Chapter 8: Transition Metal Dichalcogenide-based Photocatalyst Materials for Hydrogen Production

Transition metal dichalcogenides (TMDs) are an emerging class of two-dimensional materials with great potential for photocatalytic applications owing to their unique electronic and optical properties. TMDs possess a layered structure with strong in-plane covalent bonds and weak van der Waals interactions between the layers. This structure allows efficient charge transfer and separation, making TMDs efficient photocatalysts for various applications, including photocatalytic hydrogen production. TMDs have a distinct band structure with a direct bandgap, which enables the efficient absorption of visible light. TMDs can be synthesized using various methods, including chemical vapor deposition, exfoliation, solvothermal, and hydrothermal syntheses. To enhance the photocatalytic efficiency of metal oxide semiconductors, TMDs have been used as cocatalysts and are an alternative cocatalyst to costly noble metals, such as platinum and palladium. TMDs present additional active sites where hydrogen molecules can be adsorbed and activated. Several strategies have been employed to enhance the photocatalytic performance of TMDs by coupling with other semiconductors to create heterostructures and composites. Despite the great potential of TMDs, their use as photocatalysts faces challenges, including limited visible light absorption, relatively low carrier mobility, etc. This chapter discusses the utilization of MoS₂-, WS₂-, ReS₂-, and NiS₂-based photocatalysts for photocatalytic hydrogen production.