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

In this study, WO 3 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 WO 3 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 WO 3 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 WO 3 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 WO 3 -based 2D materials.