MOF templated to construct hierarchical ZnIn2S4-In2S3 hollow nanotube for enhancing photocatalytic performance

Abstract

3D (Three-dimensional) hollow porous structured materials received a lot of attention due to their significant benefits in photocatalytic reactions. In this study, 3D ZnIn2S4-In2S3 hollow hierarchical porous nanotubes were synthesized by a one-step MOF (metal–organic framework) templating strategy as efficient catalysts for photocatalytic hydrogen evolution in water. The dynamic process between the internal collapse of In-MIL-68 and the growth of ZnIn2S4 crystals with attached outer edges led to the one-step in situ preparation of hollow ZnIn2S4-In2S3 heterojunction catalysts. Crucially, In-MIL-68 simultaneously induced the formation of In2S3 hollow porous nanotubes and the construction of ZnIn2S4-In2S3 hierarchical heterojunction with ultrathin nanosheets. The optimal photocatalytic efficiency was obtained by adjusting the relative composition of the two-component heterojunction, and the optimized ZnIn2S4-In2S3-10 showed hydrogen evolution efficiency of 5.01 mmol·h−1·g−1 under visible light irradiation in the absence of co-catalysts and a high AQY (the apparent quantum yield) of 16.23 % at 420 nm, which was noticeably higher than the photocatalytic efficiency of the one-component and two-step synthesized In2S3-ZnIn2S4. Both theoretical and experimental results demonstrated that the construction of heterojunction and the forming of hollow porous nanotubes enhanced visible light absorption and promoted the separation and transfer of photogenerated carriers, thereby increasing the photocatalytic activity of the prepared materials. Meanwhile, ZnIn2S4-In2S3 hierarchical hollow nanotubes exhibited good stability and reusability, offering a new way to fabricate MOF-based hollow hierarchical photocatalysts.