Modulating electronic structure and sulfur p-band center by anchoring amorphous Ni@NiSx on crystalline CdS for expediting photocatalytic H2 evolution

Photocatalytic water splitting is a prospective approach to address the energy and environmental challenges. Herein, an amorphous Ni@NiS x cocatalyst has been fabricated and simultaneously assembled onto CdS to form amorphous-crystalline Ni@NiS x -CdS photocatalyst via a partial reduction strategy. Comprehensive experiments and theoretical calculations demonstrate that the synergistic effects between the electronic coupling of amorphous-crystalline interface and the gradient work function variation induced by Ni nanocluster encapsulation achieve the deeper downshift of the S p-band center to optimize H* intermediate adsorption, enhance charge extraction ability though Schottky junction and lower H* adsorption Gibbs free energy (ΔG H* ). Accordingly, the optimal Ni@NiS x -CdS photocatalyst delivers a remarkable photocatalytic H 2 production rate of 78.7 mmol·g −1 ·h −1 with an apparent quantum efficiency (AQE) of 36.74% at 420 nm, which is approximately 18.3 and 1.5 times than that of CdS and NiS x -CdS, respectively. This work offers a novel insight into the development of amorphous nanocomposite cocatalysts for promoting solar-to-H 2 energy conversion.