Modulation of charge carrier pathways in CdS nanospheres by integrating MoS2 and Ni2P for improved migration and separation toward enhanced photocatalytic hydrogen evolution

Abstract

The photocatalytic hydrogen evolution reaction using semiconductor nanostructures has received considerable attention in tackling energy and pollution problems. Although several semiconductor photocatalysts have been developed, materials satisfactory in all aspects (e. g., economical and eco-friendly with high efficiency) are still to be developed. Herein, a new and efficient noble-metal-free CdS/MoS2@Ni2P ternary nanohybrid photocatalyst is prepared using a combined hydrothermal and metal-organic framework template strategy. The designed nanostructures show an appealing hydrogen evolution rate, which is 69.29-fold higher than the bare CdS nanostructures and almost 6-fold higher than the CdS-Pt nanocomposites, with an apparent quantum efficiency of 24.4%. Furthermore, the rate enhancement factor of photocatalytic hydrogen evolution in the presence of MoS2 and Ni2P on CdS is much larger than that of several cocatalyst-modified CdS nanostructures reported earlier. The enhanced photocatalytic hydrogen evolution rate is attributed to better migration and separation efficiency in CdS/MoS2@ Ni2P than bare CdS, which is supported by photoluminescence, dynamics, photocurrent, and impedance studies. We anticipate that the work presented here may open up new insights for the utilization of low-cost CdS/MoS2@ Ni2P hybrid nanostructures as a substitute for noble metals for effective photocatalytic hydrogen evolution.