Chemoresistive sensor for hydrogen using thin films of tin dioxide doped with cerium and palladium

This work reports on the development of thin films of SnO2 doped with cerium and palladium and shows them to be viable materials for chemoresistive sensing of hydrogen (H2). The sensing material was synthesized by a hydrothermal route and with different weight percentage loadings of the dopants. The structural and morphological features were investigated by X-ray diffraction, field emission scanning electron microscopy, FTIR and X-ray photoelectron spectroscopy. Thin films were fabricated by spin coating on a ceramic substrate. The change in the resistance of the film was measured as a function of the concentration of H2. The results show that the amount of loading with Ce and Pd has a large effect on the performance. The Ce doped nanocomposite sensor has a lower detection limit of 50 ppm of H2 and covers the 50 to 500 ppm H2 concentration range if operated at the optimum temperature of 200 °C and a working voltage of 5 V.