NiSe/Cd_0.5Zn_0.5S Composite Nanoparticles for Use in p–n Heterojunction-Based Photocatalysts for Solar Energy Harvesting

Construction of semiconductor heterojunctions with matched energy band alignment is an efficient strategy to boost charge separation, thus raising photocatalytic activity. Developing an efficient heterojunction nanocomposite free from noble metal is of critical importance for visible-light-driven photocatalysis. Here, NiSe nanoparticles were used to construct NiSe/Cd0.5Zn0.5S p–n heterojunction-based nanocomposites by in situ chemical deposition method. The as-obtained 1%NiSe/Cd0.5Zn0.5S nanocomposite exhibits good durability and excellent photocatalytic hydrogen-generation activity of 78.01 mmol·h–1·g–1 with visible light, which is almost 3 times higher than that of Cd0.5Zn0.5S and outperforms that of 3 wt % Pt/Cd0.5Zn0.5S (63.04 mmol·h–1·g–1). The highest apparent quantum yield measured at 420 nm reached 46%. The tight contact interface and p–n junction at the interface of NiSe nanoparticles and Cd0.5Zn0.5S can efficiently promote charge separation and migration, and thus effectively improve photocatalytic activity as well as the utilization of solar energy. This work develops an efficient noble-metal-free CdxZn1–xS-based heterojunction nanocomposite to advance solar energy harvesting.