Investigation of interparticle interactions of larger (4.63 nm) monolayer protected gold clusters during quantized double layer charging

Abstract

In this article, the effect of interparticle interactions of 4.63 nm sized monolayer protected gold clusters (Au MPCs) during quantized double layer (QDL) charging has been investigated using electrochemical techniques. Voltammetry and scanning tunneling microscopy have been used to compare their electron transfer behavior. Furthermore, since the QDL process is diffusion controlled, the diffusion coefficient values have been estimated at various charge steps using two independent electroanalytical techniques, viz. chronoamperometry and impedance. These results show that higher core charge facilitates higher diffusion coefficient values, and indicate that repulsive interactions dominate for charged MPCs compared to those of its neutral analogue, which are mainly attractive in nature. Additionally, the electron transfer rate constants at various charge steps have been estimated from the impedance results, showing comparatively faster electron transfer rate at higher charge states.

Quantized Double‐Layer Charging of Rhodium2057(Tridecylamine)321 Clusters Using Differential Pulse and Cyclic Voltammetry

“…[1][2][3][4] In addition, earlier reports have demonstrated QDL-charging behavior of larger-core clusters (e.g., Au 1400 , Au 2869 ), where surface adsorption plays an important role. [5][6][7] Also, much of the effort aimed at observing the QDL charging of smaller monolayer-protected clusters (MPCs) (1-2 nm) has involved the use of gold particles, with a few exceptions such as Ag, [8] Pd, [9] and Cu, [10] and semiconducting systems such as Si [11] and CdTe.[12]Most of the reports have discussed the synthesis of smaller metal particles and their electrochemical properties, suggesting a tiny-capacitor model for metal nanoclusters that show multiple peaks in voltammetric experiments, corresponding to QDL charging (a single-electron-transfer phenomenon in this size regime). STM studies under high vacuum at 83 K also reveal a reversible "Coulomb blockade" (CB) phenomenon, with multiple equidistant charging steps with different bias.…”

Associative Memory Based on Double-Gating of Molecularly Linked Nanosystem Arrays: A Theoretical Scheme

“…Note that 1 aF is the typical nanoparticle capacitance for a monolayerprotected metallic cluster. [11][12][13]29 The nanowire resistances for the conducting polymers of ref 27 The maximum potentials attained for each array i ) 1, 2, ..., N at sufficiently long times could be compared to a prescribed potential lower than V d . The capacitor that reaches this prescribed potential at a shorter time corresponds to the pattern i most similar to the input pattern (the number 5 in Figures 6 and 7).…”

Biologically Inspired Information Processing and Synchronization in Ensembles of Non-Identical Threshold-Potential Nanostructures

“…This system can be realized experimentally by means of ligand-stabilized metallic nanoparticles [2], [18], [19], [28], [29]. The nanoparticle (NP) is functionalized with an organic ligand acting as a tunneling junction and the single electron transfers between the NP and the external electrode are determined by the Coulomb blockade and tunneling effects [2], [18], [19], [28], [29]. These electron transfers lead to measurable electric potential changes of the order of 100 mV for effective NP capacitances of the order of 1 aF [2], [19], [22], [28], [29].…”

“…The nanoparticle (NP) is functionalized with an organic ligand acting as a tunneling junction and the single electron transfers between the NP and the external electrode are determined by the Coulomb blockade and tunneling effects [2], [18], [19], [28], [29]. These electron transfers lead to measurable electric potential changes of the order of 100 mV for effective NP capacitances of the order of 1 aF [2], [19], [22], [28], [29]. For example, the electrochemically determined capacitance of Au 225 (diameter 1.8 nm) is 0.6 aF approximately [30] and other particles like Pd 40 (diameter 1.2 nm) show a capacitance as low as 0.35 aF.…”