Three-Dimensional FTO/TiO2/BiVO4 Composite Inverse Opals Photoanode with Excellent Photoelectrochemical Performance

A poor electron transport property, short charge carrier diffusion lengths, and slow water oxidation kinetics severely limit the photoelectrochemical (PEC) performance of the BiVO4 photoelectrodes. To address these problems, we report the design and fabrication of a three-dimensional FTO/TiO2/BiVO4 core–shell inverse opals photoanode for PEC hydrogen production by combining atomic layer deposition and electrodeposition routes for TiO2 and BiVO4 layer deposition on F:SnO2 (FTO) inverse opal skeletons, respectively. Benefiting from the highly conductive transparent FTO invese opal networks providing fast electron pathways and TiO2/BiVO4 heterojunctions, the as-fabricated 3D FTO/TiO2/BiVO4 inverse opals photoanode delivers excellent PEC performance with a maximum photocurrent density of 4.11 mA/cm2 at 1.23 V vs a reversible hydrogen electrode in the presence of a hole scavenger in contrast to that of the counterparts FTO/TiO2 and FTO/BiVO4 inverse opals electrodes, respectively, which could be attributed to the significantly improved charge transport and separation efficiency.