Enhanced Photoelectrochemical and Photocatalytic Properties of CdS Nanowires Decorated with Ni 3 S 2 Nanoparticles under Visible Light Irradiation

Abstract

© 2019 by the Authors. Ni3S2/CdS nanocomposites based on zero-dimensional Ni3S2 nanoparticles (NPs) and one-dimensional CdS nanowires (NWs) were synthesized via a two-step solvothermal approach. These nanocomposites were characterized using a combination of experimental techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy, and photoelectrochemistry method. The Ni3S2/CdS nanocomposites exhibit much higher photocatalytic hydrogen evolution activity than individual CdS NWs or Ni3S2 NPs under visible light irradiation (? = 400 nm) from water. Photoelectrochemical (PEC) and photocatalytic properties of the Ni3S2/CdS nanocomposites were investigated as a function of the molar ratio between Ni3S2 and CdS. In addition, ultrafast transient absorption (TA) spectroscopy was employed to probe the charge carrier dynamics, which is about four times shorter in 10%-Ni3S2/CdS than pure CdS NWs. These results suggest efficient charge transfer between CdS and Ni3S2 at the interface, which is desired for PEC and photocatalytic applications.