The interaction between HCHO and TiO2 (1 0 1) surface without and with water and oxygen molecules
Abstract
The interactions between formaldehyde (HCHO) molecule and TiO2 (1 0 1) surface without and with water and oxygen were studied using density functional theory calculations. The adsorption energy of HCHO adsorption on TiO2 surface without water and oxygen is -360.96 kJ/mol, and HCHO molecule is not dissociated. The oxygen and carbon atoms of HCHO are bonded to the titanium and oxygen (O1) atoms of TiO2 surface, respectively, and form a dioxymethylene (CH2O2) structure. The adsorption energy of HCHO adsorption on TiO2 surface system with water and oxygen is -723.40 kJ/mol, and O2, H2O and HCHO molecules are all dissociated. HCHO molecule not only interacts with TiO2 surface, but also combines with O2 molecule. Two Csbnd H bonds of HCHO are broken, one hydrogen atom (H1) is bonded to the oxygen atom (O2) of O2, while another hydrogen atom (H2) is bonded to the O atom (O1) of TiO2 surface. The remaining Csbnd O bond that the dissociated and new formed Hsbnd O bonds can be oxidized to form carbon dioxide and water in subsequent action by oxygen from the atmosphere. H2O and O2 molecules have a great effect on the degradation process of HCHO molecule on TiO2 (1 0 1) surface.
- Publication:
-
Applied Surface Science
- Pub Date:
- October 2018
- DOI:
- 10.1016/j.apsusc.2018.05.206
- Bibcode:
- 2018ApSS..455..410W
- Keywords:
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- Anatase TiO<SUB>2</SUB> (1 0 1) surface;
- Water and oxygen;
- DFTB;
- Formaldehyde adsorption;
- Interaction