Rare earth element-doped porous In2O3 nanosheets for enhanced gas-sensing performance

Rare earth (La, Pr, Sm, Ce and Yb)-doped porous In2O3 nanosheets are prepared by a solvothermal method. The effect of rare earth elements on the structure, morphologies and gas-sensing performance of In2O3 nanosheets is systematically investigated. The mixed phase composed of c-In2O3 and rh-In2O3 can be transformed into rh-In2O3 by doping with rare earth elements. After doping with rare earth elements, the morphology can be changed from compact nanosheets to porous sheets. Compared with pure In2O3 and La, Pr, Sm, Ce-doped porous In2O3 nanosheets, Yb-doped In2O3 nanosheets present the best gas-sensing performance. Among 3%-10% Yb-doped samples, 6% Yb-doped In2O3 porous nanosheets exhibit the optimal gas-sensing performance to 5 x 10(-6)-750 x 10(-6) acetone, giving a high response of 15.3 toward 50 x 10(-6) acetone and fast response/recovery time at the operating temperature of 220 degrees C. Moreover, 6% Yb-doped porous In2O3 nanosheet sensor also exhibits excellent selectivity and stability, indicating its potential in the next-generation gas sensor. Graphic abstract