Nonanal gas sensing properties of platinum, palladium, and gold-loaded tin oxide VOCs sensors

We have investigated the nonanal sensing properties of Pt-, Pd-, and Au-loaded SnO2 (Pt, Pd, Au/SnO2) thick films. These films show a higher response to nonanal than a non-loaded SnO2 film, can detect several tens of ppb of nonanal and exhibit fast response and recovery times. Their nonanal sensing ability is improved by pretreatments, such as annealing temperature and aging. The resistance of these films in pure air depends on the working temperature, but the resistance in nonanal gas depends mainly on the film thickness. We suggest nonanal detection models for Pt, Pd, Au/SnO2 films with different film thicknesses, and determine the optimum film thickness for nonanal detection. (C) 2012 Elsevier B. V. All rights reserved.