Study of influence of palladium additives in nanosized tin dioxide on sensitivity of adsorption semiconductor sensors to hydrogen

Nanosized materials based on tin dioxide with palladium additives were synthesized to produce gas sensitive layers of the adsorption semiconductor hydrogen sensors. The synthesis of nanosized Pd-containing materials based on SnO2 was carried out by a sol–gel method using ethylene glycol as a solvent. Influence of palladium additives on sensitivities of the sensors to H2 and catalytic properties of the corresponding Pd-containing sensor materials in reaction of H2 oxidation were studied. It was shown that the sensor properties depended on catalytic processes of H2 oxidation on the sensor surfaces. The most active hydrogen sensor contains only 0.016 wt% Pd and at its optimal operating temperature demonstrates a fast response time (3 s) and quick recovery time (7 s) comparatively to reported earlier hydrogen sensors. The proposed fast-acting sensors are capable to measure hydrogen in a wide range of its concentrations (6–800 ppm H2) at relatively low operating temperatures.