PdAg alloy modified SnO2 nanoparticles for ultrafast detection of hydrogen
Xiaoning Meng, Mingshu Bi, Wei Gao
Abstract
Hydrogen is rapidly applied worldwide as a carbon-free energy carrier, while the rapid detection of leaked hydrogen concentration is still a challenging problem. A sensitive material based on PdAg alloy modified SnO 2 nanoparticles for rapid detection of hydrogen is successfully prepared. The Pd 4 Ag/SnO 2 based sensor displays ultrafast response rate (1 s @ 1000 ppm), high response value (2843 @ 1000 ppm) and outstanding selectivity to hydrogen. To date, Pd 4 Ag/SnO 2 prepared in this study exhibits the fastest response rate among the bimetal modified semiconductor metal oxide hydrogen sensors reported. Furthermore, PdAg alloy is used to construct a co-sensitizer with low activation energy , further displaying a reduced operating temperature. Detailed sensing mechanism demonstrates that the enhanced hydrogen sensing capability of PdAg/SnO 2 is related to the synergistic effect of PdAg alloy, including the catalytic sensitization triggered by Pd and Ag as well as abundant chemisorbed oxygen introduced by PdAg alloy. The PdAg/SnO 2 based sensor with superior hydrogen sensing properties provides the possibility for development of a novel rapid response hydrogen sensor.