title: Adsorption and oxidation of oxalic acid on anatase TiO2 (001) surface: A density functional theory study.
abstract: Anatase TiO2 (001) surfaces have attracted great interest for photo-degradation of organic species recently due to their high reactivity. In this work, adsorption properties and oxidation mechanisms of oxalic acid on the anatase TiO2 (001) surface have been theoretically investigated using the first-principles density functional theory. Various possible adsorption configurations are considered by diversifying the connectivity of carboxylic groups with the surface. It is found that the adsorption of oxalic acid on the anatase (001) surface prefer the dissociative states. A novel double-bidentate configuration has been found due to the structural match between oxalic acid and the (001) surface. More charge is transferred from the adsorbed oxalic acid to the surface with the double-bidentate configuration when comparing with other adsorption structures. Thus, there is a positive correlation relationship between the transferred charge amount and the interfacial bond numbers when oxalic acid adsorbs on the anatase TiO2 (001) surface. The adsorption energies with dispersion corrections have demonstrated that the van der Waals interactions play an important role in the adsorption, especially when adsorbates are close to the surface.
authors.affiliation: Centre for Clean Environment and Energy, Griffith School of Environment, Griffith University, Gold Coast Campus, Queensland 4222, Australia.
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.affiliation: Centre for Clean Environment and Energy, Griffith School of Environment, Griffith University, Gold Coast Campus, Queensland 4222, Australia. Electronic address: yun.wang@griffith.edu.au.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Centre for Environmental and Energy Nanomaterials, Institute of Solid State Physics, Chinese Academy of Sciences, China.
authors.forename: Haimin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Centre for Clean Environment and Energy, Griffith School of Environment, Griffith University, Gold Coast Campus, Queensland 4222, Australia.
authors.forename: Porun
authors.initials: P
authors.lastname: Liu
authors.affiliation: Centre for Clean Environment and Energy, Griffith School of Environment, Griffith University, Gold Coast Campus, Queensland 4222, Australia; Centre for Environmental and Energy Nanomaterials, Institute of Solid State Physics, Chinese Academy of Sciences, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Zhao
keywords: Adsorption; Anatase (001) surface; Density functional theory; Oxalic acid; Van der Waals interactions