Sensitivity enhancement for H2 gas detection using a SnO2–Ag2O–PdOx nanocrystalline system

Thick film H2 sensors were fabricated using SnO2 loaded with Ag2O and PdOx. The composition that gave highest sensitivity for H2 was in the wt.% ratio of SnO2:Ag2O:PdOx as 93:5:2. The nano-crystalline powders of SnO2–Ag2O–PdOx composites synthesized by sol–gel method were screen printed on alumina substrates. Fabricated sensors were tested against gases like H2, CH4, C3H8, C2H5OH and SO2. The composite material was found sensitive against H2 at the working temperature 125 °C, with minor interference of other gases. H2 gas as low as 100 ppm can be detected by the present fabricated sensors. It was found that the sensors based on SnO2–Ag2O–PdOx nanocrystalline system exhibited high performance, high selectivity and very short response time to H2 at ppm level. These characteristics make the sensor to be a promising candidate for detecting low concentrations of H2.