UNDERSTANDING THE IMPACT OF METAL DOPING (Co, Ni, Cu) ON THE STRUCTURAL AND ELECTRONIC PROPERTIES OF SINGLE-WALLED CARBON NANOTUBES: THEORETICAL INSIGHTS

The broadly parametrized self-consistent tight-binding quantum chemical method – GFN2-xTB was employed to investigate the impact of Co, Ni, and Cu metal doping on the structural and electronic properties of single-walled carbon nanotube (CNT). Computational results for interaction energy, bond order, and Mulliken atomic charge indicated that the doped metals form chemical bonds with the CNT surface through metal-carbon bond formation. Significant charge transfer from the metal atoms to the CNT was observed, most notably in the case of Cu/CNT. Analysis of ionization energy (IP), electron affinity (EA), and global electrophilicity index (GEI) values revealed that the presence of metals increases IP, EA, and GEI values compared to the pristine CNT. The Lewis acidity of the studied systems increases in the order of Ni/CNT < Co/CNT < Cu/CNT. Calculations of the fractional occupation number weighted density (FOD) indicated that in the metal-doped CNT systems, the density of hot and chemically active electrons is predominantly concentrated on the metal atoms. Molecular orbital analyses demonstrated the contribution of metal atoms to the HOMO and LUMO of the system. Additionally, the centroid distance (Dij) between the HOMO and LUMO of the M/CNT (M = Co, Ni, Cu) is influenced by metal doping. Among the studied systems, Co/CNT exhibits the lowest energy gap between the LUMO and HOMO and the highest Dij value, suggesting its suitability for photocatalytic applications. For citation: Pham Thi Be, Phan Tu Quy, Bui Cong Trinh, Nguyen Thi Kim Giang, Nguyen Thi Thu Ha Understanding the impact of metal doping (Co, Ni, Cu) on the structural and electronic properties of single-walled carbon nanotubes: theoretical insights. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 73-79. DOI: 10.6060/ivkkt.20246712.7115.