Preparation and electrocatalytic properties of multi-walled carbon nanotubes/chitosan composites

Functionalized multi-walled carbon nanotubes (f-MWCNTs) were prepared by mixed acids. And chitosan (CS) nanoparticles were prepared by precipitation methods. MWCNTs/CS (Mr ≥ 50 000 and Mr ≥ 100 000), MWCNTs/super high density CS, MWCNTs/CS hydrochloride and MWCNTs/carboxylation CS nanocomposites were synthesized by electrostatic self-assembly. The microstructures of MWCNTs/CS composites were analyzed by means of SEM, HRTEM and XRD. The electrochemical properties of H₂O₂ decorated with MWCNTs/CS hydrochloride composites glass-carbon electrode were tested by cyclic voltammetry. The results indicate that MWCNTs/CS hydrochloride composite possesses the best coating effects and the dispersion after standing for 12 h. The thickness of CS grafted on the surface of MWCNTs is about 3.5 nm. MWCNTs hydrochloride composite glass-carbon electrode improves the current and decreases the overpotential of H₂O₂ redox. The modified electrode displays good stability and reproducibility.