Noble metal-free bimetallic NiCo decorated Zn0.5Cd0.5S solid solution for enhanced photocatalytic H2 evolution under visible light

As we know, noble metal (Pt, Pd and Au) with appropriate adsorption free energy of H atoms and higher work function as cocatalyst has been considered to be an effective tactic to enhance photocatalytic activity. However, they are limited severely by scarcity and high-cost. Herein, Zn0.5Cd0.5S solid-solution photocatalyst decorated with noble metal-free NiCo cocatalyst has been successfully obtained through one-step photochemical route. It is found that the lifespan of charge carriers of Zn0.5Cd0.5S@NiCo can be prolonged dramati-cally after modification, and the photocatalytic H-2 rate reach to 34.7 mmol g(-1)h(-1) is nearly 9 times higher than the bare Zn0.5Cd0.5S (lambda >= 420 nm). The superior photocatalytic activity for ZCS@NiCo could be mainly ascribed to higher separation and transfer efficiency of photogenerated carriers by introduced bimetallic NiCo cocatalysts possessing the superior electron transfer property and reducing the onset over-potential of water reduction, which was proved by experiment. This study can provide a potential strategy to design a more efficient noble metal-free cocatalyst over photocatalyst. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.