A novel two-dimensional transition metal dichalcogenide as water splitting photocatalyst with excellent performances

With the rising demand for renewable energy, photocatalysts are considered the most promising solution to harness solar energy, and the search for photocatalysts with excellent performances remains an urgent task. Here, based on density functional theory (DFT), the photocatalytic properties of MoWS₄ are systematically investigated. The MoWS₄ monolayer and bilayer are demonstrated as semiconductors with indirect band gaps of 2.01 and 1.48 eV. Moreover, they exhibit high and anisotropic light absorption coefficients of up to ∼10⁵ cm^-1 in the visible-ultraviolet region. The intrinsic band edge positions could fully satisfy the redox potentials of water without any external adjustment. The electron mobility of MoWS₄ monolayer is 557 cm² V^-1s^-1, which is seven times higher than MoS₂ monolayer. Hence, MoWS₄ can be regarded as a promising 2D photocatalyst candidate for water splitting.