Smooth charge transfer at the Ag2MoO4/Mn-Fe PBAs S-scheme interface for photo-driven CO2 reduction

Abstract

Photocatalysis exhibits great potential for applications in solving energy and environmental problems, and has received widespread attention. This article constructs a new type of Mn-Fe Prussian blue analogues S-scheme mechanism photocatalytic material. The material is composed of oxidized photocatalysts (Ag₂MoO₄) and reduced photocatalysts (Mn-Fe PBAs). The composite photocatalyst constructed in this way shows advantages such as a wide spectral response range, high charge carrier separation efficiency, and strong oxidation–reduction ability, which can significantly enhance photocatalytic efficiency. By studying the construction method and CO₂ reduction performance of the photocatalyst, the structure-performance relationship can be clarified. The CO production rate is 43.3 μmol/g/h, and the selectivity can reach 94.9 %, which is far superior to the current mainstream photocatalytic system. The electron transfer kinetics and S-scheme charge separation mechanism between the Mn-Fe PBAs and Ag₂MoO₄ interfaces are explained by steady-state surface photovoltage spectroscopy (SS-SPS) and near ambient pressure XPS (NAP-XPS). In-situ DRIFTS techniques are used to monitor the changes of transition intermediates, and combined with theoretical calculations, the activation mechanism of CO₂ by the Mn-Fe catalytic site is deeply revealed at the atomic level. This study provides new theoretical guidance and profound insights for the construction of Prussian blue analogues photocatalysts.