Cyano-rich porous carbon nitride nanosheets for enhanced photocatalytic H2O2 production

• Published in: Journal of environmental chemical engineering Vol. 11; no. 3; p. 110138
• Main Authors: Zhou, Chengqian, Song, Yanhua, Wang, Zhuanghao, Liu, Jinyuan, Sun, Peipei, Mo, Zhao, Yi, Jianjian, Zhai, Linzhi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023
• Subjects: Carbon nitride; Gas template method; Photocatalytic H2O2 production; Porous thin-layer structure; Photocatalytic H2O2 production; Gas template method; Porous thin-layer structure; Carbon nitride
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2023.110138

The gas template method is used to introduce the cyano (-CN) group and porous thin-layer structure into g-C3N4 simultaneously. The resulting material exhibits a synergistic effect between the -CN group and porous thin-layer structure, which broadens the optical absorption range of g-C3N4 and enhances electron transfer and transformation. The rotating ring-disk electrode (RRDE) experiments demonstrate that cyano-rich porous ultrathin carbon nitride significantly improves the selectivity of 2e- oxygen reduction reaction (ORR), with the selectivity of 93% compared to the 66% of the original carbon nitride at a potential of 0.3 V versus RHE. Additionally, the H2O2 yield for the modified carbon nitride is twice than that of the original carbon nitride material (99.11 μM vs 49.79 μM). The mechanism for photocatalytic H2O2 production involves a two-step one-electron reaction. The modified catalyst is recyclable and can be used for an extended period of time. Overall, this study provides a viable method for modifying g-C3N4 to improve its photocatalytic activity and selectivity towards the 2e- ORR. •A cyano-rich porous carbon nitride was prepared using a gas-templated sacrificial agent-induced bottom-up approach.•The presence of -C≡N group improves its ability to reduce electrons and increases its efficiency in utilizing light.•UCN4 exhibits exceptional photocatalytic activity for the production of H2O2 and has high selectivity for the 2e- ORR.