Improved Surface Reaction Kinetics in Red Phosphorus by Oxidation State for Efficient CO2 Photoreduction

Abstract

Engineering surface reaction kinetics plays a vital role in promoting CO₂ photoreduction reaction (CO₂ PRR) efficiency but remains formidably challenging. Here, we demonstrate that the regulation of the surface oxidation state is an effective strategy for the unification of the adsorption sites and reactive centers, which significantly improves the reaction kinetics and CO₂ PRR efficiency. Taking advantage of the concept, we further propose p–p orbital hybridization between P atoms and the adjacent O atoms in BiVO₄ at the interface constructed in the O-RP/BiVO₄ Z-scheme heterostructure to create the oxidation state of RP. Theoretical calculations and spectral characterizations reveal that the interfacial atomic orbital hybridization lowers the CO₂ activation energy barrier through the stabilization of the COOH* intermediate and facilitates the charge separation and transfer. Consequently, the optimized photocatalyst exhibits an excellent performance for sacrificial reagent-free CO₂ PRR, with a production rate of 208 and 26.2 μmol g^–1 h^–1 for CO and CH₄, respectively, ca. 21-fold higher than that of pristine RP and topping most of the hybrid photocatalysts with a noble metal as cocatalysts. This work provides critical insight for the design of high-efficiency photocatalysts for CO₂ PRR.