SnO₂ NSs synthesized by hydrothermal method for Cl₂ sensing

Three-dimensional flower-shaped tin dioxide nanosheets (SnO₂ NSs) are prepared by magnetic stirring, hydrothermal reaction and ice bath rapid cooling using tin dichloride dihydrate as raw material. The same raw materials and preparation process are used to prepare the tin oxide nanoparticles (SnO₂ NPs) by natural cooling. The SEM characterization results show that SnO₂ NPs is about 50 nm, and it is composed of the irregular aggregation of nanoparticles. The SnO₂ NSs formed by rapid cooling show a three-dimensional flower-like morphology with well dispersion and interconnection. The reliable analysis of the growth mechanism of SnO₂ NSs is supplied through the literature investigation and material characterization results. Compared with SnO₂ NPs, the higher specific surface area of SnO₂ NSs makes it have stronger gas sensitive response value and selectivity to chlorine gas (Cl₂). The gas response of the SnO₂ NSs sensor is 223 to 5 ppm Cl₂ at 160 °C, and the detection limit is 0.0981 ppb by linear fitting of detection results at different concentrations. The SnO₂ NSs sensor maintains good stability with a fluctuation range of 11% in the relative humidity lower than 60% and exhibits excellent selectivity to Cl₂. A series of results demonstrate that SnO₂ NSs has large latent capacity as a gas sensor material for monitoring Cl₂. The possible mechanism of the preeminent performance of the SnO₂ NSs for Cl₂ detection is also deduced in detail.