Graphene nanoribbons for sensors, supercapacitors
doi:10.1038/nindia.2015.49 Published online 17 April 2015
Researchers have used three-dimensional graphene nanoribbons to produce an electrode that could potentially be used in efficient sensors and supercapacitors1.
The researchers synthesized two-dimensional graphene nanoribbons by chemically cutting multiwalled carbon nanotubes with a strong oxidizing agent such as potassium permanganate in an acidic medium. They deposited these nanoribbons on a glassy carbon electrode and converted them into three-dimensional graphene nanoribbons using a chemical called glutaraldehyde.
The scientists performed electrochemical measurements to probe the efficacies of the three-dimensional nanoribbon-modified electrodes to sense biochemicals and store charge. They compared the results with those for an electrode modified with two-dimensional graphene nanoribbons.
They found that the electrode with three-dimensional nanoribbons exhibited a high peak current and fast charge transfer due to large surface area of the nanoribbons. When dipped in solutions containing ascorbic acid and the neurotransmitter dopamine, the three-dimensional nanoribbon-coated electrode showed a large increase in peak current.
The researchers attribute this current response to the high surface area and fast electron transfer through the network of three-dimensional graphene nanoribbons. The electrode coated with three-dimensional nanoribbons could also store charge, indicating its potential for use in supercapacitors.
“The three-dimensional graphene nanoribbons have been found to aid the oxygen reduction reaction, which is important for triggering electrochemical energy conversion processes in fuel cells and metal–air batteries,” says lead researcher Tharangattu Narayanan.
1. Vineesh, T. V. et al. The improved electrochemical performance of cross-linked 3D graphene nanoribbon monolith electrodes. Nanoscale 7, 6504–6509 (2015)