Mo6+ Doped BiVO4 with improved Charge Separation and Oxidation Kinetics for Photoelectrochemical Water Splitting

Monoclinic bismuth vanadate (BiVO4) has been widely applied as a promising n-type semiconductor for photoelectrochemical (PEC) water splitting because of its low cost, environmentally friendly, and relatively narrow band gap of similar to 2.4 eV. Here, we developed a facile fabrication of Mo doped BiVO4 photoanode on the fluorine-doped tin oxide substrate by electrodeposition method and used these samples to better understand the doping effect for charge separation and charge oxidation kinetics. Compared with the undoped BiVO4 photoanode, the optimized Mo doped BiVO4 (3AMo: BV) produced a much higher photocurrent of 1.91 mA/cm(2) at 1.23 V vs. RHE under AM 1.5G illumination for water oxidation. The results of the photoelectric conversion kinetics for various samples revealed that the charge separation and oxidation kinetics efficiencies for 3AMo: BV sample are 74.42% and 49.25% at 1.23 V vs. RHE, while the values for undoped BiVO4 are 48.04% and 32.98%, respectively. The improved PEC performance for Mo doped BiVO4 is mainly ascribed to the crystal deformation caused by larger tetrahedral ionic VO4 and higher photovoltage generated by the interface of photoanode and electrolyte. (C) 2017 Elsevier Ltd. All rights reserved.