Functionalized Nanocellulose/Multiwalled Carbon Nanotube Composites for Electrochemical Applications

Abstract

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+, IrCl6 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(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.

Application of nanocellulose composites in the environmental engineering: A review

“…Adding these nanotubes improves the composites' mechanical strength and provides it with conductivity providing the presence of that an adequate quantity of connections. As cellulose and carbon nanotubes present great connections, they are known as natural companions [111]. The composite of cellulose and carbon nanotube has gained much interest in the areas of conductive papers [112][113][114] and fibers as well as wearable electronics [115], and aerogel [116], which has been only investigated in one study.…”

Biocompatible Dispersants for Carbon Nanomaterials

“…Nanocelluloses can be functionalised to add another dimension of capabilities to this class of dispersant, as demonstrated by Durairaj et al earlier this year [43]. The study focussed on functionalising NCC and cellulose nanofibrils (CNFs)-with sulphate, carboxylate, and amino-silane moieties-to produce nanocellulose/multi-walled carbon nanotube (MWCNT) dispersions for electrochemical applications (Table 2 (4)).…”

“…The study focussed on functionalising NCC and cellulose nanofibrils (CNFs)-with sulphate, carboxylate, and amino-silane moieties-to produce nanocellulose/multi-walled carbon nanotube (MWCNT) dispersions for electrochemical applications (Table 2 (4)). The functionalisation of the nanocellulose material tailored the final product's physiochemical properties by changing its crystal structure, density, and electrochemical behaviour [43].…”

“…Functionalisation of cellulose dispersants allows for customisation of the material to suit a range of applications by modifying the dispersants physiochemical characteristics. This modifiability is particularly relevant when the dispersant will be used to produce a solid-aerogel, film, or coating-as factors such as porosity can be controlled [43]. However, it is important to note that the effects of covalent modification on celluloses structure, biocompatibility, and dispersing abilities are not well studied.…”

Role of Nanocellulose in Tailoring Electroanalytical Performance of Hybrid Nanocellulose / Multiwalled Carbon Nanotube Electrodes

“…They reported that the cellulose II based hybrid exhibited a higher sensitivity, likely due to a more macroporous structure. In our previous work, [39] we demonstrated that both CNC and CNF materials, functionalized with different surface chemistries, are capable of producing highly stable aqueous suspensions of commercial MWCNT without the need for any prior purification or chemical modification of the MWCNT and the nanocellulose / MWCNT suspensions can be used to produce highly stable and repeatable electrochemical platforms with a wide operation potential (-0.6 to +1 V), suitable for electroanalytical applications. Investigations with outer sphere redox (OSR) probes indicated that both morphological and electrostatic effects, resulting from nanocellulose geometry and functionalization, play a dominant role in the electrochemical response of the hybrid, and that these differences are further dependent on the ionic strength of the supporting electrolyte.…”