Highly efficient photocatalytic H2O2 production by tubular g-C3N4/ZnIn2S4 nanosheet heterojunctions via improved charge separation

Hydrogen peroxide is an environment-friendly reactive oxygen species and a significant green oxidant. However, the highly efficient and sustainable production of H2O2 remains a challenge. Herein, we demonstrated a state-of-the-art photocatalytic method for H2O2 production using an optimal tubular graphic carbon nitride (TCN)/ZnIn2S4 (ZIS) heterojunction. Within 3 h, a H2O2 production rate of 2.77 mmol g−1 h−1 was achieved by the TCN/ZIS heterojunction, which is 3.4- and 23.1-fold higher than that obtained by its individual TCN and ZIS components, respectively. Experimental results showed that the excellent photoactivity of TCN/ZIS is mainly due to the formation of heterojunction, which improves the charge separation ability and thereby promotes the proton-coupled electron transfer by initially reducing O2 to ·O2− and subsequently generating H2O2. This work has developed an efficient and green strategy for H2O2 production with scientific and practical value for environmental remediation.