Electrochemical synthesis of hexadecyltrimethylammonium-coated Ag nanopeanuts and their self-assembly to nanonets

A novel and simple electrochemical method for preparing Ag nanopeanuts has been developed. These peanut-shaped nanoparticles are electroreduced in an aqueous solution containing adsorbed hexadecyltrimethylammonium ions (CTA+) without a counter ion, Br−. For electroreduction, the electrical double layer of CTA+ micelle has to be regulated. As the aging time increases, the structure of the CTA+ micelle changes; this causes the Ag nanopeanuts to assemble via a one-dimensional (1-D) process. Finally, Ag nanonets are obtained. Linear assembly results in a change in the optical properties, such as a red shift in the longitudinal surface plasmon resonance band. Additionally, as an information supported by electrochemical measurement, the newly Ag nanonets as alcohol-tolerant catalysts show high activity toward oxygen reduction.