Electroless oxidation of boron-doped diamond surfaces: comparison between four oxidizing agents; Ce, MnO4, H2O2 and S2O8

The electrochemical properties of diamond are very sensitive to the surface terminations. It is still a challenge to successfully produce well-defined “C-O” functions. In this paper, we describe and compare the oxidation of as-grown polycrystalline boron-doped diamond (BDD) films using four different oxidizing agents in aqueous media: Ce⁴⁺, MnO₄⁻, H₂O₂ and S₂O₈²⁻. The different treatments lead to the formation of oxygenated functions at the diamond surface, mainly singly oxidized “C-O” groups such as “C-OH” or “C-O-C”. Processes with Ce⁴⁺ and MnO₄⁻ seem to be particularly interesting as they both lead to the creation of a high amount of oxygenated functions and an improvement of the charge transfer at BDD surfaces.