A classification and ranking system on the H2 gas sensing capabilities of nanomaterials based on proposed coefficients of sensor performance and sensor efficiency equations

Abstract

A coefficient of performance is defined based on the traditional definitions of response, S, of a chemoresistive sensing material to a specific gas from resistance–time data. The new definition not only considers the S(sub response) and S(sub recovery) but also the temperature, T, and the relative humidity, H, at which the sensor operates and the response time, t(subres), and recovery time, t (sub rec). Resistance–time data at various temperatures in a H2 atmosphere for six samples of different materials, including WO(sub3) nanoparticles, SnO(sub2) nanoparticles, SnO(sub2) nanoparticles mixed with carbon nanotubes, TiO(sub2) nanorods, TiO(sub2) nanotubes and VO(sub2) nanobelts, are presented in this report. The VO(sub2) nanobelts were the best sensing materials when these materials were ranked according to the temperatures at which they operate; however, the SnO(sub2) nanoparticles are the superior sensing materials when they are ranked by the defined coefficient of performance.