La/SnO2 nanoparticles: Hydrothermal synthesis, structure, and sensing performance in a high relative humidity environment

In this work, a simple one-step hydrothermal synthesis of La doped SnO 2 nanocomposites was studied. The structure, morphology, specific surface area, and chemical composition were determined by XRD , SEM, BET, and XPS techniques. The gas sensing performance of SnO 2 and La/SnO 2 nanocomposites with varied La doping dosages on n-butanol gas was systematically investigated. The results manifested that under the testing environment (50 % relative humidity and 30 °C), La doped SnO 2 nanocomposite sensor presented high response (69), excellent selectivity, good repeatability and long-time stability to n-butanol gas at 160 °C. Especially, the 7 mol% La doped SnO 2 sensor displayed a 5.9 times higher response to 50 ppm n-butanol than the SnO 2 sensor. In comparison with bare SnO 2 , La doping increased the band gap value of 7 mol% La/SnO 2 nanocomposite by 6.23 %, decreased particle size by 11.83 %, and increased the oxygen defect concentration by 6.07 %. Due to the synergistic effect of the above factors, the gas sensing performance of La doped SnO 2 nanocomposites towards n-butanol gas was enhanced. Therefore, La doped SnO 2 nanocomposites might be a potential gas sensing material for monitoring n-butanol gas at relatively high humidity.