Built-in electric field driven rapid charge transfer at the Ag3PO4/Cu-Co PBAs S-scheme interface for CO2 reduction into chemical energy

Single photocatalysts face problems such as easy recombination of photo-generated charge carriers, weak oxidation-reduction ability, and narrow spectral response range, which greatly restrict their practical applications in energy and environmental fields. This article constructs a new type of Cu-Co Prussian blue analogues S-scheme photocatalytic material. The material is composed of oxidized photocatalysts (Ag3PO4) and reduced photocatalysts (Cu-Co PBAs). By utilizing the characteristics of Cu-Co Prussian blue analogues photocatalysts, such as high conduction band position, rich catalytic sites, and small band gap, photocatalytic efficiency can be significantly enhanced. The CO production rate is 36.3 μmol/g/h, and the selectivity can reach 93.8 %, which is far superior to the current mainstream photocatalytic system. By studying the construction method and CO2 reduction performance of the composite photocatalyst, the structure-performance relationship is clarified. The steady-state photocurrent spectroscopy reveals the S-scheme mechanism photocarrier transfer and separation kinetics. Techniques such as near-ambient pressure X-ray photoelectron spectroscopy reveal the interface electron transfer mechanism. In-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Density Functional Theory calculations are used to study the formation of reaction intermediates and reveal the catalytic mechanism. This study will offer critical understanding for advancing developments of selective photocatalysts aimed at sustainable CO2 utilization.