SnO2 (n)-NiO (p) composite nanowebs: Gas sensing properties and sensing mechanisms

Aiming to optimize SnO2-NiO nanocomposite sensors for detection of hazardous gases, a series of xSnO(2)(1-x) NiO composite nanowebs with different compositions (x = 0.1, 0.3, 0.5, 0.7, and 0.9) were synthesized using an electro spinning process. The formation of long and continuous SnO2-NiO nanowebs was verified. Depending on the composition, xSnO(2)-(1-x) NiO composite nanowebs showed either n-type (SnO2-rich composition) or p-type (NiO-rich composition) gas-sensing behavior. The best sensing performance was obtained for the nanowebs of 0.5SnO(2)-0.5NiO. The presence of plenty of p-n heterojunctions along with the high oxygen adsorption property of NiO were the main reasons for the high response to the NO2 and C6H6 gases at this optimized composition. (C) 2017 Elsevier B.V. All rights reserved.