In situ photodeposition of amorphous NixP on CdS nanorods for efficient visible-light photocatalytic H2 generation

Abstract

Exploring robust and low-cost co-catalysts to substitute precious noble metals is of great importance in both fundamental research and practical applications. In this research, after loading amorphous Ni_xP on CdS nanorods by a photodeposition method, the photocatalytic hydrogen production activity of the as-prepared Ni_xP/CdS from water splitting was significantly improved. The optimal hydrogen production rate of the Ni_xP/CdS photocatalyst with a 20 min photodeposition time can reach up to 69.2 mmol h⁻¹ g⁻¹, which is 27 times higher than that of bare CdS and 6 times higher than that of 1 wt% Pt/CdS, respectively. The presence of Ni_xP can efficiently promote the separation of photo-generated electron–hole pairs of CdS, which was supported by the enhanced photocurrent, reduced photoelectric impedance, weakened fluorescence intensity, extended fluorescence lifetime and lower overpotential of the hydrogen evolution reaction. A possible mechanism of photocatalytic H₂ evolution over Ni_xP/CdS was proposed, which revealed that amorphous Ni_xP provided active sites and excellent electron transfer mediators for the photocatalytic reaction. This study sheds new light on how to design low-cost, high-efficiency composite materials towards photocatalytic hydrogen evolution.