The construction of a c-SnO2/a-ZnSnO3 heterostructure with abundant interfaces through topological transformation for efficient electrocatalytic CO2 reduction

Abstract

The construction of catalysts with abundant active sites and efficient electron transfer properties is of great significance for the CO₂ reduction reaction (CO₂RR). In this work, a crystalline tin oxide (SnO₂)/amorphous zinc metastannate (ZnSnO₃) (c-SnO₂/a-ZnSnO₃) heterostructure has been developed through topotactic transformation under post-annealing. The c-SnO₂/a-ZnSnO₃ heterostructure can achieve a dual function by modulating the electronic structure and the local reaction microenvironment of the catalyst, which simultaneously enhances the CO₂RR and suppresses the competing HER. Through a series of structural analysis, electrochemical tests and in situ characterization, the enhanced electrocatalytic performance of the c-SnO₂/a-ZnSnO₃ heterostructure can be ascribed to the following factors: (1) the unique c-SnO₂/a-ZnSnO₃ heterostructures provide large numbers of unsaturated active sites, facilitating the adsorption and reduction of CO₂ and intermediates. (2) The abundant and robust crystalline/amorphous interfaces, as well as the optimized electronic structure, improve the PCET process, thus promoting the CO₂RR performance.