Hydrogen sensing properties of Pd/SnO₂ nano-spherical composites under UV enhancement

The rapid and efficient detection of hydrogen plays an important role in the development of hydrogen energy. The response and selectivity of typical metal oxide semiconductor (MOS) sensors to low concentration hydrogen detection still need to be improved to meet the application of hydrogen. In this work, Pure SnO2 hollow spheres and different molar ratio of Pd decorated SnO2 spherical composites were synthesized by a facile template-free hydrothermal method. High response of 14.5 and fast response/recovery time of 2.2/22.4 s to 200 ppm hydrogen were achieved by 5.0 mol% Pd/SnO2 at 330 degrees C. The response to 200 ppm hydrogen was enhanced to 18.1 and the recovery time was also improved to 17.4 s with 10 mW/cm(2) UV irradiation. Especially, the response to inter-fering gases was inhibited with UV irradiation, which improved the selectivity of as-prepared sensors to hydrogen molecules. Linear dependence of the responses of as-prepared sensors on the hydrogen concentration was observed, indicating the great potential for quantitative detection of H-2 at ppm level. This work provides a facile route to synthesize porous spherical Pd/SnO2 for hydrogen detection and a reference for the future design of hydrogen detectors with UV irradiation.