Fabrication CdS/Au/TiO2 sandwich nanofibers for enhanced photoelectrochemical water-splitting efficiency

The sandwich-structured CdS/Au/TiO2 nanofibers (NFs) act as a photoanode in the photoelectrochemical cell (PEC) for hydrogen generation by splitting water. The gold nanoparticles sandwiched between the TiO2 nanofibers and the CdS quantum dots (QDs) layers play an important role in enhancing the solar-to-chemical-energy conversion efficiency. The structure and morphology of the materials were characterized by using field-emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The surface plasmon resonance (SPR) of the Au nanoparticles was investigated by using ultraviolet-visible (UV–Vis) diffuse reflectance spectroscopy. The PEC properties of the photoanode were measured on a three-electrode electrochemical analyzer. The obtained photoconversion efficiency of the CdS/Au/TiO2 NFs is 4.1% under simulated-sunlight illumination with a 150 W xenon lamp. Working photoelectrode stability was tested, and the mechanism of the enhanced PEC performance was discussed.