Nanoparticle Synthesis at ITIES

One property of liquid-liquid interfaces in general, and of ITIES in particular, is their ability to adsorb nanoparticles and, in certain cases, to form metal-like films. Pioneering measurements were carried out by Guainazzi et al. [330] who demonstrated that a direct current applied across the interface between Cu ion in water and a vanadium complex in 1,2- DCE causes deposition of a copper layer at the liquid-liquid boundary. Another seminal work is that of Efrima et al. who showed in 1988 the formation of silver metal-like films at the HjO-DCE interface [331], Since then, many publications have addressed this fascinating topic, and the field was excellently reviewed recently by Boerker et al. [332]. 

More specifically at ITIES, a lot of effort has been dedicated to nucleation and growth of nanoparticles for electrocatalytic studies. In 1998, Schiffrin deposited gold particles at an ITIES by electrochemical reduction of tetraoctylammonium tetrachloroaurate in 1,2-DCE using ferrocyanide in water as the electron donor. Their growth was monitored in situ by transmission UV-VIS spectroscopy, and the spectra have been qualitatively analyzed using Mie s theory [331]. The nucleation mechanism was later addressed by Johans et al. [334,335] using dibutyl- 

FIGURE 1.36 (a) nucleation and growth scheme, (b) cyclic voltammograms obtained 

Dryfe et al. extended this study by depositing Pd and Pt nanoparticles on ITIES supported on porous alumina so as to control the mass transport conditions and prevent nanoparticle aggregation [337-343], Cunnane and his group have shown that nanoparticle deposition could be carried out concomitantly with a polymerization process so as to obtain well-dispersed NPs [344-346], 

Recently, Rao and his gronp have shown that beantifnl fractal strnctnres conld be formed at ITIES when nsing snrfactants to control the growth process (Fignre 1.37) [347]. 

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