Functionalized Nanocellulose/Multiwalled Carbon Nanotube Composites for Electrochemical Applications
Vasuki Durairaj, Panpan Li, Touko Liljeström, Niklas Wester, Jarkko Etula, Ilona Leppänen, Yanling Ge, Katri S. Kontturi, Tekla Tammelin, Tomi Laurila, Jari Koskinen
Abstract
High Resolution Image Download MS PowerPoint Slide 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(NH 3 ) 6 2+/3+, IrCl 6 2–/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(NH 3 ) 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.