First-principles insights into hydrogen trapping in interstitial-vacancy complexes in vanadium carbide. Issue 34 (19th August 2022)

• Record Type: Journal Article
• Authors: Tang, Shuai; Li, Lin-xian; Peng, Qing; Yan, Hai-le; Cai, Ming-hui; Li, Jian-ping; Liu, Zhen-yu; Wang, Guo-dong
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 34(2022)
• Page Start: 20400
• Page End: 20408
• Publication Date: 2022-08-19
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp02425j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Hydrogen trapping is a key factor in designing advanced vanadium alloys and steels, where the influence of carbon vacancies is still elusive. Abstract : Hydrogen trapping is a key factor in designing advanced vanadium alloys and steels, where the influence of carbon vacancies is still elusive. Herein we have investigated the effect of carbon vacancies on the hydrogen trapping of defect-complexes in vanadium carbide using first-principles calculations. When a carbon vacancy is present, the second nearest neighboring trigonal interstitial is a stable hydrogen trapping site. A C vacancy enhances the hydrogen trapping ability by reducing the chemical and mechanical effects on H atom solution energy. Electronic structure analysis shows that C vacancies increase the charge density and the Bader atomic volume, leading to a lower H atom solution energy. The strength of the V–H bond is predominant in determining the hydrogen trapping ability in the presence of a C vacancy, in contrast to that of a C–H bond when the C vacancy is absent.