The Surface Scattering-BasedDetection of Hydrogen in Air Using a Platinum Nanowire.

The performance of a single platinum (Pt) nanowire fordetecting H2in air is reported. A Pt nanowire shows noresistance change upon exposure to H2in N2,but H2exposure in air causes a reversible resistance decreasefor H2concentrations above 10 ppm. The amplitude of theresistance change induced by H2exposure and the time rateof change of the nanowire resistance both increased with increasingtemperature from 298 to 550 K. This resistance decrease of the Ptnanowire in the presence of H2results from reduced electrondiffuse scattering at hydrogen-covered Pt surfaces as compared withoxygen-covered platinum surfaces, we hypothesize. The properties forthe detection of H2in air of single Pt and Pd nanowiresof similar size are compared in this study. Pt nanowires have a limit-of-detectionfor H2(LODH2) of 10 ppm; 3 ordersof magnitude lower than for Pd nanowires of the same size, as wellas a response time that is 1/100th of Pd for [H2] ≈1%. [ABSTRACT FROM AUTHOR]