Cd掺杂In_2O_3多孔纳米球的制备及其甲醛气敏性能

Fabrication and formaldehyde gas sensing property of porous Cd-doped In_2O_3 nanospheres

采用水热和煅烧工艺制备具有良好分散性的多孔纳米球形Cd掺杂In_2O_3颗粒,并对其甲醛气敏性能进行测试。结果表明:Cd掺杂量较低时得到的粉末为纯立方In_2O_3相,当Cd掺杂量高于4.1%(原子分数)时,除存在立方In_2O_3相外,还存在微量立方Cd O相。Cd掺杂可极大提高In_2O_3多孔纳米球的甲醛气敏性能并且降低其最佳工作温度,4.1%Cd-In_2O_3最佳工作温度为60℃,远低于纯In_2O_3的最佳工作温度120℃,能显著降低In_2O_3传感器的能耗。且4.1%Cd-In_2O_3在60℃下对50×10^(-6)甲醛的灵敏度高达1 074,远高于纯In_2O_3在120℃下的最高灵敏度57。4.1%Cd-In_2O_3在60℃对50×10^(-6)甲醛的响应和恢复时间分别为326 s和912 s;Cd掺杂In_2O_3还可明显提高其气敏选择性能。

Spherical Cd-doped In2O3 nanoparticles with uniform dispersity and porous structure were prepared by hydrothermal and calcination processes. The formaldehyde gas sensing property of porous Cd-doped In2O3 nanospheres was tested. The results show that cubic In2O3 phase is formed with the low Cd doping concentration, and mixed In2O3 and CdO phases are obtained when the Cd doping atomic fraction is higher than 4.1%. Compared to pure In2O3 materials, Cd-doped In2O3 can improve the performances in detecting HCHO, and decreases optimum temperature of the In2O3 sensor as well. The optimum operating temperature of 4.1%Cd-In2O3 is 60℃, which is much lower than that of the pure In2O3 （120℃）. Pure In2O3 has the maximum sensitivity to 50×10^-6 HCHO （S=57） at 120℃. While 4.1%Cd-doped In203 materials have maximum sensitivity to 50×10^-6 HCHO （S=1074） at 120℃, and the response and recovery times of 4.1%Cd-doped In2O3 particles are about 326 s and 912 s, respectively. Selectivity properties of the In2O3 sensor can also be improved by the doping of Cd.