Photocatalytic production of H2O2 from water and dioxygen only under visible light using organic polymers: Systematic study of the effects of heteroatoms

Abstract

The photocatalytic production of H2O2 that needs dioxygen, water, and light only has been proposed and investigated. However, most of the studies employed organic electron donors. In this work, organic photocatalysts that can produce H2O2 without organic electron donors are designed with a bottom-up approach. Although the heptazine-based g-C3N4 cannot induce water oxidation, a different kind of organic polymer (CN) obtained from the condensation of s-triazine and pyrimidine can produce H2O2 via dioxygen reduction coupled with water oxidation. The incorporation of O and P elements in CN structure (CNO, CNP, CNOP) increases the visible light absorption and hinders the photodecomposition of H2O2, respectively. The C-O and P-O bonds act as the charge trapping sites and also the preferred adsorption sites of a key intermediate, •OOH. As a result, the CNOP exhibits the highest production of H2O2 using dioxygen, water, and visible light only.