Metal Oxide Based Heterojunctions for Gas Sensors: A Review
Shulin Yang,
Gui Lei,
Huoxi Xu,
Zhigao Lan,
Zhao Wang,
Haoshuang Gu
Affiliations
Shulin Yang
Hubei Key Laboratory for Processing and Application of Catalytic Materials, School of Physics and Electronic Information, Huanggang Normal University, Huanggang 438000, China
Gui Lei
Hubei Key Laboratory for Processing and Application of Catalytic Materials, School of Physics and Electronic Information, Huanggang Normal University, Huanggang 438000, China
Huoxi Xu
Hubei Key Laboratory for Processing and Application of Catalytic Materials, School of Physics and Electronic Information, Huanggang Normal University, Huanggang 438000, China
Zhigao Lan
Hubei Key Laboratory for Processing and Application of Catalytic Materials, School of Physics and Electronic Information, Huanggang Normal University, Huanggang 438000, China
Zhao Wang
Hubei Key Laboratory of Ferro & Piezoelectric Materials and Devices, Faculty of Physics and Electronic Sciences, Hubei University, Wuhan 430062, China
Haoshuang Gu
Hubei Key Laboratory for Processing and Application of Catalytic Materials, School of Physics and Electronic Information, Huanggang Normal University, Huanggang 438000, China
The construction of heterojunctions has been widely applied to improve the gas sensing performance of composites composed of nanostructured metal oxides. This review summarises the recent progress on assembly methods and gas sensing behaviours of sensors based on nanostructured metal oxide heterojunctions. Various methods, including the hydrothermal method, electrospinning and chemical vapour deposition, have been successfully employed to establish metal oxide heterojunctions in the sensing materials. The sensors composed with the built nanostructured heterojunctions were found to show enhanced gas sensing performance with higher sensor responses and shorter response times to the targeted reducing or oxidising gases compare with those of the pure metal oxides. Moreover, the enhanced gas sensing mechanisms of the metal oxide-based heterojunctions to the reducing or oxidising gases are also discussed, with the main emphasis on the important role of the potential barrier on the accumulation layer.
