Indexed by:期刊论文

Date of Publication:2018-04-15

Journal:COMPUTATIONAL MATERIALS SCIENCE

Included Journals:SCIE、EI

Volume:146

Page Number:1-8

ISSN No.:0927-0256

Key Words:Oxygen defect; alpha-Fe2O3 (001) surface; NO molecule; Adsorption; Gas-sensing

Abstract:Using density functional theory (DFT), we investigated and discussed the adsorption characteristics, gas-sensing response and gas-sensing mechanism of NO molecule on alpha-Fe2O3 (0 0 1) surface with and without oxygen defect (V-O). The pure and oxygen-defective alpha-Fe2O3 (0 0 1) surface exhibited opposite electron transfer. The theoretical results proved that the NO molecule acted as a donor for pure alpha-Fe2O3 (0 0 1) surface. However, it failed to explain the increasing resistance of n-type metal oxide materials. For oxygen-defective alpha-Fe2O3 (0 0 1) surface, NO molecule acted as an acceptor. The results leaded to a decreasing electron-carrier concentration, and then resulted in an increasing resistance of oxygen-defective alpha-Fe2O3 (0 0 1) surface after NO molecule was introduced into. The direction of electron transfer was reversed by oxygen defect. In addition, the V-O-NO adsorption configuration induced more stable adsorption structure and more significant electron transfer effects between NO molecule and oxygendefective alpha-Fe2O3 (0 0 1) surface. The V-O-NO adsorption configuration would have better gas-sensing performance for alpha-Fe2O3 (0 0 1) surface. (C) 2018 Elsevier B.V. All rights reserved.