Fundamentals of Diamond Electrochemistry

This tutorial is devoted to diamond, as an electrode material, for its application in electrochemistry. A short introduction on synthetic diamond history is presented to contextualize the development of diamond science, together with its synthesis by chemical vapor deposition. Although this review is mostly devoted to boron-doped diamond, it encompasses different doping elements (nitrogen, phosphorus, and sulfur). Physical characterizations (Raman, XPS, secondary ion mass spectrometry, and glow discharge optical emission spectroscopy) are introduced, which are fundamental to describe the diamond features and their correlation with the electrochemical response. The fundamental electrochemical properties of diamond are reviewed in detail, including electron transfer processes and generation of reactive radical species, notably the hydroxyl radical. Finally, electrochemical applications (e.g., CO2 and NO3– reduction, SO42– and CO32– oxidation, wastewater treatment, organic electrosynthesis, and electroanalysis) are generally discussed, introducing relevant examples.