Hydroxylation and molecular adsorption behavior of SnO2 (110) crystal plane

Abstract

Density functional theory simulates the hydroxylation and molecular adsorption mechanism of H2O molecules on the SnO2 (110) crystal plane. The results show that the crystal plane captures H2O molecules and undergoes hydroxylation, and the crystal plane hydroxylation further chemically adsorb H2O molecules, which is confirmed by Fourier transform infrared spectroscopy. Hydroxylation promotes the adsorption of O2 molecules on the crystal plane by van der Waals forces. O2 molecules are adsorbed by van der Waals forces before and after the crystal plane hydroxylation, which resulted in the decrease and increase of the crystal plane conductivity, respectively. The results are confirmed by electrochemical impedance spectroscopy. At the same time, according to the energy optimization of the adsorption model, the change of the adsorption active site after the crystal plane hydroxylation affects the adsorption energy of the molecules on the crystal plane, which leads to the change of the crystal plane conductivity.