Revealing the effects of transition metal doping on CoSe cocatalyst for enhancing photocatalytic H2 production

Having an insight into the optimizations of intrinsic properties of cocatalysts via doping foreign atoms to promote solar-driven water splitting into hydrogen (H2) energy conversion is increasingly important, but it remains a challenging scheme. Herein, zero-dimensional/one-dimensional (0D/1D) structured TMCoSe/CdS0.95Se0.05 was successfully synthesized through a two-pot hydrothermal treatment. Experimental results show that the FeCoSe/CdS0.95Se0.05 photocatalyst exhibits the most excellent photocatalytic H2 evolution performance (513.76 μmol h−1), which is 36.6 times and 2.0 times higher than that of CdS0.95Se0.05 and the optimal CoSe/CdS0.95Se0.05, respectively. In addition, photochemical and photoluminescence results reveal that the FeCoSe/CdS0.95Se0.05 sample shows the most rapid carrier dynamics among all samples. Theoretical calculations demonstrate that the excellent activity of FeCoSe/CdS0.95Se0.05 nanocomposite can be attributed to the formation of Schottky-type heterojunction between semi-metallic FeCoSe cocatalyst and CdS0.95Se0.05, which can enhance the efficiency of charge carrier separation and utilization, thus promoting the H2-generation performance.