Sensing behaviour of semconducting metal oxides for the detection of organophosphorus compounds

Abstract

Sensing behaviours of doped SnOa and ZnO elements have been investigated for the detection of organophosphorus compounds. Among the etements examined, SnOa- or ZnO-based elements doped with basic oxides such as CaO and MgO exhibit a promis~g sensing property to Dh4MP (dimethyl ~thylphosphonate). Reasonable sensitize can be obtained at concentrations of DMMP down to 44 ppb. The test gas was oxidixed upon exposure to the oxides. It has been suggested that the basic oxide additives are effective in aiding dissociative adsorption of DMMP on the oxide surface, thus facilitating the oxidation reaction of the test gas.