Multi-modal optimization of bismuth vanadate photoanodes via combinatorial alloying and hydrogen processing

Alloying transition metals, such as Mo, into BiVO_4 has emerged as the primary mechanism for improving carrier transport in this photoanode for solar fuels production. The present work establishes the generality of improving photoelectrochemical performance through co-alloying with a transition metal electron donor and a structure-modulating rare earth. Further improvement for all such alloys is obtained by annealing the oxide materials in H_2, ultimately producing photoanodes with above 3 mA cm^(−2) photocurrent density under AM 1.5G illumination, in the top tier of compact BiVO_4 films