Photoelectrochemical (PEC) water splitting, which is a type of artificial photosynthesis, is a sustainable way of converting solar energy into chemical energy. The water oxidation half-reaction has always represented the bottleneck of this process because of the thermodynamic and kinetic challenges that are involved. Several materials have been explored and studied to address the issues pertaining to solar water oxidation. Significant advances have recently been made in the use of stable and relatively cheap metal oxides, i.e., semiconducting photocatalysts. The use of BiVO₄ for this purpose can be considered advantageous because this catalyst is able to absorb a substantial portion of the solar spectrum and has favourable conduction and valence band edge positions. However, BiVO₄ is also associated with poor electron mobility and slow water oxidation kinetics and these are the problems that are currently being investigated in the ongoing research in this field. This review focuses on the most recent advances in the best-performing BiVO₄-based photoanodes to date. It summarizes the critical parameters that contribute to the performance of these photoanodes, and highlights so far unresolved critical features related to the scale-up of a BiVO₄-based PEC water-splitting device.

A new Cu-doped SrTiO₃ photocatalyst was synthesized and characterized for uses in the visible-light photocatalytic production of hydrogen from water. The photocatalytic activity was assessed based on the characterization of the photocatalysts (band gap energy, surface area, crystallinity, and morphology) and the effects of varying together the calcination temperature, the Cu:Sr mole ratio, and the photocatalyst loading amount. It was determined that the amount of hydrogen evolved was largely dictated by the amount of Cu dopant present in the photocatalysts. The created Box Behnken Design optimization scenarios suggested the conditions: 850°C, 0.01 Cu:Sr, 0.33 g loading as the optimal conditions for maximum hydrogen production holding all studied factors in range, and the conditions: 850°C, 0.01 Cu:Sr, 0.21 g loading as the optimal conditions for the maximum hydrogen production while minimizing Cu dopant and photocatalyst loading.