Channel Flow Cell For UV/Visible Spectroelectrochemistry

A channel-type spectroelectrochemical cell has been designed and constructed for conducting in situ transmission UV/visible spectroscopic measurements of solution phase electrogenerated species. Excellent agreement between theory and experiment was obtained using the oxidation of ferrocyanide in aqueous electrolytes as a probe system. In particular, plots of the (relative) absorbance of the solution at 420 nm (the absorption maximum of ferricyanide in the visible region) measured along the axis normal to the fluid flow downstream from the electrode edge, versus V^−1/3, where V is the flow rate, yielded a straight line with a close to zero intercept Furthermore, a linear relationship was also found between the diffusion-limited current and V^1/3, as expected on the basis of hydrodynamic and electrochemical considerations.