Theoretical evaluation of the surface electrochemistry of perovskites with promising photon absorption properties for solar water splitting.

In this work, we present first-principles calculations describing the catalytic activity for of a set of photoelectrocatalysts identified as candidates for total water splitting in a previous screening study for bulk stability and bandgap. Our Density Functional Theory (DFT) calculations of the intermediate energetics for hydrogen evolution and oxygen evolution suggest that none of the proposed materials has the ideal combination of bandgap and surface chemical properties that should allow for total water splitting in a single material. This result suggests that co-catalysts are necessary to overcome the kinetic limitations of the both reactions, although some materials may catalyze one half-reaction, as has been observed in experiment.