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

Photocatalytic hydrogen peroxide (H2O2) production is a promising strategy to replace the tradi-tional 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 photocata-lytic H2O2 production. X-ray photoelectron spectroscopy and Fourier-transform infrared spectros-copy indicated that oxygen-containing functional groups (-COOH and C-O-C) were obtained. Elec-tron paramagnetic resonance confirmed the successful introduction of nitrogen vacancies. OCN exhibited efficient photocatalytic H2O2 production performance of 1965 mu mol 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 produc-tion rate (5781 mu mol 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. center dot O2- obtained by O2 reduction react-ed with adjacent holes to generate 1O2, which could efficiently generate H2O2 with isopropanol. Ad-ditionally, PO43-, as a stabilizer, inhibited the decomposition of H2O2.(c) 2022, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, oxygen-rich g-C3N4 with abundant nitrogen vacancies (OCN) was synthesized for efficient photocatalytic H2O2 production. The results showed that OCN exhibited enhanced adsorption of oxygen, enlarged specific surface area, and promoted carrier separation.