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论文类型：期刊论文

发表时间：2018-04-15

发表刊物：COMPUTATIONAL MATERIALS SCIENCE

收录刊物：SCIE、EI

卷号：146

页面范围：1-8

ISSN号：0927-0256

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

摘要：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.