Potentiostatic electrodeposition under light irradiation for preparation of highly photoactive Cu2O for water splitting applications

A novel approach based on the application of light irradiation during the electrodeposition is proposed to prepare Cu2O structures for photoelectrochemical water splitting. Potentiostatic deposition of Cu2O layers under irradiation and in the dark was carried out from lactate-stabilized copper sulfate on Ag coated glass substrates. The higher growth speed for light deposited samples is related to the contribution of photogenerated carriers to the reduction of electrolyte and electrodeposition of Cu2O. The light deposited samples exhibited higher photoresponse of 3.37 mA/cm(2) compared to 2.5 mA/cm(2) measured for dark deposited sample. Better carrier collection due to larger grain size and lower impurity incorporation are suggested as possible sources of the higher photoresponse for light deposited sample. The presented study demonstrates the light electrodeposition as an attractive way for preparation of highly photoactive Cu2O structures for water splitting applications.