Enhanced H₂ gas sensing performances by Pd-loaded In₂O₃ microspheres

Hydrogen (H₂) energy, as a clean energy source, has high energy density and durability, while H₂ is flammable and explosive, which requires strict safety technology measures to ensure the safety of high-pressure storage transportation. Therefore, the development of sensitive sensors is needed. In this study, In₂O₃ microspheres with different Pd loadings were fabricated by hydrothermal method. Compared with the pristine In₂O₃ gas sensor, the optimal operating temperature of the In₂O₃ sensor is reduced from 160 ℃ to 80 ℃ after loading Pd. Among the prepared Pd/In₂O₃ gas sensors, the response value of the 2 at% Pd/In₂O₃ sensor towards 1000 ppm H₂ is 50.743 at 80 ℃. The response/recovery time is 80 s/235 s. The improved H₂ sensing performance can be ascribed to the chemical and electron sensitization of Pd, and the formation of PdO, PdH_x. This study shows that Pd-loaded In₂O₃ can effectively reduce the optimal operating temperature and enhance the response value for detecting H₂ in the range of 5-5000 ppm. Therefore, this sensor has good application prospects for detecting H₂ at low temperatures.