Electrochemical behavior of boron-doped diamond electrodes

Boron-doped diamond electrodes have many possibilities for electroanalytical and electrosynthetic application because of their stability and range. However, their combination of semiconductive origin, nearly metallic resistive characteristics when heavily doped, and surface inertness make the understanding of electron transfer at these materials complex. The transition from reversible behavior, with a wide range of outer sphere redox couples with potentials positive of about -0.5 V vs. SCE, to extremely slow kinetics, with systems such as the halogen/halide couples, requires placing all the above properties in context. Experimental data pertaining to these issues and speculation concerning the controlling factors are discussed.