Transformation synthesis of heterostructured SnS2/ZnS microspheres for ultrafast triethylamine detection.

• SnS 2 /ZnS heterojunction was successfully obtained via transforming ZnSn(OH) 6 precursor. • The synthesized SnS 2 /ZnS microspheres were composed of ultrathin nanoflakes. • The sensor of SnS 2 /ZnS exhibited ultrafast respose/recovery time (2/8 s) to 50 ppm TEA. • The SnS 2 /ZnS sensor showed excellent selectivity and antihumidity ability. • The sensing mechanism and humidity effects were discussed in detail. At present, gas sensors have promising prospects in terms of gas monitoring. Heterostructure with high carrier transport property is an alternative strategy to enhance the gas sensitivity. Herein, we directly transformed ZnSn(OH) 6 microspheres to obtain SnS 2 /ZnS heterostructures through a low-cost hydrothermal treatment. Hierarchical SnS 2 /ZnS flowerlike microspheres consisting of ultrathin nanoflakes subunits were successfully synthesized without any impurities. The more attractive finding is the great improvement of triethylamine gas-sensing properties of the SnS 2 /ZnS composite compared to the pure SnS 2 at 180 °C. Especially, the proposed SnS 2 /ZnS sensor demonstrates ultrafast responding and recovering time (2/8 s) to 50 ppm TEA. Such significantly enhanced sensing properties can be ascribed to the merit of heterojunction and high specific surface area provided by flakes-assembled flowerlike structure. Moreover, the convenient synthetic route paves the way to the future design of various heterojunctions for diverse gas detection. [ABSTRACT FROM AUTHOR]