Structural and electronic properties of single-walled carbon nanotubes adsorbed with 1-pyrenebutanoic acid, succinimidyl ester

The adsorption of a 1-pyrenebutanoic acid, succinimidyl ester (PSE) interacting with metallic armchair (n, n) carbon nanotubes (CNTs) (n= 3–13) was investigated by using a density-functional tight-binding method with an empirical van der Waals force correction. In this study of large systems involving weak interactions, our calculations showed that the pyrene ring of PSE could be spontaneously absorbed onto the CNTs surface through π-π stacking at the physisorption distances. Increasing of the CNTs diameter leads to a higher adsorption energy. After adsorption of PSE on its sidewall, the geometric and electronic structures of CNTs are basically undamaged. CNTs contribute to the main peak of the electron excitation procedure in the UV/vis spectrum, with a slight red shift after adsorption of PSE. Supported by the Research Grants Council of Hong Kong SAR (Project No. CityU 103907), the National Basic Research Program of China (Grant No. 2006CB933000) and Centre for Applied Computing and Interactive Media (ACIM)