Enhanced ethanol sensing of Ni-doped SnO2 hollow spheres synthesized by a one-pot hydrothermal method

This work synthesized Ni-doped SnO2 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 SnO2 were sensitive to presence of ethanol vapor, with a maximum response occurring at 260 degrees C. For the optimum composition Ni/Sn = 0.5 at.% (NS-0.5), a response of 28.9 was achieved at 260 degrees C for 100 ppm ethanol, which was twice that of pristine SnO2. 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. 2016 Elsevier B.V. All rights reserved.