Characterization of Sol-Gel Derived Composite Silica Carbon Electrodes

Abstract

Sol-gel derived composite silica-carbon electrodes exhibit favorable electrochemical characteristics. The electrodes benefit from the conductivity and electrochemical advantages of the carbon powder, from the favorable properties of the ceramic network and from the versatility of the sol-gel process. Hydrophobie composite electrodes reject water, only their outermost surface is wetted and they exhibit good signal to background currents. A comparison of several types of carbon powders reveals that higher carbon loading and larger surface area electrodes can be attained by incorporation of dense graphite powder. When high surface area, small size carbon-black powder is used, a homogeneous distribution of microelectrodes, separated by insulating modified silica is formed. This ensemble of microelectrodes increases the sensitivity of the CCEs by more than two orders of magnitude as compared to glassy carbon electrode and graphite CCEs.