Al-doping induced formation of oxygen-vacancy for enhancing gas-sensing properties of SnO2 NTs by electrospinning

• Published in: Sensors and actuators. B, Chemical Vol. 198; pp. 62 - 69
• Main Authors: Wu, Jinjin, Huang, Qingwu, Zeng, Dawen, Zhang, Shunping, Yang, Lin, Xia, Dongsheng, Xiong, Zhongduo, Xie, Changsheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2014
• Subjects: Actuators; Al-doping; Detection; Electrospinning; Enhanced gas-sensing performance; Formations; Oxygen; Oxygen vacancy; Surface chemistry; Tin dioxide; Vacancies; Electrospinning; Al-doping; Enhanced gas-sensing performance; Oxygen vacancy
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2014.03.012

In this work, we report on the gas-sensing behavior of Al-doped SnO2 nanotubes (NTs) in order to evaluate the effect of Al on improved sensing performance and propose an oxygen-vacancy-dominating sensing mechanism of SnO2. The hierarchical mesoporous Al-doped SnO2 NTs are fabricated by simple electrospinning method and annealing treatment. Al-doping shows profound influence on the oxygen vacancy of SnO2 which changes as a function of Al/(Al+Sn) ratio and the oxygen vacancy exhibits a maximum value when the ratio is 8%. As a result, the gas-sensing response to formaldehyde varies following the oxygen vacancies. Oxygen vacancies at the surface of SnO2 facilitate oxygen adsorption and the formation of surface catalytic active O−O−, thus the gas response is remarkably enhanced. Furthermore, a new fundamental understanding toward the gas-sensing performance of oxygen-vacancy-dominating SnO2 is proposed.