Role of sp3/sp2 ratio on the electrocatalytic properties of boron-doped diamond electrodes: A mini review

•Diamond-electrocatalytic properties are strongly influenced by sp3/sp2 ratio.•High sp3/sp2 ratio is suitable in disinfection water, avoiding hazardous species.•BDD with high graphite content could be considered a good electrocatalyst for o.e.r.•High diamond content favors electrochemical combustion to CO2.•sp2-impurity affects background current, potential window, and molecular adsorption.

Recent investigations have confirmed that the sp3 (diamond)/sp2 (graphite) ratio has a key role in the electrochemical properties of boron-doped diamond electrodes. The sp2-carbon impurities affect the voltammetric background current, potential window and molecular adsorption, influencing the electron-transfer kinetics. This parameter also affects the non-active nature of BDD, promoting important variations on the degradation pathway followed during electro-oxidation of organic compounds as well as production of oxidants. These effects are critically discussed and evaluated, providing an up-to-date mini-review.