Electrochemical and spectroscopic characterization of quinone functionalized exfoliated graphite

Abstract

Natural graphite was exfoliated by thermal decomposition of graphite-bisulfate intercalation compound. Oxidative/reductive pre-treatment of exfoliated graphite was subsequently carried out to introduce various functional groups on the graphite surface. The resulting material was covalently modified with redox active quinones. The covalent modification was effected through oxygen containing functional groups formed on the graphite surface. The modified exfoliated graphite was characterized by infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS). Electrochemical characterization of the pressed pellets of the modified graphite showed that the modification occurred at the edge sites. These electrodes were found to be very stable and the surface renewal was simply accomplished by polishing the surface using SiC emery sheets. Application of the benzoquinone modified electrode for the electrocatalysis of ascorbic acid oxidation was demonstrated.

Transfer Printing of Metallic Microstructures on Adhesion‐Promoting Hydrogel Substrates

“…[ 57,58 ] P(HEMA-co -DMA) hydrogels with a 10:1.23 ratio of HEMA to DMA exhibit a storage modulus G′ HEMA -co -DMA = 8.2 ± 1.2 kPa ( ω = 0.1 rad s −1 ), which is comparable to the storage modulus of P(HEMA) at the same frequency G′ HEMA = 7.7 ± 0.7 kPa (Figure 1 c). Both G′ HEMA -co-DMA and G′ HEMA are largely frequency independent.…”

Recent Updates of Chemically Modified Electrodes in Analytical Chemistry

“…Even though such modified electrodes resulted in profound electrocatalytic activity, the exact chemical nature of the underlying modified surface was not clearly identified. Ramesh and Sampath improved the modification procedure with a step-by-step solution phase synthetic method from exfoliated graphite ( EC) powder to covalently modified AQ-EC, through monitoring the functionalities with FT-IR and XPS [66]. The AQ-EC powder sample was further modified as a pressed-pellet and utilized for AA detection with surface renewable characteristics.…”

Phenoxazine Functionalized, Exfoliated Graphite Based Electrodes for NADH Oxidation and Ethanol Biosensing

“…EG was then prepared by thermal exfoliation of the graphite-bisulfate intercalation compound at 800 8C [51]. Oxidation/reduction pretreatment of the EG was carried out to introduce phenolic functional groups on the surface as described earlier [51].…”