In situ loading of Ni2P on Cd0.5Zn0.5S with red phosphorus for enhanced visible light photocatalytic H2 evolution

Abstract

Using non-toxic red phosphorus as the phosphorus source, Ni2P was synthesized and in situ loaded on Cd0.5Zn0.5S photocatalyst by a simple solvothermal method for photocatalytic H2 evolution under visible light (λ ≥ 420 nm) irradiation. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible diffuse reflectance spectra (UV–Vis DRS), Brunauer–Emmett–Teller (BET) surface area measurements and electrochemistry techniques. The photocatalytic hydrogen evolution activity over Cd0.5Zn0.5S is significantly increased by in situ-loaded Ni2P due to the intimate interface contact and efficient charge transfer from Cd0.5Zn0.5S to Ni2P. The 4 wt%Ni2P-loaded Cd0.5Zn0.5S photocatalyst shows five times higher H2 evolution rate than that of the pristine Cd0.5Zn0.5S. The highest H2 evolution rate of 65.6 μmol/h and the apparent quantum yield (AQY) of 29% at 420 nm is achieved under the optimized conditions. The noble metal free Ni2P is stable during 20 h photocatalytic reaction.