Reverse type I core - CuI /shell - CuO: A versatile heterostructure for photoelectrochemical applications

Here we report the synthesis of a core - Cul/shell - CuO nanostructure that depending on the applied potential works as photocathode or photoanode in neutral pH upon visible light irradiation. Under cathodic polarization, this material generates a stable cathodic photocurrent but functions as photoanode when anodic polarization is applied. In this new core-shell structure, the relevant position of the band edge potentials is pH-tunable and does not strictly follow the typical Nernstian dependence as by many semiconductor oxides, opening new directions in the nanoscale design of stable photoelectrodes for solar water splitting