Recyclable hydrogen peroxide photosynthesis over Z-scheme In2O3/g-C3N4 heterojunction with viable reduction of superoxide radical intermediate

Abstract

Developing green and sustainable catalysts for H2O2 formation is imperative. Photocatalytic H2O2 generation offers a safe and promising alternative to traditional H2O2 synthesis method but facing challenges like low activity, and hard charge separation. Herein, maintained H2O2 photosynthesis is realized over the successful fabrication of a Z-scheme In2O3/g-C3N4 (IC) heterojunction. In this case, the material shows a laudable H2O2 generation of 475.0 μM h−1, which is superior to pure In2O3 or pristine g-C3N4. Intriguingly, the IC photocatalyst can maintain a H2O2 generation efficiency over 77 % even after 18 consecutive cycles, manifesting the stability and recyclability of the material in practical applications. Additionally, the formation of Z-scheme heterojunction expedites charge transfer and suppresses charge recombination, while the hollow structure and porous ultrathin nanosheets provide large surface area and abundant active sites for the adsorption and activation of O2, thus realizing vital superoxide radical intermediate reduction and efficient generation, and offering such a sustainable strategy for H2O2 photosynthesis.