Triptycene-Based Polymer Embedded in ZnIn₂S₄ to Construct a Hierarchical Heterostructure for Efficient Photocatalytic Hydrogen Evolution

Abstract

Development of promising photocatalysts with a synergistic effect for hydrogen generation holds paramount significance for solving the global energy problem. Herein, we rationally design a hierarchical heterostructure in which a triptycene covalent polymer (TCP) is grown in situ on ZnIn2S4 through a Suzuki coupling reaction. Assorted experimental results demonstrate that amorphous TCP with a high BET surface area (903 m2 g–1) is embedded on 2D ZnIn2S4 nanoflakes by a self-assembly process, thus indicating the unique hierarchical architecture, high surface area, and large interface contact area. Based on the favorable heterojunction structure, ZnIn2S4/TCP-2 yields the highest visible-light-derived hydrogen production rate of 1432.8 μmol h–1 g–1, which is more than 9 times that of bare ZnIn2S4. The enhanced hydrogen evolution of ZnIn2S4/TCP comes from the enhanced absorption of visible light, a well-matched band structure, and effective electron transfer. This work provides a promising approach to enhance the solar hydrogen production performance of metal sulfide by using a triptycene covalent polymer.