Adsorption and sensing performance of air pollutants on a β-TeO 2 monolayer: a first-principles study.

Two-dimensional (2D) β-TeO 2 is a novel semiconductor with potential applications in electronic circuits due to its air-stability and ultra-high carrier mobility. In this study, we explore the possibility of using a 2D β-TeO 2 monolayer for the detection of gaseous pollutants including SO 2 , NO 2 , H 2 S, CO 2 , CO, and NH 3 gas molecules based on first-principles calculations. The adsorption properties including the adsorption energy, adsorption distance and charge transfer indicate that the interaction between 2D β-TeO 2 and the six gases is via a physisorption mechanism. Among the six gas adsorption systems, the SO 2 adsorption system has the most negative adsorption energy and the largest charge transfer. In addition, the adsorption of SO 2 obviously changes the electrical conductivity of the β-TeO 2 monolayer because the band gap decreases from 2.727 eV to 1.897 eV after adsorbing SO 2 . Our results suggest that the 2D β-TeO 2 should be an eminently promising SO 2 sensing material.