Fabrication of solar-driven hierarchical ZnIn2S4/rGO/SnS2 heterojunction photocatalyst for hydrogen generation and environmental pollutant elimination

Abstract

As a solution to the energy crisis and environmental pollution, photocatalytic production of hydrogen (H2) in conjunction with organic pollutant degradation has received broad attention. As a proof of concept, ternary ZnIn2S4/rGO/SnS2 heterojunction photocatalyst with high performance and stability were prepared by a one-step hydrothermal method. Experimentally, the composite has been examined for its microstructures and morphologies, as well as its photocatalytic generation of hydrogen (H2) and tetracycline (TC) degradation performance. The results indicate that ZnIn2S4/rGO/SnS2 heterojunctions possessed the higher photocatalytic activities towards hydrogen production and TC degradation ability (7847 μmol g-1h−1, 96.5%) than that of SnS2 (756 μmol g-1h−1, 60.9%), SnS2/rGO (1680 µmol g-1h−1, 69%), ZnIn2S4 (540 μmol g-1h−1, 64.1%), ZnIn2S4/rGO (1242 μmol g-1h−1, 75%), and ZnIn2S4/SnS2 (4654 μmol g-1h−1, 84%), respectively. Moreover, it demonstrated excellent reusability and stability after five consecutive cycles for both H2 generation and TC photodegradation. The intermediates of the photodegradation process were identified by GC–MS methods. Due to the hexagonal and layer structured material and the synergetic effect, the photocatalytic efficiency is greatly improved in the ZnIn2S4/rGO/SnS2 heterojunction photocatalyst, which also enhanced the separation of charge carriers. In this study, we developed a non-toxic, low-cost, highly efficient and recyclable photocatalyst for H2 production and TC degradation.