CaSiO3 (001) surface reconstruction and CO2 molecular adsorption

The study on CO2 adsorption on CaSiO3 surface has scientific and economic necessity and is of much interest for exploring carbonization mechanism. Here, the CaSiO3 (001) surfaces with CaO-termination and SiO-termination were studied. The observed surface structure, charge distribution and the density of states demonstrate that the chemical and physical properties of CaSiO3 (001) surfaces are different from bulk. The detailed analysis on the structural geometries, energy and electronic properties for the process of carbon dioxide adsorption on the two surfaces in various models demonstrates when the carbon and oxygen atoms of carbon oxide molecular react with surface oxygen and calcium atoms at the same time, the bent modes of CO2 are most energetically stable and produce carbonate. It is presented that the adsorption efficiency is considered higher on CaO-terminated surface than on SiO-terminated surface with the same surface area, therefore future experiment work should focus on modification of the wollastonite surface to improve proportion of the CaO-terminated surface. CO2 molecular reacts with surface oxygen and calcium atoms to produce carbonate. [Display omitted] •Studying CO2 adsorption on CaSiO3 has scientific and economic necessity.•Polar surface reconstruction and charge distribution is responsible for CO2 adsorption.•The bent modes of CO2 are most energetically stable and produce carbonate.•The CaO-terminated surface has higher adsorption efficiency.