Enhancement of the Photoelectrochemical Performance of WO3 Vertical Arrays Film for Solar Water Splitting by Gadolinium Doping

In this study, WO3 nanoplates modified by doping with gadolinium (Gd) were synthesized by a hydrothermal method. The effect of the rare-earth element on the photoelectrochemical (PEC) performance of WO3 one- or two-dimensional (2D) materials was examined. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction were employed to examine the crystal phase and morphology of the Gd-doped nanoplates thus prepared. Results of UV-vis spectroscopy, valence-band (VB) X-ray photoelectron spectroscopy, and Mott-Schottky analyses indicated that the conduction band and VB potentials of WO3 shifted to negative values. Linear sweep voltammetry results indicated that the photocurrent density increased by 153% after modification by doping with Gd. In addition, the PEC properties of the WO3 nanoplates obtained by the intensity-modulated photocurrent spectrum and incident photon-to-current conversion efficiency measurements indicated that modification by doping with Gd has a scintillating application in improving the PEC conversion properties of WO3-based 2D materials.