R. S. Nicholson

Bio: R. S. Nicholson is an academic researcher. The author has contributed to research in topics: Electrochemical reaction mechanism & Electron transfer. The author has an hindex of 1, co-authored 1 publications receiving 271 citations.

A Practical Beginner’s Guide to Cyclic Voltammetry

Abstract: Despite the growing popularity of cyclic voltammetry, many students do not receive formalized training in this technique as part of their coursework. Confronted with self-instruction, students can be left wondering where to start. Here, a short introduction to cyclic voltammetry is provided to help the reader with data acquisition and interpretation. Tips and common pitfalls are provided, and the reader is encouraged to apply what is learned in short, simple training modules provided in the Supporting Information. Armed with the basics, the motivated aspiring electrochemist will find existing resources more accessible and will progress much faster in the understanding of cyclic voltammetry.

Electrochemistry in deep eutectic solvents.

Abstract: We report the cyclic voltammetry, chronoamperometry, and scanning electrochemical microscopy of ferrocene dissolved in deep eutectic solvents (DES), consisting of choline chloride (ChCl) and either trifluoroacetamide (TFA) or malonic acid as the hydrogen-bond donor. Despite the use of ultramicroelectrodes, which were required due to the modest conductivities of the DES employed, linear diffusion behavior was observed in cyclic voltammetric experiments. The high viscosity of 1:2 ChCl/TFA relative to non-aqueous electrochemical solvents leads to a low diffusion coefficient, 2.7 x 10(-8) cm2 s(-1) for ferrocene in this medium. Because of the difficulties in achieving steady-state conditions, SECM approach curves were tip velocity dependent. Under certain conditions, SECM approach curves to an insulating substrate displayed a positive-feedback response. Satisfactory simulation of this unexpected behavior was obtained by including convection terms into the mass transport equations typically used for SECM theory. The observance of positive-feedback behavior at an insulating substrate can be described in terms of a dimensionless parameter, the Peclet number, which is the ratio of the convective and diffusive timescales. Fitting insulator approach curves of ferrocene in 1:2 ChCl/TFA shows an apparent increase in the diffusion coefficient with increasing tip velocity, which can be explained by DES behaving as a shear thinning non-Newtonian fluid.

Cyclovoltammetrie — die „Spektroskopie”︁ des Elektrochemikers

Abstract: Unter den klassischen Mesmethoden der elektroanalytischen Chemie geniest die Polarographie noch immer den hochsten Bekanntheitsgrad. In den letzten Jahren wurde ihr diese Position allerdings zunehmend von der Cyclovoltammetrie streitig gemacht. Einfach anzuwendende diagnostische Kriterien und eine relativ leicht zugangliche Mestechnik haben diese Entwicklung begunstigt. Die Attraktivitat der Methode resultiert weiterhin daraus, das sich aus Cyclovoltammogrammen neben Informationen uber die Thermodynamik von Redoxprozessen auch Kenntnisse uber die Kinetik von heterogenen Elektronentransferreaktionen sowie von angekoppelten chemischen Reaktionen erhalten lassen. Die charakteristischen Formen der Cyclovoltammogramme und die eindeutigen Potentiallagen der Peaks, die nahezu „fingerprint”-artig die elektrochemischen Eigenschaften von Redoxsystemen widerspiegeln, haben der Methode den Beinamen „elektrochemische Spektroskopie” eingetragen.

Improved Electrochemistry in Low-Polarity Media Using Tetrakis(pentafluorophenyl)borate Salts as Supporting Electrolytes.

Abstract: Das nichtkoordinierende Anion [B(C6F5)4]− macht Kationen und Polykationen loslich und ermoglicht so die Bildung und Untersuchung solcher Systeme in Medien mit niedriger Dielektrizitatskonstante. Mit [NBu4][B(C6F5)4] als Leitsalz konnen cyclovoltammetrische Messungen in aliphatischen Ethern und anderen Losungsmitteln sehr niedriger Polaritat durchgefuhrt werden.