Electrochemical Deposition of Silver Nanocrystallites on the Atomically SmoothGraphite Basal Plane

摘要

A potentiostatic pulse method has been employed to electrochemically depositsilver nanocrystallites on the atomically smooth graphite basal plane surface. Voltage pulses having amplitudes of 100, 250, and 500 mV vs. Ag(sup o) and durations of 10 and 50 ms were applied to graphite surfaces immersed in 1.0 mM aqueous AgF. I vs. t transients recorded during the deposition increased in proportion to t(1/2) for all depositions. This behavior is diagnostic of an instantaneous nucleation, and three-D growth mode of deposition. Consistent with this model, non-contact atomic force microscopy (NC-AFM) examination of the graphite surface following deposition revealed the existence of silver particles at a coverage of near 10(exp 10)/sq cm. These particles were disk-shaped having a height of 15 to 50A, and an apparent diameter of 200A to 600 A; these dimensions increased smoothly with the coulometric loading. jg p.2.