Theoretical study on the photocatalytic properties of 2D InX(X = S, Se)/transition metal disulfide (MoS2 and WS2) van der Waals heterostructures.

Harvesting solar energy for artificial photosynthesis is an emerging field in alternative energy research. In this work, the photocatalytic properties of InX(X = S, Se)/transition metal disulfide (MoS2 and WS2) van der Waals heterostructures have been investigated. The calculation results indicate that these heterostructures exhibit improved photocatalytic performance over that of isolated InX or transition metal disulfide monolayers. The studied heterostructures all have type-II band alignment with holes and electrons located at the TMD and InX side, respectively. This facilitates the spatial separation of photogenerated carriers and improves the photocatalytic efficiency. The carrier mobility of the designed heterostructures can be boosted compared with the isolated monolayers, thus enhancing the carrier transport properties. Moreover, the strain-tuned heterostructures can prominently manipulate the light-harvesting capability especially from the visible light to infrared light range. Among the studied heterostructures, InSe/MoS2 with the suitable band edge positions, excellent transport properties and strain tolerance, and the lowest overpotential for oxygen evolution, stands out as the most promising candidate for photocatalytic applications. This work opens an avenue for the design of highly efficient heterostructure photocatalysts for solar-to-energy applications.