jp212537q_si_001.pdf (243.54 kB)
3D-Addressable Redox: Modifying Porous Carbon Electrodes with Ferrocenated 2 nm Gold Nanoparticles
journal contribution
posted on 2012-04-26, 00:00 authored by Kwok-Fan Chow, Rajesh Sardar, Megan B. Sassin, Jean Marie Wallace, Stephen W. Feldberg, Debra R. Rolison, Jeffrey W. Long, Royce W. MurrayNanostructured, high-surface-area carbon electrodes have
large
electrochemical double-layer capacitances compared to smooth-surfaced
electrodes because of their enhanced internal surface areas, e.g.,
several hundred m2g–1. In the present
work, we demonstrate that the electrical capacitance of carbon “nanofoams”,
both in commercially available forms and as prepared by the authors,
can be significantly enhanced by the insertion into their pores of
small Au nanoparticles (∼2 nm diameter core) to whose surfaces
are bonded ferrocenyl-hexane thiolate ligands (SC6Fc) (>40 per
nanoparticle).
The enhanced capacitive behavior of the modified nanoporous carbon
(in CH3CN or CH2Cl2 with 1.0 or 2.0
M Bu4NPF6 as the supporting electrolyte) is
clearly seen in their cyclic voltammetric responses and is attributed
to a combination of the ferrocene redox-capacity and the double-layer
capacity of the intercalated nanoparticles. Footprint-normalized,
volume-normalized, and gravimetric-normalized integral capacitances
of 0.28 F cm–2, 39 F cm–3, and
66 F g–1 are realized over a 1 V potential range.
We suggest this approach as a conceptual pathway to improve the science
of electrochemically based energy storage systems (e.g., “supercapacitors”).