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Remarkably Enhanced Room-Temperature Hydrogen Sensing of SnO(2) Nanoflowers via Vacuum Annealing Treatment

In this work, SnO(2) nanoflowers synthesized by a hydrothermal method were employed as hydrogen sensing materials. The as-synthesized SnO(2) nanoflowers consisted of cuboid-like SnO(2) nanorods with tetragonal structures. A great increase in the relative content of surface-adsorbed oxygen was observ...

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Detalles Bibliográficos
Autores principales: Liu, Gao, Wang, Zhao, Chen, Zihui, Yang, Shulin, Fu, Xingxing, Huang, Rui, Li, Xiaokang, Xiong, Juan, Hu, Yongming, Gu, Haoshuang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5948644/
https://www.ncbi.nlm.nih.gov/pubmed/29570604
http://dx.doi.org/10.3390/s18040949
Descripción
Sumario:In this work, SnO(2) nanoflowers synthesized by a hydrothermal method were employed as hydrogen sensing materials. The as-synthesized SnO(2) nanoflowers consisted of cuboid-like SnO(2) nanorods with tetragonal structures. A great increase in the relative content of surface-adsorbed oxygen was observed after the vacuum annealing treatment, and this increase could have been due to the increase in surface oxygen vacancies serving as preferential adsorption sites for oxygen species. Annealing treatment resulted in an 8% increase in the specific surface area of the samples. Moreover, the conductivity of the sensors decreased after the annealing treatment, which should be attributed to the increase in electron scattering around the defects and the compensated donor behavior of the oxygen vacancies due to the surface oxygen adsorption. The hydrogen sensors of the annealed samples, compared to those of the unannealed samples, exhibited a much higher sensitivity and faster response rate. The sensor response factor and response rate increased from 27.1% to 80.2% and 0.34%/s to 1.15%/s, respectively. This remarkable enhancement in sensing performance induced by the annealing treatment could be attributed to the larger specific surface areas and higher amount of surface-adsorbed oxygen, which provides a greater reaction space for hydrogen. Moreover, the sensors with annealed SnO(2) nanoflowers also exhibited high selectivity towards hydrogen against CH(4), CO, and ethanol.