Microdisk electrodes. Part II. Fast-scan cyclic voltammetry with very small electrodes

Abstract Cyclic voltammetry has been investigated at inlaid disk electrodes with nominal radii of 0.3, 1.0, and 5.0 μm. The electrode capacitance is found to be much larger than expected for the two smaller radii electrodes. This effect is attributed to the capacitance between the inner conductor and the electrolyte solution. The excess capacitive current is minimized by the use of a conductive shield around the electrode which is connected to ground potential. Criteria are investigated for the degree of filtering of steady-state voltammograms to minimize noise while avoiding distortion of the experimental data. Experimental voltammograms for the oxidation of ferrocene in acetonitrile solutions are found to be in good agreement with existing theories for scan rates in which linear and convergent diffusion occur. The factors which limit the use of very small electrodes are discussed in terms of signal-to-noise, ohmic drop, and linear diffusion.

[1]  D. A. Sweigart,et al.  Fabrication of platinum-disk ultramicroelectrodes. , 1988, Analytical chemistry.

[2]  K. B. Oldham,et al.  Measurement of ultrafast electrode kinetics via steady-state voltammograms at microdisc electrodes , 1988 .

[3]  C. Amatore,et al.  Nanosecond time resolved cyclic voltammetry: Direct observation of electrogenerated intermediates with bimolecular diffusion controlled decay using scan rates in the megavolt per second range , 1987 .

[4]  R. S. Robinson,et al.  Submicrosecond spectroelectrochemistry applied to chlorpromazine cation radical charge transfer reactions , 1985 .

[5]  J. Pinson,et al.  Fast sweep cyclic voltammetry at ultra-microelectrodes: Evaluation of the method for fast electron-transfer kinetic measurements , 1988 .

[6]  David O. Wipf,et al.  Submicrosecond measurements with cyclic voltammetry , 1988 .

[7]  R. Wightman,et al.  Rapid cleavage reactions of haloaromatic radical anions measured with fast-scan cyclic voltammetry , 1989 .

[8]  R. S. Robinson,et al.  Microsecond spectroelectrochemistry by external reflection from cylindrical microelectrodes , 1982 .

[9]  Alan M. Bond,et al.  Application of transient electrochemical techniques to inlaid ultra-microelectrodes: Assessment of fabrication quality , 1987 .

[10]  A. Bond,et al.  Electrochemistry in organic solvents without supporting electrolyte using platinum microelectrodes , 1984 .

[11]  I. Uchida,et al.  An Electrochemical Fabrication Method for Platinum Ultramicro Disk Electrodes , 1987 .

[12]  J. Savéant,et al.  Fast chemical steps coupled with outer-sphere electron transfers: application of fast scan voltammetry at ultramicroelectrodes to the cleavage of aromatic halide anion radials in the microsecond lifetime range , 1988 .

[13]  Werner G. Kuhr,et al.  Background subtraction for rapid scan voltammetry , 1986 .

[14]  R. M. Wightman,et al.  Microdisk electrodes: Part I. Digital simulation with a conformal map , 1989 .

[15]  H. Baumgärtel,et al.  The influence of cations on the interface between the mercury electrode and non-aqueous CH3CN , 1985 .

[16]  David O. Wipf,et al.  Fast-scan cyclic voltammetry as a method to measure rapid heterogeneous electron-transfer kinetics , 1988 .

[17]  K. Aoki,et al.  Linear sweep voltammetry at very small stationary disk electrodes , 1984 .

[18]  R. Wightman,et al.  Scan rate dependence of the apparent capacitance at microvoltammetric electrodes , 1985 .

[19]  R. S. Robinson,et al.  Absorption spectroelectrochemistry with microelectrodes , 1981 .

[20]  A. Baranski.  Alternating Current Voltammetry with Carbon Fiber Microelectrodes , 1986 .