2D/2D NiPS3/g-C3N4 heterojunctions for photothermal-assisted photocatalytic hydrogen evolution

Abstract

The process of Photocatalytic Hydrogen Evolution (PHE) represents a reliable method for addressing the energy crisis. In this work, a self-assembly method was performed to combine 2D NiPS₃ (NPS) nanosheets (Ns) with 2D C₃N₄ (CN) Ns to prepare NPS Ns/CN Ns (NPCN) 2D/2D heterojunctions with intimately interfacial contact between these two components. Compared to CN Ns, NPCN photocatalysts possess wide-spectrum light absorption regions, excellent light-to-thermal energy effect, electron mobility, charges transfer, and abundant surface active site, thus leading to the enhanced PHE performance for NPCN composites in natural seawater and simulated seawater. Meanwhile, the negative effect of the added various ions on the PHE performance was revealed over 2-NPCN using different typical aqueous solutions. The first-principle calculations and experimental analysis were performed to gain a deep understanding of the underlying mechanisms responsible for the exceptional HER activity over NPCN composites. Drawing from the characterization and DFT calculation results, a photothermal-assisted PHE mechanism was proposed over NPCN composites. This work provides a strategy for the design and synthesis of efficient, stable and highly active g-C₃N₄-based heterojunctions.