Ultrasensitive gas sensor based on 3D assembled SnS2/SnO2 nanoflowers for NO2 detection at room temperature

Nanostructures of SnO 2 and SnS 2 have been extensively studied for gas sensor application, but individual material faces some limitations such as low detection limits, poor selectivity, and high-power consumption. Nanohybrids of SnO 2 and SnS 2 are expected to achieve high sensing response at low temperatures, but their synthesis is challenging due to the complex processes. Herein, we synthesized SnS 2 flower-like nanostructures decorated with SnO 2 nanoparticles for enhanced gas-sensing performance via one-pot hydrothermal method using tin (IV) chloride pentahydrate and thiourea as precursors. By controlling the ratio of precursors, two phases of SnO 2 and SnS 2 were simultaneously obtained. The functionalizing effect of SnO 2 nanoparticles on the morphology, structure and gas-sensing properties of SnS 2 was systematically studied. Additionally, the impact of moisture on the sensing behaviors is investigated meticulously. On top of that, the synergetic effect of n-n SnS 2 /SnO 2 junction is explicated in gas-sensing mechanism. These findings offer a feasible way to construct scalable and effective NO 2 gas sensors for real-world applications.