Reduction of Metals in Liquid Solutions

The reductive deposition of silver and copper ions on (oxygen-removed and hydrogen-terminated) SiNW surfaces in a solution was investigated [76] as an alternative method to ion implantation. The SiNWs surface is indeed capable of reducing silver and cooper ions to metal aggregates of various morphologies at room temperature. 

The silver metal deposition on SiNWs in different concentrations of silver solution (10 to 0.1 M) was studied in detail with SEM, EDS, and XPS. The SEM images show that the morphology of the deposited silver depends on the concentration of silver nitrate. At high concentrations the redox reaction is controlled by the concentration of Ag ions (mass action), so that large quantities of Ag ions in the vicinity of SiNWs are reduced and aggregated as dendrites. At low concentrations, the conditions required for dendrite formation are not reached and silver is de- 

M silver nitrate treated SiNWs. Note the oxidation of the Si associated with the reduction of the silver ions [76]. 

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