Low-temperature hydrogen detection sensor based on CeO₂ -DOPED SnO₂

Cost-effective H₂ detection sensors based on pure and CeO₂ (0.5 at%, 1 at%, 1.5 at%, 2 at%, 3 at%, 4 at%)-doped SnO₂ semiconductor oxides with both high moisture resistance and low operation temperature were prepared by a simple method. The crystal phase, morphology, and chemical composition of the obtained CeO_2-doped SnO₂ sample were analyzed and related with the sensing properties. The results show that the H₂ sensing performance of pure SnO₂ gas sensor can be improved a lot by CeO₂ doping. In particular, gas sensors based on 2 at% CeO₂/SnO₂ exhibited the greatest performance: high responsiveness at 160 °C (23.7 for 50 ppm hydrogen), about 3 times higher than pure SnO₂ sensor (6.9); short response and recovery time (2 and 9 s); good repeatability and long-term stability without any change after 30 days (23.7 for 50 ppm hydrogen), good selectivity, and moisture resistance. Finally, the function of CeO₂ on SnO₂ gas sensor for H₂ detection is discussed.