Shrinking nanowires by kinetically controlled electrooxidation

Article abstract of DOI:10.1021/jp056160k

Nanowires composed of antimony, gold, and bismuth telluride (Bi ₂Te₃) were reduced in diameter by electrooxidation in aqueous solutions. When electrooxidation was carried out using low current densities (J_ox < 150 μAcm^-2), the mean wire diameter decreased in direct proportion to the oxidation time, as expected for a kinetically controlled process. Under these conditions, the diameter uniformity of nanowires remained constant as wires were shrunk from initial diameters of more than 120 nm to less than 40 nm, for Sb and Bi ₂Te₃, and less than 60 nm for Au. Oxidized nanowires remained continuous for more than 100 μm. Electrooxidation at higher current densities rapidly introduced breaks into these nanowires. Electrochemical wire growth and shrinking by electrooxidation were integrated into a single electrochemical experiment that allowed the final mean diameter of nanowires to be specified with a precision of 5-10 nm.