(668h) Electrochemical Synthesis of Organic Nanorods on Gold Nanoparticles Seeds

This talk focuses on the synthesis of tetrathiafulvalene bromide charge-transfer salt (TTFBr) and copper tetracyanoquinodimethane (CuTCNQ) organic nanorods directed by gold nanoparticles (GNPs) using electrochemical methods. GNPs, working as seeds, were first deposited on highly oriented pyrolytic graphite (HOPG). The nanorods, either TTFBr or CuTCNQ, were the deposited on the GNP decorated HOPG. All the depositions were done by applying pulses of overpotentials. Cyclic voltammetry (CV), field emission scanning electron microscope (FESEM) and in-situ atomic force microscope (AFM) were employed to monitor the deposition process. The TTFBr and CuTCNQ nanords deposited on GNP-decorated HOPG showed preferential nucleation on GNP comparing with crystals electrochemically deposited on the planar HOPG. The morphology of the organic crystals was confined and controlled by the GNP size and shape. Nanorods as small as 7 nm in height were nucleated on GNP of 20 nm in height. This electrocrystallization method was also applied to deposit organic nanords on photolithographic patterns to produce nanosensors for gas sensing. This research addresses both a fundamental question concerning the smallest seed required for heterogeneous crystallization as well as market needs for portable and networkable gas sensors. This work is supported by the National Science Foundation.