Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7708880 | International Journal of Hydrogen Energy | 2017 | 7 Pages |
Abstract
PtNb2O5 porous composite ceramics have been prepared from Pt and Nb2O5 particles through convenient pressing and sintering. Extraordinary room-temperature hydrogen sensing capabilities have been revealed for PtNb2O5 composite ceramics of 1â¯wt% Pt, including a sensitivity over 165, response time and recovery time of 7s and 39s, respectively, for 1% H2 in air. For 0.25% and lower concentrations of H2 in air, ultrafast recoveries, such as a recovery time of 8s for 0.04% H2 in air, are observed, which are singular for room-temperature hydrogen sensing. We further found a strong correlation between the resistance of PtNb2O5 composite ceramics and hydrogen concentration in ambient oxygen-free atmospheres, and a negative temperature dependence of hydrogen sensitivity, from which a hydrogen sensing mechanism rooted in hydrogen chemisorption on Nb2O5 has been established, while the ultrafast recoveries are explained in terms of a highly mobile and reactive state of chemisorbed hydrogen ions on Nb2O5.
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Authors
Pengcheng Li, Zhihong Xiong, Sheng Zhu, Mengye Wang, Yongming Hu, Haoshuang Gu, Yu Wang, Wanping Chen,