Chandra, Shaneel and Tupiti, Wycliff and Singh, Sevlin and Naaz, Zafiar and Kishor, Pritika K. and Goundar, Archana and Fakraufon, Malina and Prasad, Surendra
(2016)
An Undergraduate-Level Electrochemical Investigation of Gold Nanoparticles-Modified Physically Small Carbon Electrodes.
World Journal of Chemical Education, 4
(5).
pp. 93-100.
ISSN 2375-1665
Abstract
This paper reports an undergraduate experiment based on analytical chemistry, electrochemistry and materials science of carbon microelectrodes. The modification of the electroactive surface of the carbon microelectrode was done using gold nanoparticles electrodeposited from gold solution. To determine the changes on the surface, the electrode was subjected to simple optical microscopy. Next, the electrode was characterized using fast-scan cyclic voltammetry of two known electrochemical redox markers: hexaamineruthenium(III) chloride and potassium hexacyanoferrate (III), i.e. potassium ferricyanide. The redox behavior of both markers demonstrated the change in electrode surface. After modification, the ferricyanide reduction peaks were observed to increase significantly, as a consequence of accelerated electron transfer. Furthermore, changes in wave slope and half-wave potentials (E1⁄2) of the redox waves also confirmed an altered electrode surface that students can logically trace back to the modification. The electrode tip dimension was also determined using a modified form of the Cottrell equation, confirming the tip size to be 2.0 μm. The discussion of these results enables an understanding of electrochemistry, analytical chemistry and materials chemistry, and presents an excellent opportunity to apply these in an undergraduate setting.
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