Fabrication of H2S sensitive gas sensors formed of SnO2-Fe2O3 composite nanoparticles

Nanocomposites of metal oxide are considered promising candidates for developing novel gas sensors of exceptional performance. Composite SnO2-Fe2O3 nanoparticles are produced in this work by a modified sole-gel method, and tested for their gas response towards H2S gas in air. The nanoparticles are deposited on a printed substrate with interdigitated electrodes to produce gas sensor devices. Electrical characteristics of the produced devices are tested by means of impedance spectroscopy and revealed an activation energy of 0.13 +/- 0.01 eV. The sensors exhibit novel characteristics where they are functional at room temperature for low H2S concentration of 2.5 ppm. The practical production process, low power demand, enhanced sensitivity, and low recovery and response times of the fabricated sensors specify their potential for practical implementation for applications of portable gas sensors. Furthermore, the utilization of magnetic nanoparticles enables the recycling of nano-composites for further applications.