Zn-O-Sn Covalency Interface Governs the Intrinsic Activity of the Zn2sno4/Sno2 Heterostructure for Boosting Hydrogen Peroxide Production

Abstract

Electrocatalyzing oxygen to hydrogen peroxide (H2O2) is desirable for long-term, renewable, sustainable and clean fuel production on Earth. In this study, an atomic-shared heterointerface was constructed between Zn2SnO4 and SnO2 via a self-templating co-precipitation method. Theoretical and experimental analysis confirms the delocalization effects of electrons within the Zn2SnO4/SnO2 spinel structure. The resulting Zn-O-Sn bridge (asymmetric sites) modulates electronic transport at the interface, and the intensified Zn-O bond facilitates proton adsorption and transfer kinetics. Moreover, strong interface coupling between Zn2SnO4 and SnO2 enhances electron transfer, which effectively promoting the *OOH intermediate favorable for H2O2 production and reducing H2O generation simultaneously. Consequently, the Zn2SnO4/SnO2 heterostructure delivers a boosted H2O2 selectivity of nearly 100.0% and a high production rate of 7.1 mol gcat−1 h−1 at 120 mA cm−2 with a Faraday efficiency (FE) of approximately 80%. Additionally, the Zn2SnO4/SnO2 demonstrates excellent stability during long-term operation.

Keywords: spinel structure, heterostructure, asymmetric sites, 2e-ORR, Hydrogen peroxide