A biopolymer gel-decorated cobalt molybdate nanowafer: Effective graft polymer cross-linked with an organic acid for better energy storage

Ramkumar, R. and Minakshi, M.ORCID: 0000-0001-6558-8317 (2016) A biopolymer gel-decorated cobalt molybdate nanowafer: Effective graft polymer cross-linked with an organic acid for better energy storage. New Journal of Chemistry, 40 (3). pp. 2863-2877.

Abstract

Nanoflake-like α-CoMoO4 was prepared with the aid of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), as an electrode material for supercapacitors by scalable solution combustion synthesis (SCS). The specific capacitance of the fabricated hybrid device (CoMoO4/CTAB vs. activated carbon (AC)) was 39 F g-1, a marginal increase compared to that of the as-prepared (parent) CoMoO4 (24 F g-1). To achieve better energy storage, modification was carried out on CoMoO4 by grafting chitosan onto it in the presence of a weak acetic acid (AA) or citric acid (CA) crosslinking agent. The biopolymer chitosan is cross-linked when using CA as a cross-linker, while in the case of acetic acid, grafting of chitosan/AA does not occur. The improved properties of CTAB- and polymer-modified CoMoO4 were evaluated using physical and electrochemical methods and compared with the as-prepared (parent) compound. The polymer-modified composite exhibited a maximum specific capacitance of 71 F g-1 at 2 mA cm-2 with a capacity retention of 81% after 2000 cycles, about twofold higher than that of the CTAB-modified electrode. The influence of surfactant and chitosan concentrations on the specific capacitance is also established. A solid state capacitor was fabricated using CoMoO4vs. AC, with chitosan as the gel separator. High resolution transmission electron microscopy (HR-TEM) and field emission scanning electron microscopy (FE-SEM) images support the cross-linking strategy and nanowafer-like morphology with a honeycomb arrangement.

Item Type:	Journal Article
Murdoch Affiliation(s):	School of Engineering and Information Technology
Publisher:	Royal Society of Chemistry
Copyright:	© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/30424

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