Study by cyclic voltammetry of a reversible surface charge transfer reaction when the reactant diffuses to the electrode

Garrido, J. A.; Rodrı́guez, Rosa Marı́a; Bastida, R.M.; Brillas, Enric

doi:10.1016/0022-0728(92)80033-z

Cited by 21 publications

(6 citation statements)

References 8 publications

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“…Some extra studies were carried out to investigate the adsorption phenomena according to literature 25,26 . As a result, the value of the ratio of cathodic peak current to concentration (i p,c /C) decreases with increasing concentration, value of the ratio of cathodic peak current to multiplication of concentration and scan rate (i p,c /Cν) decreases at the beginning and then nearly constant with increasing scan rate, and value of the ratio of cathodic peak current to multiplication of concentration and square root of scan rate (i p,c /Cν 1/2 ) increases with increasing scan rate.…”

Section: Electrochemical Behavior Of Rpnmentioning

confidence: 99%

Square-wave cathodic adsorptive stripping voltammetry of risperidone

Çakirer

Erk

Kılıç

2011

Collect. Czech. Chem. Commun.

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Electrochemical properties and diffusion-adsorption behavior of risperidone (RPN), an antiphyscotic drug, on hanging mercury drop electrode (HMDE) were carried out in BrittonRobinson (BR) buffer. Some electrochemical parameters such as diffusion coefficient, number of transferred electrons and proton participated to its reduction mechanism and surface coverage coefficient were calculated from the results of cyclic voltammetry, square-wave voltammetry and constant potential electrolysis. RPN was found to be reduced with single two-electron/two-proton quasi-reversible mechanism controlled mainly by adsorption with some diffusion contribution at the potential about -1.58 V (vs Ag|AgCl electrode). Experimental parameters were optimized to develop a new, accurate, rapid, selective and simple square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) method for direct determination of RPN in pharmaceutical dosage forms, spiked human urine and human serum samples without time-consuming steps prior to drug assay. This method was based on the relation between the peak current and the concentration of RPN and it was recognized that peak current of reduction wave linearly changes with the concentration of RPN in the concentration range of 1.5-150 nM, when optimum preconcentration potential -0.65 V and optimum preconcentration time 60 s were applied. In this method, limit of detection (LOD) was found as 5.18 nM (2.12 ppb). The method was successfully applied to determine the RPN content of commercial pharmaceutical preparations, spiked human serum and spiked human urine. The method was found to be highly accurate and precise, having a relative standard deviation of less than 4.80% for all applications.

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Section: Electrochemical Behavior Of Rpnmentioning

confidence: 99%

Square-wave cathodic adsorptive stripping voltammetry of risperidone

Çakirer

Erk

Kılıç

2011

Collect. Czech. Chem. Commun.

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“…These slopes close to 0.5 are characteristic of the diffusion-controlled process, otherwise those close to 1 are ascribed to the adsorption-controlled process. 62,63 These results indicate that the electron transfer process could be controlled by adsorption for UA, and by both the diffusion and adsorption control for XA, HX, and CA.…”

Section: ■ Results and Discussionmentioning

confidence: 80%

Polythiophene-wrapped Chitosan Nanofibrils with a Bouligand Structure toward Electrochemical Macroscopic Membranes

Dang,

Le,

Duc Cuong

et al. 2024

ACS Omega

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Exploring structural biomimicry is a great opportunity to replicate hierarchical frameworks inspired by nature in advanced functional materials for boosting new applications. In this work, we present the biomimetic integration of polythiophene into chitosan nanofibrils in a twisted Bouligand structure to afford free-standing macroscopic composite membranes with electrochemical functionality. By considering the integrity of the Bouligand structure in crab shells, we can produce large, free-standing chitosan nanofibril membranes with iridescent colors and flexible toughness. These unique structured features lead the chitosan membranes to host functional additives to mimic hierarchically layered composites. We used the iridescent chitosan nanofibrils as a photonic platform to investigate the host–guest combination between thiophene and chitosan through oxidative polymerization to fabricate homogeneous polythiophene-wrapped chitosan composites. This biomimetic incorporation fully retains the twisted Bouligand organization of nanofibrils in the polymerized assemblies, thus giving rise to free-standing macroscopic electrochemical membranes. Our further experiments are the modification of the biomimetic polythiophene-wrapped chitosan composites on a glassy carbon electrode to design a three-electrode system for simultaneous electrochemical detection of uric acid, xanthine, hypoxanthine, and caffeine at trace concentrations.

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“…For the prewave, a slope is 0.58 ± 0.02 was measured (Figure A, Figure S11B), which is statistically larger than 0.5, but not close to 1. This result indicates that the electrochemical reaction of the prewave is related to weak adsorption of the complex onto the electrode surface, but the prewave likely combines a small portion of weak adsorption and a significant amount of solution diffusion process. − Therefore, the electrochemical reaction of the prewave can be written as the reduction of the mostly free and weakly adsorbed ground state, GS WE , to generatre 1eH′ , where the product of prewave is labeled 1eH′ to distinguish it from 1eH , where the latter only has contributions from the diffusion controlled process. It is likely that GS WE is in fast equilibrium with the GS Rh-bncn complex in the bulk solution, leading to a strong diffusion controlled component.…”

Section: Results and Discussionmentioning

confidence: 99%

Electrochemical Strategy for Proton Relay Installation Enhances the Activity of a Hydrogen Evolution Electrocatalyst

et al. 2022

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A new method to install a proton relay that enhances the reactivity near an active catalytic site for H2 production is reported, afforded by the electrochemical reduction and protonation of one of the ligands in the paddlewheel Rh2(II,II) hydrogen evolution complex, cis-[Rh2(DPhF)2(bncn)2]2+ (Rh-bncn; DPhF = N,N′-diphenylformamidinate, bncn = benzo[c]cinnoline). An electrochemical reversible prewave is observed for Rh-bncn at potentials more positive than the first bncn-centered reduction couple in the presence of strong acids, observed at −0.72 V vs Fc+/0 (Fc = ferrocene) in the cyclic voltammograms (CVs) in DMF (0.1 M TBAPF6). The origin of this prewave is shown to arise from a precatalytic transformation that originates from a concerted proton–electron transfer (CPET) event occurring at one of the bridging bncn ligands. Through electrochemical analysis, CV simulations, and electronic structure calculations, a reaction mechanism is elucidated. In this system, the electrochemically formed N–H bond on the reduced bncn ligand serves as a proton relay in the H2 formation reaction through a cooperative interligand pathway involving one of the bridging DPhF ligands after a second reduction step, accessible at approximately −1.15 V vs Fc+/0. Since calculations show that hydrogen evolution takes place at the bridging ligands and does not involve the dirhodium core, it is predicted that more abundant metal centers can be incorporated into this ligand scaffold, leading to new candidates for electrocatalytic hydrogen reduction. As such, this work delineates a new design strategy to incorporate proton relays in molecular bimetallic hydrogen evolution electrocatalysts to achieve higher efficiency.

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Study by cyclic voltammetry of a reversible surface charge transfer reaction when the reactant diffuses to the electrode

Cited by 21 publications

References 8 publications

Square-wave cathodic adsorptive stripping voltammetry of risperidone

Square-wave cathodic adsorptive stripping voltammetry of risperidone

Polythiophene-wrapped Chitosan Nanofibrils with a Bouligand Structure toward Electrochemical Macroscopic Membranes

Electrochemical Strategy for Proton Relay Installation Enhances the Activity of a Hydrogen Evolution Electrocatalyst

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