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 BiVO 4 photoelectrodes. To address these problems, we report the design and fabrication of a three-dimensional FTO/TiO 2 /BiVO 4 core–shell inverse opals photoanode for PEC hydrogen production by combining atomic layer deposition and electrodeposition routes for TiO 2 and BiVO 4 layer deposition on F:SnO 2 (FTO) inverse opal skeletons, respectively. Benefiting from the highly conductive transparent FTO invese opal networks providing fast electron pathways and TiO 2 /BiVO 4 heterojunctions, the as-fabricated 3D FTO/TiO 2 /BiVO 4 inverse opals photoanode delivers excellent PEC performance with a maximum photocurrent density of 4.11 mA/cm 2 at 1.23 V vs a reversible hydrogen electrode in the presence of a hole scavenger in contrast to that of the counterparts FTO/TiO 2 and FTO/BiVO 4 inverse opals electrodes, respectively, which could be attributed to the significantly improved charge transport and separation efficiency.