Adsorption-desorption of F2 diatomic molecule on Ti (100) surface at different coverages

  • D M Tshwane Council for Scientific and Industrial Research
  • R Modiba Council for Scientific and Industrial Research
  • G Govender Council for Scientific and Industrial Research
  • P E Ngoepe University of Limpopo
  • H R Chauke University of Limpopo
Keywords: Fluorine ion, desorption energy, Ti surface, density functional theory

Abstract

Fluorine molecules and ions are used as an etchant for metal surface processing. The presence of fluorine significantly influences the electrochemical behaviour on a metal surface, which has major relevance for etching, corrosion, electro-catalysis and galvanic deposition processes. Although the fluorine ions play an important role in metal surface etching, the studies remain limited and unclear, especially at the atomistic scale. In this work, density functional theory is used to investigate the structural and electronic properties of F2 diatomic molecule adsorption on Ti (100) surface at different coverages. Results revealed a dissociative adsorption mechanism of F2 on the Ti (100) surface. Adsorption energy analysis of F2 on Ti (100) surface denotes an exothermic process. Moreover, increasing F2 coverage resulted in the formation of TiF4 and Ti2F6 molecules on the surface. In addition, the calculated heat of formation for TiF4 was found to be more favourable than Ti2F6 species. Calculated desorption energies for TiF4 and Ti2F6 is 11.73 eV/atom and 9.04 eV/atom, suggesting non-spontaneous.

Author Biographies

D M Tshwane, Council for Scientific and Industrial Research

Advanced Materials Engineering, Materials Science and Manufacturing, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, and Materials Modelling Centre, University of Limpopo, Private Bag X1106, Sovenga, 0727, South Africa

R Modiba, Council for Scientific and Industrial Research

Advanced Materials Engineering, Materials Science and Manufacturing, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, South Africa

G Govender, Council for Scientific and Industrial Research

Advanced Materials Engineering, Materials Science and Manufacturing, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, South Africa

P E Ngoepe, University of Limpopo

Materials Modelling Centre, University of Limpopo, Private Bag X1106, Sovenga, 0727, South Africa

H R Chauke, University of Limpopo

Materials Modelling Centre, University of Limpopo, Private Bag X1106, Sovenga, 0727, South Africa

Published
2022-01-25
How to Cite
Tshwane, D., Modiba, R., Govender, G., Ngoepe, P., & Chauke, H. (2022). Adsorption-desorption of F2 diatomic molecule on Ti (100) surface at different coverages. Suid-Afrikaans Tydskrif Vir Natuurwetenskap En Tegnologie / <i>South African Journal of Science and Technology</I&gt;, 40(1), 200-204. Retrieved from http://satnt.co.za/index.php/satnt/article/view/904
Section
Conference of the South African Advanced Materials Initiative

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