Enhanced photoelectrochemical activity of MoS2-decorated ZnO nanowires electrodeposited onto stainless steel mesh for hydrogen production

A novel MoS2-coated ZnO heterostructure grown onto stainless steel substrate was successfully realized via an original two-step electrodeposition process. The X-ray diffraction revealed the mixed wurtzite and hexagonal structures of both ZnO and MoS2 for 30 min as an optimized MoS2 deposition time. The optical properties studied through UV-visible diffuse reflectance and photoluminescence show that the incorporation of MoS2 to the ZnO nanowires further extends the light absorption. More importantly, from PEC measurements, the obtained heterostructure exhibits the highest photocurrent density at a bias of 0 V with improved stability and provides the highest value of solar-to-hydrogen energy efficiency eta(%) compared to bare ZnO. As a result, the MoS2 acts as a cocatalyst to suppress the electron-hole pairs recombination and prevents the photocorrosion of ZnO as proposed in the possible transfer mechanism within the MoS2/ZnO heterostructure. These findings may provide more insights into the design of highly efficient MoS2-coated ZnO photoanodes for solar energy-to-hydrogen generation.