Harnessing Ti3C2-WS2 nanostructures as efficient energy scaffoldings for photocatalytic hydrogen generation

Abstract

Two-dimensional (2D) Ti₃C₂ MXene have attracted a lot of attention as frontier materials for the development of effective photocatalysts that can transform solar energy into chemical energy, which is essential for water splitting to produce hydrogen. Here, we use first principle calculations to understand the structural, electronic, and vibrational features of a novel heterostructure comprising a monolayer of tungsten disulfide (WS₂) and titanium carbide (Ti₃C₂) MXene. Our theoretical calculations revealed that the Ti₃C₂ maximizes the interfacial contact area with the WS₂ monolayer creating a strong p–-d hybridization for the WS₂/Ti₃C₂ heterostructure. As a result, a well-constructed Schottky junction is enabled, facilitating an interconnected electron pathway across the interface which is conducive for an efficient photocatalytic performance. Further, the experimentally designed WS₂/Ti₃C₂ heterostructure and its photocatalytic activity based on the synergistic action between MXene and WS₂ is investigated. Optical properties calculated are compared with experimental data derived from UV–Visible spectroscopy. The excellent conductivity and stability along with the light absorption in the visible region of WS₂/Ti₃C₂ enhances the photocatalytic performance approaching photocurrent densities of ∼33 and 120 μA/cm² in the HER and OER region, respectively. Overall, the present research not only improves our understanding of WS₂/Ti₃C₂ heterostructure for an improved photocatalytic activity, but also provides an efficient method toward sustainable hydrogen production.