Electrocatalytic Behavior and H2O2 Detection of Carbon Nanotube/Chitosan Nanocomposites Prepared via Different Acidic Aqueous Solutions

The factors that affect the electrocatalytic activities of carbon nanotube/chitosan (CNT/CS) nanocomposite films that were cast on a glassy carbon electrode from CH3COOH, HCOOH, HCl, and citric acid aqueous solutions were investigated by cyclic voltammetry (CV). These factors include the extent of functionalization of acid-treated CNT (fCNT), the fCNT content, and the acid type used to prepare the films. The CV results revealed that the fCNT in the fCNT/CS-cast film exhibited electrocatalytic activity to redox reactions of Fe(CN)6 3-/4-used as a probe. The fCNT (having a COOH content 2.51 mmol/100 g sample) exhibited a higher electrocatalytic activity than the untreated CNT and the fCNT1 (having a COOH content 158.50 mmol/100 g sample). Among the four acids, citric acid exhibited the most uniform fCNT dispersion in the CS film, which resulted in the highest electrocatalytic activity. On the other hand, HCl resulted in a brittle fCNT/CS film and a negligible electrocatalytic activity. The fCNT/CS 2/10 film exhibited a higher electrocatalytic activity than the fCNT/CS 1/10 and 3/10 films. The amperometric analysis results revealed that when a nanocomposite film has a high electrocatalytic activity, the sensitivity for H2O2 detection in the film is also high