Sintering of a nanodiamond in the presence of cobalt

High pressure high temperature synthesis of highly boron doped diamond microparticles and porous electrodes for electrochemical applications

“…To date, there has been relatively little research on the HPHT synthesis of BDD particles 13,[16][17][18][19][20][21][22] Furthermore, of the limited studies undertaken, use of HPHT BDD as an appropriately doped electrochemical material is yet to be demonstrated. In some cases, the boron content is not quantified, 13,19 complete experimental conditions are not reported, 16,17 or the boron content is insufficient for electrochemical use.…”

“…The material was, however, in the form of polycrystalline aggregates in which inhomogeneous boron doping was reported. 20 BDD has also been obtained from a Ni-Mn (catalyst) B-C system, at 5 GPa and 1500-1600 °C, with a boron content of (2±1) ×10 20 cm -3 . 22 The particles produced at this doping level were found to have very rough surfaces with a layer-like structure, lacking well-defined crystal faces.…”

“…In this study, we determine HPHT experimental conditions which result in the synthesis of: (i) well-defined (in terms of crystallographic morphology) BDD microparticles, with (ii) sufficiently high, uncompensated, boron levels so that the material is suitable for use as an electrode, and (iii) use of the lowest P and T conditions to-date. 13,[16][17][18][19][20][21][22] We assess the material and electrochemical properties at both the single particle level and in compacted-particle, porous electrode form. To investigate porosity effects in greater detail we employ scanning electrochemical cell microscopy (SECCM).…”