Hydroxy Acid-Assisted Synthesis of Highly Dispersed Ni-NiS on CdS as Effective Photocatalyst for Hydrogen Evolution

To achieve the well-dispersed Ni–NiS dual-cocatalysts anchored CdS, the samples have been successfully constructed by a cheap and convenient method of hydroxy acid assisted hydrothermal method. Based on the coordination and reduction effects of hydroxy acids, Ni2+ can be facilely transformed into the high dispersed dual-function sites of Ni0 electrons trap and NiS holes reservoir. The highly dispersed Ni–NiS dual-cocatalysts not only provide more dual-function active sites but also present distinctly enhanced visible light absorption, effectively separated electron hole pairs and quickly migrated charge carriers. The optimized Ni–NiS/CdS–CA presented an excellent photocatalytic H2 generation rate of 57.88 mmol·h−1·g−1, which is about 15.35 times higher than that of NiS/CdS. Moreover, the stability can be distinctly increased by modulating the surface cover of Ni–NiS with a suitable Ni/(Ni + Cd) atomic ratio. This work would provide a unique strategy to design the high effective photocatalysts with high dispersed bi-function dual cocatalysts. The well-dispersed Ni-NiS dual-cocatalysts anchored CdS in situ have been successfully constructed via the coordination and reduction effects of hydroxy acid assisted hydrothermal method. Ni-NiS/CdS-CA not only presents dual-function active sites but also exhibits distinctly enhanced visible light absorption, effectively separated electron hole pairs and quickly migrated charge carriers, resulting in a remarkable enhancement in photocatalytic H2 evolution activity.