Evaluation of Alkyl‐Ferrocene Monolayers on Carbons for Charge Storage Applications, a Voltammetry and Impedance Spectroscopy Investigation

Abstract

Electrochemical properties of functionalized carbons with ferrocene-alkyl monolayer were evaluated with different electrolytes and solvents for charge storage applications. Investigations were performed both by cyclic voltammetry and impedance spectroscopy using edge plane pyrolytic graphite (PG) electrodes, being a good example of fragile and porous carbon material. The functionalization method is based on the electrografting of protected aryldiazonium ions that leads after deprotection to the formation of a covalently attached mono-layer. In a second step, C 11 -long chain alkyl ferrocene is attached on the platform. The functionalization considerably increases the charge density by a factor of 5-10 depending on the electrolyte with the advantage that it does not alter the structure of the carbon surface. The grafted layer presents a very fast electron transfer kinetics providing an easy way for increasing the charge density in devices like supercapacitors, the charging time being limited by the resistance of the electrolyte.

Nanofabrication Techniques in Large-Area Molecular Electronic Devices

“…Likewise, materials, such as carbon nanodots (CD) have been immobilized onto carbon substrates, through the attachment of nitrogen moieties at the nanodot surface (diazotized N-CD), resulting in carbon substrates with new performances in sensing applications [330]. Finally, other conductive substrates such as carbon composite electrodes, including thermoplastic electrodes (TPE) [331], edge plane pyrolytic graphite electrodes (PGEs) [332], glassy carbon (GC), and pyrolyzed photoresist (PPF) [333], have also been modified by electrografting.…”

Composites and Copolymers Containing Redox-Active Molecules and Intrinsically Conducting Polymers as Active Masses for Supercapacitor Electrodes—An Introduction

“…2,2-bis(ethylferrocenyl)propane intercalated into GO and subsequently combined with PANI yielded an electrode material with 89.13% capacitance retention after 3000 cycles [100]. A monolayer of (11azidoundecyl)ferrocene ( Figure 16) on carbon has been examined with respect to electron transfer kinetics and possible application in a supercapacitor [101]. 4-Azidobutylferrocene (the singly substituted version of the compound shown in Figure 15) has been attached to rGO, with PANI a compound was prepared for use as a supercapacitor electrode material showing 89% capacitance retention after 2000 cycles [98].…”

“…2,2-bis(ethylferrocenyl)propane intercalated into GO and subsequently combined with PANI yielded an electrode material with 89.13% capacitance retention after 3000 cycles [ 100 ]. A monolayer of (11-azidoundecyl)ferrocene ( Figure 16 ) on carbon has been examined with respect to electron transfer kinetics and possible application in a supercapacitor [ 101 ].…”

Role of the Supporting Electrolyte Ions and Additives on the Electron Transport Properties of Electrografted Films Bearing Ferrocenyl Moieties

“…Due to the redox catalysis properties of ferrocene, modification of electrode surface with it has been of great interest in the field of sensor and biosensors [20–25] . In addition to energy storage applications, [26–30] the presence of ferrocene on modified electrodes has also been relevant to investigate the properties of grafted films [31,32] . Ferrocene compounds have been deposited on the surface of different conductor materials, however, the use of carbon materials as electrode substrate is of relevance due to their physicochemical properties and wide variety of allotropic forms [33,34] .…”