Sensing mechanism of anatase TiO₂(101) surface adsorption of CO₂ molecules

Exploration and application of the gas sensitive sensor material of metal oxide optics is a hot issue. The adsorption energy, adsorption distance, density of states and optical properties were studied from the plane wave ultra-soft pseudo-potential technology based on the density function theory(DFT). The results through simulation calculation of CO2 adsorbed on the anatase TiO2(101) surface show that only containing oxygen vacancy surface can stably adsorb CO2 molecules; the higher of oxygen vacancy concentration, the more obvious adsorption effect. The adsorption energy is positive value when CO2 molecules horizontal adsorption on surface, the best adsorption model is CO2 molecules horizontal O-terminal dsorption on surface with two oxygen vacancies. Compared with the density of states, a new peak appears nearby the fermi level because of surface with oxygen vacancies and 2p electrons of CO2 molecules doping in surface. The transition probability, optical gas sensitive features, absorption coefficient and reflectivity can be improved in the low-energy scope of visible light.