Spherical-like SnS₂/CoSnO₃ microflowers with accelerated electrical conductivity for excellent gas-sensing...

The strategy of constructing suitable surface heterojunctions for promoting the adsorption and carrier transport capacity can be really conducive to the enhanced gas-sensing properties of SnS₂-based sensors. In the current work, uniform spherical-like SnS₂/CoSnO₃ microflowers with the accelerated electrical conductivity have been fabricated by the modified solvothermal method for effectively detecting triethylamine (TEA) at low operating temperatures. It is found that the response of SnS₂ microflowers to 100 ppm TEA is 4.02 at 120 °C, and the one of SnS₂/CoSnO₃ composites is up to 33.30 at 90 °C. The employment of ultraviolet (UV) light excitation plays a critical role in the reduction of optimal operating temperatures of SnS₂-based samples. For example, pure SnS₂ and SnS₂/CoSnO₃-2(Co/Sn molar ratios of 10 %) display the responses of 5.45 and 53.71-100 ppm TEA at 80 and 60 °C, together with the superior gas selectivity and the rapid response/recovery times of 70/282 and 50/98 s, respectively. Significantly, high response of 13.72 and superior gas stability of SnS₂/CoSnO₃ composites are observed even at room temperature. According to density functional theory (DFT) calculation, CoSnO₃ has higher electrical conductivity, contributing to accelerating the electron transmission rate between materials. The enhanced gas-sensing mechanism is mainly attributed to the available construction of SnS₂-CoSnO₃ heterojunctions with the increased carrier density and adsorption capacity of the materials under UV light irradiation. Both the actual detection verification and gas-sensing devices suggest that the sensors have wide prospects in the practical application of seafood storage evaluation.