Abstract
This work reports new results concerning the electrochemical functionalization of multi-wall carbon nanotubes (MWCNT) and carboxyl-functionalized multi-wall carbon nanotubes (MWCNT-COOH) with polydiphenylamine (PDPA) obtained by the in-situ electrochemical polymerization of diphenylamine (DPA). A key process of this study is the photochemical interaction under UV light, which takes place between diphenylamine (DPA) and carbon nanostructures of the type MWCNT and MWCNT-COOH, respectively, as highlighted by UV–VIS spectroscopy and photoluminescence (PL). These photochemical processes can significantly affect the polymerization pathway, demonstrating that the electrochemical functionalization of MWCNT/MWCNT-COOH with PDPA must be carried out under dark conditions. The influence of monomer and electrolyte concentration on the electrochemical functionalization process of MWCNT/MWCNT-COOH with PDPA is shown in detail. The characteristics of the PDPA-functionalized carbon nanotubes are confirmed by Raman scattering and FTIR spectroscopy, providing a comprehensive understanding of the electrochemical functionalization mechanism.