Enhanced CO2 Adsorption and Conversion Induced by Surface Oxygen Vacancy on Low-Index (010) Surface of Anatase TiO2

Abstract

Understanding the CO₂ adsorption and conversion on low-index (010) surface exposed in anatase TiO₂ is vital to improve the catalytic efficiency. Herein, different stable adsorption configurations on (010) surfaces of anatase TiO₂ are studied through density functional theory calculations. It is an interesting finding on perfect surface that the adsorption energies are weak although carbonate-like complex relates to a strong interaction between CO₂ and surfaces. Such a scenario is also established on defective (010) surfaces. Moreover, oxygen vacancy plays a greatly important role in the CO₂ adsorption and activation on anatase (010) surfaces. The introduction of oxygen vacancy not only promotes CO₂ to stably adsorb on defective surfaces with higher adsorption energies as compared to perfect ones, but also dissociates one CO bond of CO₂ for filling the vacancy and forms a CO molecule. Just as interesting is that the oxygen vacancy can also be filled by the C atom instead of the O atom when CO₂ horizontally adsorbs at the defect site. This work offers theoretical guidance to devise excellent materials for CO₂ conversion.