Preparation of PdO-decorated NiO porous film on ceramic substrate for highly selective and sensitive H2S detection

Abstract

This work is to develop high-performance thin film gas sensors on the alumina ceramic substrate. Here, porous NiO films of about 2 μm were obtained by the simple electrochemical deposition technique. The NiO gas sensing thin films obtained by the in-situ growth overcomes the disadvantages of great thickness, material agglomeration, and uneven size of the conventional device structure. The films exhibit good uniformity, consistency, and reproducibility. The composition of the films and their porous morphological characteristics were demonstrated by SEM, XRD, AFM, and XPS characterization. The doping of PdO significantly enhanced the sensitivity and specificity selection of the NiO films for H2S gas. 2 wt% PdO/NiO thin film sensor exhibited a high response (515.27) and fast dynamic process at 155 °C for 10 ppm H2S. The outstanding gas-sensing performance of the thin film sensor is due to the doping of PdO and the porous structure of the film.