Quantized capacitive charging

S. Chen R. W. Murray, Electrochemical Quantized Capacitance Charging of Surface Ensembles of Gold Nanoparticles. J. Phys. Chem. B 1999, 103, 9996-10000. 

Quantized electrochemical capacitive charging of variable-size AuNP monolayers with protective monolayer coatings in aqueous and organic solvents has been reported [272, 283]. A recent study reported in situ STM and Coulomb... 

Chen, S.W. and Murray, R.W. (1999) Electrochemical quantized capacitance charging of surface ensembles of gold nanopartides. Journal of Physical Chemistry B, 103, 9996-10000. 

Chen S, Murray RW, Feldherg SW. 1998. Quantized capacitance charging of monolayer-protected Au clusters. J. Phys. Chem. B 102 9898-9907. 

Chen, S. W., Murray, R. W., Feldherg, S. W. Quantized capacitance charging of monolayer-protected An clusters. J Phys Ghent B 1998,102, 9898-9907. 

Solution-phase DPV of Au144-C6S dispersed in 10 mM [bis(triphenylpho-sphoranylidene)-ammoniumtetrakis-(pentafluorophenyl)-borate (BTPPATPFB)/ toluene] [acetonitrile] 2 1 revealed well-behaved, equally spaced and symmetric quantized double-layer charging peaks with AE - 0.270 0.010 V. Applying the classical concentric spheres capacitor model (8) reveals an individual cluster capacitance of 0.6 aF [334, 335]. 

Other metallic clusters that have been demonstrated to show the QDL effect are palladium [116, 117], silver [118] and copper [119]. Palladium MFCs capped with mixed monolayers of hexanethiolate/dodecanethiolate and ferrocene thiolate ligands are prepared in a manner similar to that employed for gold MFCs. The DPV studies exhibit a quantized charging effect but the current peaks are not as well defined as those observed for Au-MPCs. Capacitance values of the order of 0.35 aF are obtained, indicating smaller core sizes or thicker monolayer dielectrics [116]. 

When making electrodes on the order of a few nanometers in diameter, as required for these cells, quantized double-layer charging must be addressed. With these small devices, electrons are not added continuously as a function of potential. Rather, electrons are added in discrete steps at different potentials as a consequence of the extremely small capacitance of the particle. 

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