Electrochemical functionalization of single wall carbon nanotubes with phosphorus and nitrogen species

Abstract

Single Wall Carbon Nanotubes (SWCNTs) have been successfully functionalized by electrochemical oxidation in presence of 4-aminophenyl phosphonic acid (4-APPA).Electrochemical modification has been performed by cyclic voltammetry using different upper potential limits, producing the incorporation of N and P functionalities on SWCNT through polymerization reactions, although some covalent attachment cannot be discarded. Electrochemical oxidation in presence of CNT produces polymerization of 4-APPA, what has been related to the interaction between monomer and the CNT surface.The voltammograms of the functionalized SWCNT show different well-defined redox processes that are maintained at high pH. Raman spectroscopy shows that the structure of the SWCNT is maintained even at high potentials suggesting that oxidation selectively occurs in the 4-APPA monomer favoring polymer chain growth. The degree of modification of SWCNT can be easily controlled by selecting the electrochemical conditions.

Pyrroloquinoline quinone-dependent glucose dehydrogenase bioelectrodes based on one-step electrochemical entrapment over single-wall carbon nanotubes

“…This voltammetric behavior is similar to that observed in absence of GDH in the solution (see Fig. S2) and it has been previously observed in precious works developed in acid media [41]. The observed processes were associated to the functionalization of SWCNTs with the species produced during oxidation of 4-APPA.…”

Tailoring Intrinsic Properties of Polyaniline by Functionalization with Phosphonic Groups

“…A slight increase in phosphate or phosphoric groups can be observed when a higher P-loading is reached (from 19% in PANI2APPA 80/20 to 30% in PANI2APPA 50/50). This effect can be explained by oxidation of part of the phosphonic groups to phosphoric groups, as it has been also observed in previous studies for phosphonic acid ring-substituted polyanilines synthesized via an electrochemical route when high oxidation potentials are applied [39,46]. No residual phosphorus was detected in the PANI.…”

Fabrication, Functionalization, and Application of Carbon Nanotube-Reinforced Polymer Composite: An Overview

“…Several methods of functionalization are chemical [ 42 ], electrochemical [ 43 ], mechano-chemical [ 44 ], and plasma [ 45 ] in nature. The functionalization of CNTs is used to functionalize their surfaces and side chains.…”