Trace gas detection using nanostructured graphite layers

Abstract

Nanostructured graphite (NG) has been investigated as a sensing material using a highly sensitive potentiometric detection technique. NO2 concentration down to 60ppb was detected in ambient conditions using NG functionalization layer. Simultaneous current and surface work function (SWF) change transients measured using NG functionalization layer reveal much shorter response time for the later, which is attributed to its dependence solely on surface molecular adsorption. The gradient of SWF with respect to the current transient was found to be independent of gaseous concentration and fraction of preoccupied surface states.