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

• A Z-scheme heterostructure between RF resin and g-C 3 N 4 was prepared via ball-milling. • The C=O group was formed in RF resin after adding g-C 3 N 4 at 180 °C. • RF-CN-bm produced 2.37 times higher of H 2 O 2 than RF resin under visible light. Photocatalytic production of hydrogen peroxide (H 2 O 2 ) 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 C=O group, which is detrimental to the H 2 O 2 production will only be generated when it is greater than 250 °C. Herein, we successfully prepared a Z-scheme heterostructure between RF resin and g-C 3 N 4 by mechanochemical method. The ball milled RF-g-C 3 N 4 (RF-CN-bm) not only achieved C=O group at a lower temperature (180 °C) but also produced as high as 72.86 umol H 2 O 2 in 12 hours 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-C 3 N 4 , which allowed the H 2 O 2 production both through O 2 reduction by CB e − of g-C 3 N 4 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 H 2 O 2 production under visible light.