Preparation of Efficient MoS2 Photocatalysts for Hydrogen Generation Through Sulfurization of MoO3 Thin Films via Chemical Vapor Deposition

The transition to clean and renewable energy sources is of prime importance in addressing environmental challenges related to the consumption of fossil fuels. Hydrogen, being a clean fuel with a high energy density, has huge potential, especially when it can be obtained through solar-driven PEC water splitting. Herein, MoS2 photocatalysts were synthesized by sulfurizing MoO3 thin films, using a CVD technique. The deposited MoO3 films by thermal evaporation at 450 °C were further sulfurized at 500 °C, 550 °C, and 600 °C. XRD results confirmed the successful conversion of MoO3 into MoS2. The optical properties showed a bandgap reduction from 2.50 eV to 1.30 eV, which leads to better absorption of light in the visible region.The photoelectrochemical experiment shows that the S-MoO3-600 °C thin film has the best performance, and the solar-to-hydrogen conversion efficiency reaches 0.11385% at an applied bias of 1.0 V versus Ag/AgCl, which is about 189 times higher than that of the pristine MoO3 thin film.