Simple dispersion of carbon nanofibers in a naturally occurring polyphenol in water and their electrochemical characteristics

Carbon nanofibers are hydrophobic with poor dispersion in water. They are normally functionalised using highly acidic solutions and elevated temperatures. In this communication, we show that tannic acid can be employed at room temperature using a simple sonication method to give very good dispersions of the CNFs in distilled water. Using a factorial design, the three components, the sonication period, the concentration of tannic acid and the concentration of CNFs were found to be significant, while the concentration of the tannic acid as a single component had an equally significant effect. The optimum conditions were 1.0–1.25 mg mL−1 of CNFs, and 0.85 to 1.0 mM of tannic acid with a sonication period between 50 and 60 min. The well-dispersed CNFs exhibited very good electrochemical characteristics, with efficient electron transfer in the oxidation of acetaminophen, which was used as a model analyte.