High-sensitivity methanol gas sensor based on rare earth (Er, Tm and Ho) doping In2O3 material

In this paper, the pure and rare earth (RE=Er, Tm and Ho) doped In 2 O 3 materials have been synthesized with facile solvothermal method. The obtained powder samples were coated as sensing film on ceramic tube for fabricating methanol sensor. The gas-sensing performance of gas sensors were investigated in detail. The gas response was enhanced and the optimum operating temperature was decreased for RE doped In 2 O 3 materials. Among them, the Er/In 2 O 3 sample shown the better gas sensing properties, and the gas sensitivity has reached two times higher than that of the pure In 2 O 3 for 50 ppm methanol. The enhanced sensor response of the fabricated sensor has been ascribed to the increased surface basicity and lattice defects. Moreover, Er-doped In 2 O 3 sensor has exhibited super fast response time(2 s), good repeatability and selectivity. The enhancement of gas sensing performances could be attributed to a combination of the increased surface basicity and lattice defects.