Enhanced Photocatalytic and Photoelectrochemical Activity in the Ternary Hybrid of CdS/TiO2/WO3 through the Cascadal Electron Transfer

Abstract

The composite of different semiconductor nanoparticles may facilitate the charge separation and transfer because the difference in the band edge positions creates the potential gradient at the composite interface. For this purpose, the CdS–TiO2–WO3 ternary hybrid was successfully synthesized and characterized for the structural, optical, and morphological properties by X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, high-resolution transmission electron micrography, and energy-dispersive X-ray analysis. The photocatalytic activity was tested by monitoring the photoreduction of polyoxometalate (POM: PMo12O403–) spectrophotometrically. The photoelectrochemical (PEC) property of the ternary hybrid electrode was also characterized by the linear sweep voltammetry, and the incident photon-to-current conversion efficiency was measured as a function of wavelength. The results of both the POM reduction and photocurrent tests indicated that the photocatalytic and PEC activities of the CdS...