A mechanistic model for the electrochemical facetting of metals with development of preferred crystallographic orientations

Abstract

A model for the development of surface profiles of face-centred cubic metals which can be related to the electrochemical facetting with preferred, oriented crystallographic planes, is proposed and simulated by means of the Monte Carlo method. Successive cycles of selective electrodissolution and electrodeposition under a periodic potential are simulated through the withdrawal and attachment of particles to the metal profile according to specified rules which are supported by experimental observations. The model is applied to the development of two different crystallographic faces starting from either perfectly-ordered void-free profiles (single crystal approach) or a rough profile with defects in the bulk (polycrystal approach). The simulation results are in qualitative agreement with electrochemical facetting data, scanning electron microscopy and scanning tunneling microscopy images of various face-centred cubic metals.

Monte Carlo Simulation of a Model for Growth Kinetics and Growth Mode of Metals Through Hydrous Metal Oxide Layers Electroreduction. Applications to Gold Overlayers

“…Other workers subsequently deposited InP and GaAs from similar systems, although not epitaxially (9,10). Recently, Wicelinski and Gale (12) have reported the electrodeposition of GaAs at even lower temperatures (40~ from acidic chloroaluminate melts composed of A1C13 and 1-butylpyridinium chloride. Recently, Wicelinski and Gale (12) have reported the electrodeposition of GaAs at even lower temperatures (40~ from acidic chloroaluminate melts composed of A1C13 and 1-butylpyridinium chloride.…”

“…The SE corresponds to a twodimensional (2-D) cross section of the actual three-dimensional (3-D) fcc electrode. Each site of the i-th layer has a probability P(i) to be occupied given by (11,12) that is the SE is simulated by assuming a full occupancy in the first L1 layers, while the subsequent L'I layers are filled in with a linear concentration gradient such as P(i = L1) = 1 and P(i = L1 + L'l) = p, where L'I, and p =< t are adjustable parameters. 1 are parallel to the [110] and the [110] directions in the 3-D lattice, respectively.…”

Selective conversion of CO into ethanol on Cu(511) surface reconstructed from Cu(pc): Operando studies by electrochemical scanning tunneling microscopy, mass spectrometry, quartz crystal nanobalance, and infrared spectroscopy

“…A few remarks are essential to understand the voltammetric scheme used to generate Cu(pc)-[Cu(511)]. Classic electrochemical procedures for the development of preferred crystallographic orientation on face-centered cubic metals employ rapid iterations, at a frequency of a few kHz, of electrodissolution and electrodeposition [22]. The present preparative route intentionally excludes the formation Cu(II) and its oxides and hydroxides, which are reported to redeposit copper as islands and nanostructured assemblies [23].…”

Potentiostatic and Potential Cycling Dissolution of Polycrystalline Platinum and Platinum Nano-Particle Fuel Cell Catalysts

“…[1][2][3][4][5][6][7][8][9][10][11][12] Early studies of platinum dissolution in electrochemical systems were motivated by the desire to determine the origins of the evolution of the voltammetric signature of platinum electrodes with potential cycling, 3 termed "electrochemical activation", and of the faceting of polycrystalline platinum with rapid potential cycling and stepping. 13 More recently, studies have emerged related to the potentiostatic and potential cycling dissolution of polycrystalline platinum, 4,[14][15][16][17] single crystal platinum, 18 platinum black, 19 nano-particle films, [20][21][22] and of nano-particle platinum supported on high surface area carbon (Pt/C). 17,[23][24][25][26][27] These studies were motivated by the desire to determine the origins of the observed loss of electrochemically-active surface area (ECA) of phosphoric acid fuel cell and polymer electrolyte fuel cell (PEFC) electrocatalysts, as this is a dominant cause of irreversible loss of Pt/C-based cathode performance.…”