First-principles study of CO2 adsorption on KNTN (001) surfaces

• Published in: Applied surface science Vol. 308; pp. 269 - 274
• Main Authors: Shen, Yanqing, Wang, Wenhan, Wang, Xiaoou, Zhou, Zhongxiang, Fei, Weidong
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.07.2014; Elsevier
• Subjects: Band gap; CO2 adsorption; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; First principles; KNTN; Perovskites; Physics; First principles; Perovskites; Band gap; CO2 adsorption; KNTN; Energy gap; adsorption; Inorganic compounds; CO; Carbon oxides
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2014.04.151

•Density functional theory study of CO2 adsorption on K1−yNayTa1−xNbxO3 surface terminations.•CO2 molecule prefers to adsorb at the NaO bridge site on the K(Na)O-termination and O top site on the Ta(Nb)O2-termination.•The interaction mechanism between CO2 and KNTN surface is discussed.•The KNTN surface prefers to adsorb CO2 rather than water molecule.•The charge rearrangements caused by the CO2 adsorption results in a band gap increase of KNTN surface. The adsorption of CO2 on K1−yNayTa1−xNbxO3 (KNTN) surface terminations has been studied using density functional theory. The preferred adsorption sites are found to be the NaO bridge site on the K(Na)O-termination and O top site on the Ta(Nb)O2-termination. In the most favorable configurations, the CO2 molecule is bent and the CO bonds are elongated, indicating the CO2 activation. After adsorption, the band gap of the surface is enlarged, relevant to the electrons density redistribution. The results illustrate that the electronic structure of KNTN surface is sensitive with CO2 adsorption. The results provide fundamental insight into the CO2 adsorption mechanism on KNTN surface and potential application on gas sensing.