Photoelectrochemical water oxidation properties of Mo-doped CuWO4: Effect of p-type sulfide loading and annealing

[Display omitted] •Mo-doped CuWO4 showed a 47-times higher photo-current density than pristine CuWO4.•MoS2 loading led to a significant p-n heterojunction effect for CuWO4 electrode.•MoS2/Mo:CuWO4 showed high stability of photoelectrode.•The annealed MoS2/Mo:CuWO4 is expected to be used as an oxygen-evolution electrode. Photoelectrochemical water splitting has received much attention from the perspective of the production of hydrogen as a next-generation source of energy. Herein, we focus on CuWO4 as a photoanode for water splitting because it is highly responsive to visible light. Mo doping led to longer wavelength shift of absorption edge in UV–vis absorption spectrum. Linear sweep voltammetry revealed that Mo-doped CuWO4 showed a 47-times higher photo-current density than pristine CuWO4 due to enhanced visible light absorption efficiency. The photo-current density of the Mo-doped sample also doubled when loaded with p-type MoS2.