Contrasting room-temperature hydrogen sensing capabilities of Pt-SnO2 and Pt-TiO2 composite nanoceramics
SnO2, nanoceramics, sensors, hydrogen, room-temperature
ABSTRACT Contrasting room-temperature hydrogen sensing behaviors have been revealed for Pt-TiO2 and Pt-SnO2 composite nanoceramics. In the case of the Pt-TiO2 nanoceramics, the ultrahigh hydrogen sensitivities are lost abruptly when the oxygen/hydrogen concentration ratio in ambient atmosphere reaches a critical value. However, in the case of the Pt-SnO2 nanoceramics, such a phenomenon does not occur, and the extraordinary room-temperature hydrogen sensing capabilities are observed in the presence of oxygen in air. Our combined experimental and theoretical investigations establish a unified mechanism for both the systems, which is rooted in hydrogen chemisorption on the surface and interstitial lattice sites of SnO2 and TiO2; the difference in stability of the chemisorbed hydrogen on SnO2 and TiO2 is considered responsible for the contrasting hydrogen sensing capabilities. The central findings are helpful in enriching our microscopic understanding of hydrogen interaction with various metal oxide semiconductors (MOSs) at room temperature in varying mixed gaseous concentrations, and they could be instrumental in developing reliable room-temperature hydrogen sensors based on bulk MOSs.
Tsinghua University Press
Yao Xiong,Wanping Chen,Yesheng Li,Ping Cui,Shishang Guo,Wei Chen,Zilong Tang,Zijie Yan,Zhenyu Zhang, Contrasting room-temperature hydrogen sensing capabilities of Pt-SnO2 and Pt-TiO2 composite nanoceramics. NanoRes.2016, 9(11): 3528–3535