Effects of rare earth element doping on the ethanol gas-sensing performance of three-dimensionally ordered macroporous In2O3

Abstract

Rare earth (Tm, Er, La, Yb and Ce)-doped In₂O₃ nanostructures with three-dimensionally ordered macroporous structures (3DOM) were prepared by a colloidal crystal templating method, and their ethanol sensing properties were investigated. Rare earth doping improved the gas response and lowered the optimum operating temperature. Tm-doped 3DOM In₂O₃ had the best gas-sensing performance, and the gas sensitivity for 100 ppm ethanol was seven times higher than that of pure 3DOM In₂O₃. The reason for the different sensitivities generated by the five doping elements and the underlying mechanism of the enhanced gas response for the samples were studied.