Synthesis and characterization of nanocrystalline diamond from graphite flakes via a cavitation-promoted process

Basma H Al-Tamimi,Iman I Jabbar,Haitham M Al-Tamimi

doi:10.1016/j.heliyon.2019.e01682

Abstract

Herein, we describe the multi-step synthesis and characterization of monodisperse cubic-structured nanocrystalline diamond particles, showing that they can be easily prepared from graphite flakes under ambient conditions. The above synthesis features the conversion of graphite flakes into graphene oxide (via a modified Hummer's method) and its subsequent transformation into nanodiamond under the action of ultrasonication-induced cavitation, with the nucleation and growth of nanodiamond particles being strongly influenced by the incorporation of a specific metal oxide spacer material. Overall, the developed method is demonstrated to be superior to conventionally used ones, exhibiting the advantages of simplicity, high yield, and upscaling potential.

Highlights

Carbon, one of the most interesting and nature-abundant elements, can exist in the form of several allotropes that differ in the arrangement of carbon atoms within their unit cells [1, 2] and exhibit remarkably variable properties
The recent breakthroughs in the fields of nanoscience and nanotechnology [2, 3] allow the synthesis of nanostructured carbon materials that possessing unique physical and mechanical properties and used in the most critical applications of supramolecular chemistry, mechanical and molecular device fabrication, and mesososcopic physics [2, 4]
Single-crystal ND particles can be produced by high pressure-high temperature synthesis, the use of elevated temperatures (˃2000 K) and pressures (~10000 atm) together with low yields hinders the practical application of this method and necessitates the search for suitable alternatives

Summary

Introduction

One of the most interesting and nature-abundant elements, can exist in the form of several allotropes (diamond, graphite, fullerene, carbon nanotubes, graphene, etc.) that differ in the arrangement of carbon atoms within their unit cells [1, 2] and exhibit remarkably variable properties. The recent breakthroughs in the fields of nanoscience and nanotechnology [2, 3] allow the synthesis of nanostructured carbon materials that possessing unique physical and mechanical properties and used in the most critical applications of supramolecular chemistry, mechanical and molecular device fabrication, and mesososcopic physics [2, 4]. ND is compatible with the human organism and can be functionalized with different biomolecules, being suitable for use as a reinforcing material to produce attractive composites for industrial applications. Compared to other nanocarbon particles, ND ones exhibit unique structural features, e.g., they contain a π-electron network and abundant surface functional groups that allow for surface reconstruction [4]. Single-crystal ND particles can be produced by high pressure-high temperature synthesis, the use of elevated temperatures (˃2000 K) and pressures (~10000 atm) together with low yields hinders the practical application of this method and necessitates the search for suitable alternatives. ND can be efficiently prepared by chemical vapor deposition and detonation techniques, which, are not suitable for scalable production [6, 7]

Methods

Results

Conclusion