showing 5 related works from this author
Variation of the Fermi level and the electrostatic force of a metallic nanoparticle upon colliding with an electrode.
2017
When a metallic nanoparticle (NP) comes in close contact with an electrode, its Fermi level equilibrates with that of the electrode if their separation is less than the cut-off distance for electron tunnelling. In the absence of chemical reactions in solution, the charge on the metallic nanoparticle is constant outside this range before or after the collision. However, the double layer capacitances of both the electrode and the NP are influenced by each other, varying as the function of distance. Because the charge on the nanoparticle is constant, the outer potential of the metallic NP and hence its Fermi level varies as the capacitance changes. This effect is more pronounced for small part…
Understanding Digestive Ripening of Ligand-Stabilized, Charged Metal Nanoparticles
2017
Most syntheses of thiolate-protected metal nanoparticles (NPs) include a thermochemical step in which the as-prepared, polydisperse NPs are transformed to a narrower size distribution in a poorly understood process known as digestive ripening (DR). Previous theoretical approaches considered either surface and electrostatic contributions or surface and ligand-binding contributions. We show that the three contributions are needed to obtain theoretical predictions in agreement with experimental observations. Although statistical thermodynamics does not clarify mechanistic details, it certainly provides valuable insights on the DR process. Remarkably, a relatively simple theory with no fitting …
Contact Potentials, Fermi Level Equilibration, and Surface Charging.
2016
This article focuses on contact electrification from thermodynamic equilibration of the electrochemical potential of the electrons of two conductors upon contact. The contact potential difference generated in bimetallic macro- and nanosystems, the Fermi level after the contact, and the amount and location of the charge transferred from one metal to the other are discussed. The three geometries considered are spheres in contact, Janus particles, and core-shell particles. In addition, the force between the two spheres in contact with each other is calculated and is found to be attractive. A simple electrostatic model for calculating charge distribution and potential profiles in both vacuum an…
Correction: Variation of the Fermi level and the electrostatic force of a metallic nanoparticle upon colliding with an electrode.
2017
The nanoparticle potential varies with the distance from the electrode, and sometimes like attracts like.
Biomimetic oxygen reduction by cofacial porphyrins at a liquid-liquid interface.
2012
Oxygen reduction catalyzed by cofacial metalloporphyrins at the 1,2-dichlorobenzene−water interface was studied with two lipophilic electron donors of similar driving force, 1,1'-dimethylferrocene (DMFc) and tetrathiafulvalene (TTF). The reaction produces mainly water and some hydrogen peroxide, but the mediator has a significant effect on the selectivity, as DMFc and the porphyrins themselves catalyze the decomposition and the further reduction of hydrogen peroxide. Density functional theory calculations indicate that the biscobaltporphyr- in, 4,5-bis(5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl))-9,9-dimethylxanthene, Co2(DPX), actually catalyzes oxygen reduction to hydrogen p…