Functionalized Nanocellulose/Multiwalled Carbon Nanotube Composites for Electrochemical Applications

Four different types of crystalline and fibrillar nanocellulosic materials with different functional groups (sulfate, carboxylate, amino-silane) are produced and used to disperse commercial multiwalled carbon nanotubes (MWCNT). Aqueous nanocellulose/MWCNT dispersions are drop-cast on tetrahedral amorphous carbon (ta-C) substrates to obtain highly stable composite electrodes. Their electrochemical properties are studied using cyclic voltammetry (CV) measurements with Ru(NH3)(6)(2+/3+), IrCl62-/3- redox probes, in electrolytes of different ionic strengths. All studied nanocellulose/MWCNT composites show excellent stability over a wide potential range (-0.6 to +1 V) in different electrolytes. Highly anionic and more porous fibrillar nanocellulosic composites indicate strong electrostatic and physical enrichment of cationic Ru(NH3)(6)(2+/3+) in lower-ionic-strength electrolytes, while lesser anionic and denser crystalline nanocellulosic composites show no such effects. This study provides essential insights into developing tailorable nanocellulose/carbon nanomaterial hybrid platforms for different electrochemical applications, by altering the constituent nanocellulosic material properties.

Automated summary

Four types of nanocellulosic materials with different functional groups were used to disperse multiwalled carbon nanotubes, resulting in composite electrodes with excellent stability and electrochemical properties in different electrolytes. Anionic fibrillar nanocellulosic composites showed strong electrostatic and physical enrichment effects, while denser crystalline composites did not exhibit such behavior. This study provides insights for developing customizable nanocellulose/carbon nanomaterial hybrid platforms for various electrochemical applications.