Cyclic Voltammetry

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Submitted By santinaj7224
Words 259
Pages 2
Santina Cierra Johnson
Junior Seminar
Cyclic Voltammetry

Cyclic Voltammetry
Voltammetry is a category of electroanalytical methods used in chemistry and many industrial processes to obtain information about an analyte by measuring current as a function of applied potential. Cyclic voltammetry (CV) is a method used to understand mechanisms of redox reactions in solution. Cyclic voltammetry provides information on thermodynamics of redox processes and the kinetics of heterogeneous electron transfer reactions. CV looks at current vs potential response of small, stationary electrode in unstirred solution using triangular wave for excitation. A triangular waveform is applied to the working electrode; a linear voltage ramp is applied between t0 and t1 then the ramp is reversed in order to bring the potential back to its initial value at time t2. The current resulting from an applied potential is measured during a potential sweep and a current- potential plot (voltammogram) is obtained. Assuming that a redox active element is initially present, such as, Iron (III), a negative potential sweep results in the reduction of Iron (III) to Iron (II). As potential approaches standard potential (E°) for the redox process, a cathodic current is observed until a peak is reached. The potential sweep direction is reversed after going beyond the region where reduction is observed. Iron (II) molecules generated and near the electrode surface are reoxidized to Iron (III) during the reversed scan, which results in an anodic peak current. The forward and reverse currents have the same shape. Cyclic voltammetry can be useful in studying reaction mechanisms, adsorption processes, and quantitative…...

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