Chinese Journal of Catalysis ›› 2022, Vol. 43 ›› Issue (10): 2690-2698.DOI: 10.1016/S1872-2067(22)64114-7

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An efficient strategy for photocatalytic hydrogen peroxide production over oxygen-enriched graphitic carbon nitride with sodium phosphate

Yu Zhanga,b, Ling Zhanga, Di Zenga,b, Wenjing Wanga, Juxue Wanga,b, Weimin Wanga, Wenzhong Wanga,b,c,*()   

  1. aState Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
    bCenter of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
    cSchool of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, Zhejiang, China
  • Received:2022-03-14 Accepted:2022-04-13 Online:2022-10-18 Published:2022-09-30
  • Contact: Wenzhong Wang
  • Supported by:
    National Natural Science Foundation of China(51972325);National Natural Science Foundation of China(51972327);National Natural Science Foundation of China(52172256)

Abstract:

Photocatalytic hydrogen peroxide (H2O2) production is a promising strategy to replace the traditional production processes; however, the inefficient H2O2 productivity limits its application. In this study, oxygen-rich g-C3N4 with abundant nitrogen vacancies (OCN) was synthesized for photocatalytic H2O2 production. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy indicated that oxygen-containing functional groups (-COOH and C-O-C) were obtained. Electron paramagnetic resonance confirmed the successful introduction of nitrogen vacancies. OCN exhibited efficient photocatalytic H2O2 production performance of 1965 µmol L-1 h-1 in air under visible-light irradiation. The high H2O2 production was attributed to the enhanced adsorption of oxygen, enlarged specific surface area, and promoted carrier separation. An increased H2O2 production rate (5781 µmol L-1 h-1) was achieved in a Na3PO4 solution. The improved performance was attributed to the changed reactive oxygen species. Specifically, the adsorbed PO43- on the surface of the OCN promoted the transfer of holes to the catalyst surface. •O2- obtained by O2 reduction reacted with adjacent holes to generate 1O2, which could efficiently generate H2O2 with isopropanol. Additionally, PO43-, as a stabilizer, inhibited the decomposition of H2O2.

Key words: Photocatalysis, Hydrogen peroxide production, Graphitic carbon nitride, Singlet oxygen, Sodium phosphate