Carbon, and particularly graphite in its various forms, is an attractive electrode material. Two areas of particular interest are modified carbon electrodes and carbon nanotube electrodes. In this article we focus on the relationship between surface structure and electrochemical and chemical reactivity of electrodes based on these materials. We overview recent work in this area which has led us to believe that much of the catalytic activity, electron transfer and chemical reactivity of graphitic carbon electrodes is at surface defect sites, and in particular edge-plane-like defect sites. We also question the claimed special “catalytic” properties of carbon nanotube modified electrodes.

The application of electrochemical impedance spectroscopy (EIS) has increased dramatically in the past few years due to its ability to elucidate a plethora of physical and electronic properties of electrochemical systems such as diffusion coefficients, electron transfer rate constants, adsorption mechanisms, charge transfer resistances, capacitances and pore sizes. This review provides a short introduction to the fundamental principles of EIS before exploring the many exciting and pertinent analytical applications regarding the numerous methods in biosensing, the application of EIS with graphene based materials and last, the use of EIS with screen printed electrodes.