Construction of 2D/2D g-C3N4/CeO2 heterostructure and its oxygen vacancy mediated photocatalytic activity

CeO2 sheets (CeO2-S) through hydrogen treatment (CeO2-S-H2) have been coupled with carboxylated g-C3N4 (C-g-C3N4) to construct 2D/2D C-g-C3N4/CeO2-S-H2 heterostructure. The ratio of Ce3+/Ce4+ in CeO2-S was increased from 28.2 % to 32.08 % in CeO2-S-H2. Experimental results demonstrated the CO yields in 8 h on 60 % C-g-C3N4/CeO2-S-H2 were 2.41, 6.83 and 1.72 times of that of pure C-g-C3N4, CeO2-S and CeO2-S-H2. Meanwhile, it also exhibited the highest CH4 yields of 11.997 mu mol/g. Interestingly, CH4 yields of CeO2-S-H2 were much higher than that of CeO2-S, verifying oxygen vacancy introduction can effectively enhance CH4 production. In addition, 60 %C-g-C3N4/CeO2-S-H2 heterostructure demonstrated the best ciprofloxacin degradation perfor-mance. It is suggested that the synergistic effects of oxygen vacancy introduction and heterojunction construction promoted charges transfer and separation.

Automated summary

CeO2 sheets (CeO2-S) were hydrogen treated (CeO2-S-H2) and coupled with carboxylated g-C3N4 (C-g-C3N4) to form a 2D/2D C-g-C3N4/CeO2-S-H2 heterostructure. The introduction of oxygen vacancies in CeO2-S-H2 increased the ratio of Ce3+/Ce4+. The experimental results showed that the CO yields on 60% C-g-C3N4/CeO2-S-H2 were 2.41, 6.83, and 1.72 times higher than that of pure C-g-C3N4, CeO2-S, and CeO2-S-H2, respectively. Furthermore, the highest CH4 yields of 11.997 mu mol/g were obtained on CeO2-S-H2, indicating the effective enhancement of CH4 production by introducing oxygen vacancies. The 60% C-g-C3N4/CeO2-S-H2 heterostructure also demonstrated the best performance in ciprofloxacin degradation, suggesting that the synergistic effects of oxygen vacancy introduction and heterojunction construction promoted charge transfer and separation.