Liquefied petroleum gas sensing properties of sprayed nanocrystalline zinc oxide thin films

Abstract

A ZnO nanocrystalline detector for the liquefied petroleum gas (LPG) species is described. The nanocrystalline ZnO thin films were synthesized using a spray pyrolysis chemical deposition method and applied for structural elucidation, morphological evolution studies. The films are nanocrystalline (about 32-39 nm crystallites sizes), hexagonal wurtzite crystal structure with c-axis orientation along (0 0 2) plane. The lattice stress developed with increase in temperature ensures decrease in lattice parameters. Enhanced band gap of the film with heat treatment is a key factor for generating the active sites for the sensing of gas species. The LPG sensing performances of the ZnO films have been investigated at various concentrations at operating temperatures varying from 150 to 450 degrees C. A possible reaction mechanism of LPG sensing has also been proposed. (C) 2012 Elsevier B.V. All rights reserved.