Application of Ion Implantation to the Study of Electrocatalysis: I . Chlorine Evolution at Ru‐Implanted Titanium Electrodes

Abstract

Ru-implanted titanium near-surface alloys were generated by ion implantation, characterized (Ru concentration/ depth profiles) by Rutherford backscattering, and subsequently anodically oxidized to form electrocatalytically active RuxTil_xOJTi electrodes. The electrochemical behavior of the metallic-like electrodes was investigated in acidic chloride, perchlorate, and sulfate media. A correlation between the rate of the C12 evolution reaction and the Ru-implant profiles established that the reaction is first order in the concentration of Ru(IV) in the oxide at the oxide/solution interface, and enabled an in situ evaluation of the latter quantity. The Tafel slope for the C12 evolution reaction is 40 mV, i.e., o E/O log i = 2.303 (2RT/3F). The reaction order with respect to chloride ion concentration, 0 log i/0 log [C1-], approaches 1.0 and 2.0 at high and low chloride Concentrations, respectively. A modified Volmer-Heyrovsky mechanism, one in which the role of adsorbed chloride ions is taken into account, is shown to be consistent with the aforementioned diagnostic parameters.ion implantation, a nonequilibrium doping technique, enables the controlled introduction of virtually any element into the near-surface region of any substrate, typically to a depth up to a few hundred nanometers. The concentration/depth profile of the implanted species (determined, for example, by Rutherford backscattering) *Electrochemical Society Active Member. may be tailored over a wide range by varying the energy of the incident ions and the number of ions (coulombs of charge) implanted at each energy. As a surface modification technique, ion implantation has found widespread application for improving the electronic, optical, tribological, and corrosion characteristics of materials (1-4). The rates of many technologically important electrochemical charge transfer reactions occurring at elec-) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.255.6.125 Downloaded on 2015-06-03 to IP

Structural, electrical and catalytic properties of ion-implanted oxides

“…Electrocatalytic studies in the liquid phase have been performed by Schultze et al [47,48], Kelly et al [59] and Wolf et al [49,60,61].…”

“…Metallic conducting RuxTil-xO2 layers could be prepared by ion implantation of Ru in Ti metal electrodes and subsequent anodic oxidation [59]. Ion implantation was chosen to prepare those layers in order to circumvent the lateral inhomogeneous nature of conventionally prepared RuxTil_xO2 electrodes.…”

“…The localized electronic states introduced by the implantation of Pd ions were more active in electron transfer reactions 38 B.A. van Hassel and A. J. Burggraaf (Fe 2 +/Fe 3+, Ce4+/Ce 3+, H+/H2, and HzO/02) than the localized electronic states introduced by the radiation damage processes.Metallic conducting RuxTil-xO2 layers could be prepared by ion implantation of Ru in Ti metal electrodes and subsequent anodic oxidation [59]. Ion implantation was chosen to prepare those layers in order to circumvent the lateral inhomogeneous nature of conventionally prepared RuxTil_xO2 electrodes.…”

Rational Surface and Interfacial Engineering of IrO2/TiO2 Nanosheet Arrays toward High‐Performance Chlorine Evolution Electrocatalysis and Practical Environmental Remediation

“…From recent theoretical studies, [ 9b,14 ] three potential reaction mechanisms for the CER have been well described according to the indirect experimental results of Tafel slopes and reaction orders. [ 15 ] The possible rate‐determining steps (RDS) include the Volmer–Tafel reaction (Equation ()), [ 16 ] Volmer–Heyvrosky reaction (Equation ()), [ 17 ] and Khrishtalik reaction (Equation ()). [ 18 ] Herein, * is an active site, which may be the metal atom or surface oxygen.…”

Enhancement of ion transmission and reduction of background and interferences in inductively coupled plasma mass spectrometry

“…One such project involves continuously modifying the electrochemical properties of metal oxide electrodes by doping them with small amounts of impurities metal ions, such as Bi or Sb. It was reported that electrocatalysis could be studied by ion implantation (105). Some interesting studies in electrocatalysis can be done with the ICP-MS ion implantation system because mixtures of different elements can be deposited easily in any desired stoichiometry by introducing a multielement sample into the plasma.…”