High-Throughput Experimental Technology: Rapid Identification of the Precious Metal Modified In2O3 for NO2 Low-Temperature Sensing

It often takes much time to obtain the components of high-performance metal oxide semiconductor gas-sensitive materials by inefficient “trial and error method.” In this study, high-throughput experimental technology (HTET) was used to modify the surface of Indium trioxide (In2O3) nanoparticles, and the In2O3 precious metal gas-sensitive sensors with different surface modification rates were prepared. The gas-sensitive properties of the sensors were systematically studied. HTET can accelerate the synthesis of materials and the screening of gas-sensitive properties, and it significantly improves experimental efficiency. The results show that the 0.5 mol% silver modified In2O3 (Ag
$_{{0.5}}$
In) sensor leads to an ultrahigh response (
${R}_{\text {gas}}/{R}_{\text {air}} =923.6$
) to 5 ppm NO2 at 50 °C 5.75 times of the pure In2O3 sensor. In addition, the sensor exhibits fast response (61.3 s) and recovery (106.3 s) times, high selectivity, and stable repeatability. The enhancement of the excellent NO2 gas sensitivity is reached mainly due to synergistic effect of the catalysis of the precious metals and the increase of surface chemisorption oxygen.