Conductive Boron-Doped Diamond Powder/Nanoparticles for Electrochemical Applications

B-doped diamond is an excellent grinding material owing to its high hardness, oxidation resistance and chemical inertness as well as low resistance. The recent developments of Boron doped conductive diamond has further increased the scale of diamond applications including the manufacture of electrically conductive grinding wheel or the use as an electrode in EDM. The unique electrochemical properties also attract the researchers’ attention on the applications of electrode, sensor and detectors etc. This paper presents a viable technology that high boron doped diamond is synthesized under high pressure and high temperature using B-doped GICs as carbon sources. The synthetic diamond grains with electrically resistivity of 2cm are sufficiently conductive for electrochemistry measurement. Cyclic voltammotry was performed to evaluate the electrode characteristics of diamond powder. The results shows that B-doped diamond powder electrode is electrochemically stable in the supporting electrolytes such as 0.1M KCl, 0.5M Na2SO4 and 0.1M H2SO4 over a wide potential range. The level of background current is very low. The electrode reaction is quasi-reversible in 0.5M Na2SO4 containing the ferricyanide-ferrocyanide redox couple.

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High Pressure High Temperature Synthesis of Highly Boron Doped Diamond Microparticles and Porous Electrodes for Electrochemical Applications

10.26434/chemrxiv.12619697 ◽

2020 ◽

Author(s):

Georgia Wood ◽

Mark Newton ◽

Viacheslav Shkirskiy ◽

Patrick R. Unwin ◽

Julie Macpherson ◽

...

Keyword(s):

High Pressure ◽

High Temperature ◽

Chemical Vapor ◽

Porous Electrodes ◽

Boron Doped Diamond ◽

Voltammetric Analysis ◽

Boron Doped ◽

Electrochemical Applications ◽

High Pressure High Temperature ◽

Aqueous Solvent

High pressure high temperature (HPHT) synthesis of crystallographically well-defined boron doped diamond (BDD) microparticles, suitable for electrochemical applications and using the lowest P and T (5.5 GPa and 1200°C) growth conditions to date, is reported. This is aided through the use of a metal (Fe-Ni) carbide forming catalyst and an aluminum dibromide (AlB2) boron source. The latter also acts as a nitrogen sequester, to reduce boron-nitrogen charge compensation effects. Raman microscopy and electrochemical measurements on individual microparticles reveal they are suitably doped to be considered metallic-like and contain negligible sp2 bonded carbon. A compaction process is used to create macroscopic porous electrodes from the BDD microparticles. Voltammetric analysis of the one-electron reduction of Ru(NH3)63+ reveals large capacitive and resistive components to the current-voltage curves, originating from solution trapped within the porous material. Scanning electrochemical cell microscopy (SECCM) is employed to map the local electrochemical activity and porosity at the micron scale. These electrodes retain the advantageous properties of polycrystalline BDD grown by chemical vapor deposition, such as large aqueous solvent window and resistance to corrosion, but with the additional benefits of a high, electrochemically accessible, surface area.

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High Pressure High Temperature Synthesis of Highly Boron Doped Diamond Microparticles and Porous Electrodes for Electrochemical Applications

10.26434/chemrxiv.12619697.v1 ◽

2020 ◽

Author(s):

Georgia Wood ◽

Mark Newton ◽

Viacheslav Shkirskiy ◽

Patrick R. Unwin ◽

Julie Macpherson ◽

...

Keyword(s):

High Pressure ◽

High Temperature ◽

Chemical Vapor ◽

Porous Electrodes ◽

Boron Doped Diamond ◽

Voltammetric Analysis ◽

Boron Doped ◽

Electrochemical Applications ◽

High Pressure High Temperature ◽

Aqueous Solvent

High pressure high temperature (HPHT) synthesis of crystallographically well-defined boron doped diamond (BDD) microparticles, suitable for electrochemical applications and using the lowest P and T (5.5 GPa and 1200°C) growth conditions to date, is reported. This is aided through the use of a metal (Fe-Ni) carbide forming catalyst and an aluminum dibromide (AlB2) boron source. The latter also acts as a nitrogen sequester, to reduce boron-nitrogen charge compensation effects. Raman microscopy and electrochemical measurements on individual microparticles reveal they are suitably doped to be considered metallic-like and contain negligible sp2 bonded carbon. A compaction process is used to create macroscopic porous electrodes from the BDD microparticles. Voltammetric analysis of the one-electron reduction of Ru(NH3)63+ reveals large capacitive and resistive components to the current-voltage curves, originating from solution trapped within the porous material. Scanning electrochemical cell microscopy (SECCM) is employed to map the local electrochemical activity and porosity at the micron scale. These electrodes retain the advantageous properties of polycrystalline BDD grown by chemical vapor deposition, such as large aqueous solvent window and resistance to corrosion, but with the additional benefits of a high, electrochemically accessible, surface area.

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