研究光学气敏材料吸附气体后的光学气敏特性是气敏传感研究的热点问题。研究了金红石相TiO2(110)面吸附NH3的微观机制和光学气敏特性。结果表明,NH3分子容易被含氧空位缺陷的金红石相TiO2(110)面所吸附,且提高表面氧空位的比例,有利于NH3稳定吸附。表面吸附NH3分子以负电荷中心向下为主,当氧空位比例为33%时,吸附能为1.7313eV。表面吸附NH3为化学吸附,NH3的H原子被还原而N原子被氧化。含氧空位的表面吸附NH3在可见光1.5~3.1eV范围内,表面氧空位比例越大,其对可见光吸收和反射能力越强,光学气敏性越灵敏。 It is a hot issue in gas sensing research to study the optical gas-sensing properties of optical gas-sensitive materials. The microscopic mechanism and optical gas sensing properties of adsorbing NH3 on rutile TiO2 (110) surface were studied. The results show that NH3 molecules are easily adsorbed on the (110) surface of rutile TiO2 with oxygen vacancies and the ratio of surface oxygen vacancies is increased, which is in favor of the stable adsorption of NH3. The surface adsorbed NH3 molecules are mainly negatively charged center down, when the oxygen vacancy ratio is 33%, the adsorption energy is 1.7313eV. Surface adsorption of NH3 for chemical adsorption, NH3 H atoms are reduced and N atoms are oxidized. Surface adsorption of oxygen vacancies NH3 in the visible light 1.5 ~ 3.1eV range, the greater the proportion of surface oxygen vacancies, the greater its ability to absorb and reflect visible light, the more sensitive optical gas sensitivity.