Au doped In2O3 nanoparticles: Preparation, and their ethanol detection with high performance

Precious metals doping can greatly change the gas sensing performance of semiconductor metal oxide . Herein, the Au-doped In 2 O 3 nanoparticles (NPs) were prepared via a combination solvothermal and liquid-phase reduction method, and the obtained nanoparticles were characterized by various techniques. The results indicated that Au nanocrystals with a diameter ca. 5 nm were uniformly distributed on the surface of the irregular In 2 O 3 NPs. Importantly, compared with undoped In 2 O 3 , the specific surface area of all the Au-doped In 2 O 3 NPs increased. And all the Au-doped In 2 O 3 sensors greatly improved the gas sensing performance towards ethanol. The optimal operating temperature reduced from 240 °C for undoped In 2 O 3 to 200 °C for Au-doped In 2 O 3 . Of them, the 4 wt% Au-doped In 2 O 3 sensor displayed highly response (106 towards ethanol at 100 ppm) at the optimal operating temperature, good linear coefficient, high reproducibility, and long-term stability towards ethanol. Moreover, through the detection of seven gases including ethanol, such as methanol, acetone , benzene, formaldehyde, isopropanol, and nitrogen dioxide， we found that the fabricated sensor based on 4 wt% Au-doped In 2 O 3 had good selectivity towards ethanol. Finally, the mechanism of the excellent performance of the 4 wt% Au-doped In 2 O 3 sensor for ethanol was explained.