Interfacial Engineering of 2D-2D CdIn₂S₄/Ti₃C₂ Heterojunctions for Enhanced Photocatalytic Hydrogen Generation

Utilization of solar energy through wireless water-splitting technology offers a promising pathway toward a sustainable and environmentally conscious future. The rational design of 2D-2D heterojunctions leverages synergistic effects to optimize charge carrier dynamics, thereby boosting photocatalytic activity. In this study, well-engineered heterojunction Ti₃C₂/CdIn₂S₄ (TCIS) nanocomposites are synthesized via an in situ hydrothermal method and employed in photocatalytic hydrogen evolution (PHE). The hydrogen evolution rate of 9.799 mmol g^-1 h^-1 surpasses previously reported MXene-based materials, and is 26 times higher than pristine CdIn₂S₄, with an AQE of 6.4% under 420 nm light irradiation. Optimizing the electronic structure of active metal sites enhances rapid electron transport and synergistic proton reduction. With insights from DFT and KPFM studies, an efficient charge transfer pathway, with electron accumulation on Ti₃C₂ and depletion on CdIn₂S₄ are revealed. This study highlights the critical role of interfacial engineering in MXenes for accelerating water dissociation and presents a promising strategy for the development of high-performance materials for future energy applications.