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The electrochemical behavior and analytical performance of new vitreous carbon aerogel composite electrodes are described. These new composite electrodes rely on the unique open-cell nanostructure of aerogel materials, including their interconnected porosity, ultrafine pore sizes (<50 nm), and huge surface area. Transmission and scanning electron microscopies are used to shed useful insights into the carbon network. The enhanced diffusional flux results in a sigmoidal voltammetric response and nonlinear i vs tl/2 chronoamperometric plots. The potential window is broad, and the background currents are low.Square-wave anodic stripping voltammetry at the mercury-coated carbon aerogel composite electrode is demonstrated for the quantitation of trace metals at the microgram per liter level using short deposition periods. These carbon aerogels and other aerogels present new opportunities for a wide range of electrode materials.

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Uranyl, UO(2)(2+), was electrochemically determined by a phosphate based self-assembled monolayer. A pretreated gold electrode with 2-mercatpoethanol was chemically modified by POCl(3) or POBr(3) to obtain the surface phosphate active sites. The different stages were characterized by reflection-absorption Fourier transform-infrared (FT-IR) spectroscopy, capacity, and X-ray photoelectron spectroscopy (XPS). The electrochemical determination of UO(2)(2+) was accomplished, after preconcentration under open circuit potential, by square wave voltammetry.

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