Efficient photocatalytic production of hydrogen peroxide by Z-scheme resorcinol-formaldehyde resin/g-C3N4 heterostructure under visible light

Abstract

Photocatalytic production of hydrogen peroxide (H2O2) in pure water system under visible light is very desirable. Resorcinol-Formaldehyde (RF) resin has proven to be a promising photocatalyst for this purpose because of its high solar-to-chemical conversion (SCC) (∼0.5 %). However, RF resin prepared at low hydrothermal temperature is not satisfactory because the CO group, which is detrimental to the H2O2 production will only be generated when it is >250 °C. Herein, we successfully prepared a Z-scheme heterostructure between RF resin and g-C3N4 by mechanochemical method. The ball milled RF-g-C3N4 (RF-CN-bm) not only achieved CO group at a lower temperature (180 °C) but also produced as high as 72.86 umol H2O2 in 12 h under visible light, which is 2.37 times higher than that of bare RF resin. Moreover, we found that Z-scheme heterojunction was formed between RF and g-C3N4, which allowed the H2O2 production both through O2 reduction by CB e− of g-C3N4 and the combination of ∙HO that produced by oxidation of OH– by VB h+ of RF. In principle, the mechanochemical assembled RF-CN-bm developed in this study paves a new way for low-cost and high-performance H2O2 production under visible light.