Construction of an Electron Capture and Transfer Center for Highly Efficient and Selective Solar-Light-Driven CO Conversion.

Exploring high-efficiency photocatalysts for selective CO reduction is still challenging because of the limited charge separation and surface reactions. In this study, a noble-metal-free metallic VSe nanosheet was incorporated on g-CN to serve as an electron capture and transfer center, activating surface active sites for highly efficient and selective CO photoreduction. X-ray photoelectron spectroscopy (XPS), soft X-ray absorption spectroscopy (sXAS), and femtosecond transient absorption spectroscopy (fs-TAS) unveiled that VSe could capture electrons, which are further transferred to the surface for activating active sites. diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations revealed a kinetically feasible process for the formation of a key intermediate and confirmed the favorable production of CO on the VSe/PCN (protonated CN) photocatalyst. As an outcome, the optimized VSe/PCN composite achieved 97% selectivity for solar-light-driven CO conversion to CO with a high rate of 16.3 μmol·g·h, without any sacrificial reagent or photosensitizer. This work offers new insights into the photocatalyst design toward highly efficient and selective CO conversion.