Surface customization of SnO2 thick films using RuO2 as a surfactant for the LPG response

Thick films of pure, RuO2-doped and surface-customized SnO2 were prepared using screen-printing technique. The gas sensing properties of these films were systematically studied. The gas response of surface-ruthenated (surface customized using RuO2) SnO2 is observed to be larger than the responses of pure and RuO2-doped SnO2 to 1000 ppm LPG. The surface species (RuO2) exerts considerable influence on the gas response by modulating the adsorption characteristics. The selectivity for LPG against H2, NH3, CO2 and H2S gases, response time and recovery time of the sensor were also studied. The results are interpreted.