Updates on tracking charge carriers in BiVO4- and CuWO4-based photoanodes

Semiconductor ternary metal oxides (TMOs) are ideal candidates as photoanode materials for the water oxidation reaction. The dynamics of photogenerated charge carriers dictates the efficiency of photoelectrocatalytic (PEC) systems depending on both internal (inside the photoactive material) and surface (mainly due to reaction kinetics) key issues. This paper presents recent results attained with up-to-date characterization tools to decouple bulk and surface charge recombination in relation to the synthetic strategies implemented to address PEC efficiency losses in TMO photoanodes, with particular focus on BiVO4- and CuWO4-based materials. Key aspects and the perspectives in the field are finally highlighted.