Asep Rohiman1*, Isa Anshori1, Akhmadi Surawijaya 1,2 and Irman Idris1,2
1 Microelectronics Center, Bandung Institute of Technology
2 School of Electrical Engineering and Informatics, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132 – Indonesia
* Email: firstname.lastname@example.org
The synthesis of colloidal gold or Au-nanoparticles (Au-NPs) by reduction of chloroauric acid (HAuCl4) with sodium citrate was done using Turkevich method. We prepared HAuCl4 solution by dissolving gold wires (99.9%) into aqua regia solution. To initiate the Au-NPs synthesis 0.17 ml of 1 % chloroauric acid solution was heated to the boiling point and then 10 ml of 1 % sodium citrate was added to the boiling solution with a constant stirring in order to maintain a homogenous solution. A color of faint gray was observed in the solution approximately one minute and in a period of 2 – 3 minutes later, it further darkened to deep wine and red color. It showed that the gold solution has reduced to be Au-NPs. The effect of process temperature on the size of Au-NPs prepared by sodium citrate reduction has also been investigated. With increasing temperature of Au-NPs synthesis, smaller-size Au-NPs were obtained. The higher temperatures shorten the time needed to achieve activation energy for reduction process. The resulting Au-NPs has been characterized by Scanning Electron Microscope (SEM), showing the size of Au-NPs average diameter is ~24-27 nm. The resulting colloidal gold will be used as a catalyst for Si nanowires growth using VLS method.
Keywords: colloids, gold nanoparticles, energy activation, catalyst
Puplished : AIP ( American Institute of Physics)