Interface passivation to overcome shunting in semiconductor-catalyst junctions

High-performance mesoporous hematite photoanodes modified with a conductive water oxidation catalyst, Ni0.75Fe0.25OxHy, for photoelectrochemical water oxidation are limited by shunting. We present a general method to overcome shunting via the selective electrodeposition of a thin poly(phenylene oxide) (PPO) insulating layer onto the exposed transparent conductive oxide substrate following catalyst deposition.