First principles investigation on selective hydrogen sensing properties of α-phase TeO2

alpha-phase TeO2 is a promising sensing material because of its unique ability to detect hydrogen gas. To investigate atomic-level mechanism on gas sensing of TeO2, the interaction between H-2, NH3, SO2, CO2, H2S, CH4 gases and TeO2 are studied via first principles simulations. By the calculated adsorption energy, radial distribution function, band gap and charge transfer, TeO2 shows a superior selective detection performance to hydrogen and it is consistent with experimental conclusion. The H-H bond of H-2 break after adsorption and a new H-O bond with length of 0.98 A forms between TeO2 and H-2. Moreover, the adsorption of H-2 causes an obvious increasing of DOS near the Fermi level, indicating a clear change in the electric conductivity. The calculated self-diffusion co-efficients show that the diffusion of hydrogen molecule in TeO2 is much easier than the other gases, suggesting a fast response of H-2 by TeO2. This work provides a theoretical foundation for analysis and design of TeO2-based hydrogen sensor. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Alpha-phase TeO2 is a promising sensing material for detecting hydrogen gas, showing superior selective detection performance and fast response to hydrogen. The interaction between various gases and TeO2 at the atomic level was studied via first principles simulations, providing a theoretical foundation for the design of TeO2-based hydrogen sensors.