Influence of Substrate, Additives, and Pulse Parameters on Electrodeposition of Gold Nanoparticles from Potassium Dicyanoaurate

Abstract

Gold nanoparticles (AuNPs) of less than 50 nm diameter were electrodeposited from cyanide solution by pulsating electric current on modified copper and indium tin oxide (ITO) films coated on glass. Morphology, size, and composition of the deposited AuNPs were studied by X-ray photoelectron spectroscopy, atomic force microscopy, and field emission scanning electron microscopy. Effects of peak current density, pulse frequency, potassium iodide and cysteine on grain size, and morphology of the AuNPs were determined. Experiments showed that cathode current efficiency increases with the pulse frequency and the iodide ion. Size of the AuNPs increased with the current density. The number of nucleation sites was larger on ITO than on Cu layer; while the average diameter of the crystallites on ITO was smaller than on Cu layer.

Electrodeposition of Nanoporous Gold Thin Films

“…Conductive substrates coated with AuNPs can be exploited as biochemical sensors and electrodes owing to their excellent electrocatalytic activity. A simple, powerful, and cost-effective way for attachment of AuNPs onto a substrate has been electrodeposition with pulsating current resulting in smoother, brighter, finer, and less porous Au grains concerning the direct current [48]. A simple template-less, surfactant-less and effective electrochemical method for the preparation of AuNP arrays with an average diameter of ~14 nm onto indium tin oxide (ITO) glass has been reported.…”

Recovery of Gold as Nanoparticles from Gold-Poor Au-Cu-Cl Solutions

“…Since gold and copper are often found together in ores in varying ratios, the capability of chloride to effectively leach copper ores increases the utilization potential of this method on industrial scale. , Due to the variation in raw material, the gold concentration may often be too low for its viable recovery. However, value may be found by using a single recovery step to directly create a functional surface, as gold can be deposited electrochemically as nanoparticles, , which have found applications especially in catalysis − and chemical sensing. − Compared to producing bulk metals, nanostructures typically require relatively low amounts of metal and therefore may be able to better take advantage of resource streams where the concentrations are low.…”