Construction of hierarchical Ti3C2Tx MXene/ZnIn2S4 heterostructures for efficiently photocatalytic reduction of Cr(VI) under visible light

Abstract

• MXene/ZnIn 2 S 4 composites were constructed via one-step water bath process. • MXene/ZnIn 2 S 4 composites exhibit excellent photocatalytic activities and stability. • MXene/ZnIn 2 S 4 composites promote the separation of electron-hole pairs effectively. • The mechanism of photocatalytic activity for MXene/ZnIn 2 S 4 composites is evaluated. Facilitating photogenerated carriers separation as well as broadening visible-light driven range play important roles in enhancing photocatalytic activity of catalysts. The hierarchical heterostructured photocatalysts have attracted increasing attention due to unique structure and high photocatalytic performance in photocatalytic applications. Here, the hierarchical Ti 3 C 2 T x MXene/ZnIn 2 S 4 heterostructures were successfully synthesized by a simple one-step method, which can serve as an efficient catalyst for photocatalytic reduction of potassium dichromate (Cr(VI)) and degradation Methyl orange (MO) under visible light. The few-layered MXene acts as a charge carrier, enhancing the catalytic activity of the zinc indium sulfide (ZnIn 2 S 4 ) by promoting the carrier transport and the redox reactions. The strong interactions between ZnIn 2 S 4 and the MXene are beneficial to the high utilization of solar energy, enhanced charge separation ability, excellent photocatalytic capability and stability. The hierarchical Ti 3 C 2 T x MXene/ZnIn 2 S 4 heterostructures exhibit promising photocatalytic ability for Cr(VI) reduction and MO degradation with high degradation rate of 93.4% and 96.9% within 45 min under simulated visible-light irradiation, respectively. This work provides a novel design idea for fabricating the hierarchical heterostructured materials to solve the environmental pollution problems.