TY - JOUR
T1 - Influence of oxygen vacancies on the performance of SnO2 gas sensing by near-ambient pressure XPS studies
AU - Liu, Lin
AU - Wang, Yingyi
AU - Guan, Kejie
AU - Liu, Yinhang
AU - Li, Yifan
AU - Sun, Fuqin
AU - Wang, Xiaowei
AU - Zhang, Cheng
AU - Feng, Simin
AU - Zhang, Ting
PY - 2023
Y1 - 2023
N2 - Modulation of oxygen vacancy (VO··) concentrations in SnO2 is an efficient strategy for improving its NO2 sensing performance. However, due to the complex reaction process between NO2 and adsorbed oxygen species on the surface of metal oxide, the role of VO·· is still unclear without in-situ characterization. Here, SnO2 nanowires (NWs) were synthesized via chemical vapor deposition method, and the VO·· concentration in SnO2 NWs was enhanced by removing adsorbed H2O on the surface of precursor during the growth process. The VO··-abundant SnO2 NWs exhibited large improvement in NO2 sensing performance with ultralow detection limit (2 ppb NO2) and high response value towards 1 ppm NO2 (49.5 at 50 °C). Near-ambient pressure X-ray photoelectron spectroscopy was used to reveal the in-situ sensing reactions occurred on the surface of SnO2 NWs. The results revealed that VO·· provided active sites for adsorption of oxygen species and confirmed the formation of NO. This work demonstrates an easy route to grow SnO2 NW with tunable VO·· concentration, and provides a direct evidence for deeper understanding of the effect of VO·· in sensing process.
AB - Modulation of oxygen vacancy (VO··) concentrations in SnO2 is an efficient strategy for improving its NO2 sensing performance. However, due to the complex reaction process between NO2 and adsorbed oxygen species on the surface of metal oxide, the role of VO·· is still unclear without in-situ characterization. Here, SnO2 nanowires (NWs) were synthesized via chemical vapor deposition method, and the VO·· concentration in SnO2 NWs was enhanced by removing adsorbed H2O on the surface of precursor during the growth process. The VO··-abundant SnO2 NWs exhibited large improvement in NO2 sensing performance with ultralow detection limit (2 ppb NO2) and high response value towards 1 ppm NO2 (49.5 at 50 °C). Near-ambient pressure X-ray photoelectron spectroscopy was used to reveal the in-situ sensing reactions occurred on the surface of SnO2 NWs. The results revealed that VO·· provided active sites for adsorption of oxygen species and confirmed the formation of NO. This work demonstrates an easy route to grow SnO2 NW with tunable VO·· concentration, and provides a direct evidence for deeper understanding of the effect of VO·· in sensing process.
KW - SnO nanowires
KW - Oxygen vacancy
KW - NO sensor
KW - Gas sensing mechanism
KW - Near-ambient pressure XPS
U2 - 10.1016/j.snb.2023.134252
DO - 10.1016/j.snb.2023.134252
M3 - Article
SN - 0925-4005
VL - 393
JO - Sensors and Actuators, B: Chemical
JF - Sensors and Actuators, B: Chemical
ER -