cui YJ, Zhang JS, Zhang GG et al (2011) Synthesis of bulk and nanoporous carbon nitride polymers fromammonium thiocyanate for photocatalytic hydrogen evolution. J Mater Chem 21:13032–13039

  44. 44

    Chen XY, Pan QJ, Guo YR (2018) One-pot synthesis of the g-C3N4/S-doped ZnO composite with assistance of sodium lignosulfonate and its enhanced photodegradation on organic pollutants. Mater Res Bull 107:164–170

  45. 45

    Peng Y, Chen QG, Wang D (2015) Synthesis of one-dimensional WO3-Bi2WO6 heterojunctions with enhanced photocatalytic activity. CrystEngComm 17:569–576

  46. 46

    Kuang PY, Su YZ, Chen GF (2015) g-C3N4 decorated ZnO nanorod arrays for enhanced photoelectrocatalytic performance. Appl Surf Sci 358:296–303

  47. 47

    Yue B, Li QY, Iwai H (2011) Hydrogen production using zinc-doped carbon nitride catalyst irradiated with visible light. Sci Technol Adv Mater 12:034401

  48. 48

    Jiang GM, Li XW, Lan MN et al (2017) Monodisperse bismuth nanoparticles decorated graphitic carbon nitride: enhanced visible-light-response photocatalytic NO removal and reaction pathway. Appl Catal B Environ 205:532–540

Download references


This work was supported by the National Natural Science Foundation of China (21276132) and Key R & D project of Shandong Province (2016GSF117029).

Author information

Correspondence to Weiwen Wang.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Guo, X., Duan, J., Li, C. et al. Highly efficient Z-scheme g-C3N4/ZnO photocatalysts constructed by co-melting-recrystallizing mixed precursors for wastewater treatment. J Mater Sci 55, 2018–2031 (2020).

Download citation