A theoretical study on CO sensing mechanism of In-doped SnO2 (110) surface

The CO adsorption on the In-doped SnO2 (1 1 0) surface has been studied by the first-principles calculations based on density functional theory. The study reveals that CO can be chemically adsorbed on the bridge site of the In-doped SnO2 (1 1 0) surface transforming into CO2. The favorable oxidization of CO on the surface occurs with a small reaction barrier of 1.03 eV and is exothermic by 1.72 eV. These results suggest that the In-doping can contribute to the improvement of gas sensing properties of the SnO2-based sensors for CO gas.