Pt₃Co Alloy Nanoclusters as Charge Separation and Reduction Sites for the Enhanced Photoreduction of CO₂ on Mo₂C MXene

The design and preparation of highly efficient and stable cocatalysts are critical for improving the photocatalytic CO2 reduction performance. A traditional cocatalyst consists of metal nanoparticles that facilitate the separation of photoinduced electron–hole pairs and the reduction of protons. In this research, the Pt3Co alloy nanocluster cocatalyst was loaded onto Mo2C MXene to enhance photocatalytic CO2 reduction activity and CO selectivity. As anticipated, the optimized Pt3Co/Mo2C-5 exhibited a 3.2-fold increase in CO2-to-CO conversion efficiency compared to individual Mo2C MXene, with selectivity rising from 63.94% to 81.75%. The photoelectrochemical experiments and in situ transmission FTIR results further validated that the Pt3Co/Mo2C catalyst possesses excellent charge separation efficiency, providing more reduction active sites for CO2 reduction reactions. This work offers novel insights into the utilization of alloy clusters and Mo2C MXene in photocatalytic CO2 reduction.