Enhanced ethanol sensing of Ni-doped SnO_2 hollow spheres synthesized by a one-pot hydrothermal method

摘要

This work synthesized Ni-doped SnO_2 solid solutions of single-phase rutile structure by a facile one-pot hydrothermal method, and studied their gas sensing property. Hollow microspheres were obtained, and their morphology varied with Ni content. Sensors of Ni-doped SnO_2 were sensitive to presence of ethanol vapor, with a maximum response occurring at 260 ℃. For the optimum composition Ni/Sn-0.5 at.% (NS-0.5), a response of 28.9 was achieved at 260℃ for 100 ppm ethanol, which was twice that of pristine SnO_2. A linear dependence of the sensor response on the ethanol concentration was observed. The ethanol response remained almost constant during a 30-day measurement. Furthermore, the NS- 0.5 also exhibited excellent selectivity to ethanol against several common interfering gases. The ethanol sensing behavior and possible sensing mechanism was discussed in relation with the defect chemistry and microstructure.