| Abstract
| - By applying a seed-mediated growth method that had been reported for the chemical synthesis of Ag nanorodsand nanowires in aqueous solution, we successfully attached Ag nanosphere and nanorod particles to indiumtin oxide (ITO) surfaces. In this method, it is characteristic that the attachment can be performed withoutusing bridging reagents, such as 3-mercaptopropyltrimethoxysilane, but rather through a two-step immersioninto the seed solution first and then into the growth solution containing AgNO3, cetyltrimethylammoniumbromide, and ascorbic acid. It was found that the formed nanostructures were very sensitive to the amount ofascorbic acid in the growth solution. Whereas Ag nanoparticles grew on the ITO surface with a moderatedispersion when the concentration of ascorbic acid in the growth solution was 0.64 mM, the formation ofnanorods and nanowires was observed when the ascorbic acid concentration was increased to 0.86 mM. Theattachment of Ag nanoparticles onto the ITO surfaces was strong enough for further use, e.g., as a workingelectrode. From electrochemical measurements, it was confirmed that the outer spheres of the Ag nanoparticlesinvolved in the redox reaction show the typical oxidation and reduction waves of Ag. In addition, the redoxbehavior of [Fe(CN)6]3-/[Fe(CN)6]4- was improved on the Ag-nanoparticle-attached ITO (AgNP/ITO) electrode,reflecting the low electron-transfer resistivity, which is a remarkable advantage of the present fabricationwithout using bridging reagents. This result indicated that the Ag nanoparticles promote the electron-transferreactions by being present on the conducting ITO surface. The AgNP/ITO electrode was examined for thereduction of the methyl viologen dication in order to discuss some features of the present fabrication.
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