Molecular adsorption behavior and photoelectric properties of SnO2 (221) crystal plane

Abstract

In this paper, the molecular adsorption behavior of the SnO2 (221) crystal plane is simulated by density functional theory, and the photoelectric properties of the crystal plane are studied. Through theoretical simulation, H2O, O2, and N2 molecules are located on three different adsorption active sites of the crystal plane. The individual adsorption of the three molecules reduces the conductivity of the crystal plane. The conductivity increases when the molecules are co-adsorbed. The characteristic adsorption species (CAS) of the crystal plane are H2O and O2 molecules. This is consistent with the experimental results of electrochemical impedance spectroscopy (EIS). The O2 molecule shifts the response peak of the photocurrent spectrum to a low wavelength. Understanding the CAS of the crystal plane and its influence on the optical and electrical properties of materials has enlightening significance for further analysis of the photoelectric behavior of materials, and is helpful to provide the theoretical and experimental basis for the controllable design and synthesis of gas-sensitive materials.