Rapid Formation of Diamond-Like Nano-Carbons in a Gas Bubble Discharge in Liquid Ethanol

Abstract

This work demonstrates that diamond-like nano-carbons can be rapidly grown at atmospheric pressure and near ambient temperature in Ar gas bubble discharge in liquid ethanol. The method uses a discharge between point-to-plate electrodes immersed in ethanol, with plasma being generated inside Ar gas bubbles introduced through the needle electrode. The ethanol was dissociated at the liquid/gas interface into reactive species such as C2 and CH, which are the primary species responsible for diamond formation. A mixture of lonsdaleite nano-diamonds, amorphous carbon nano-spheres, and a graphitic carbon network, was formed. The rapid bubble movement distributes the reaction products almost immediately into the liquid phase, ensuring that nucleation of new material continues throughout the process. This simple, inexpensive and fast process avoids the elevated temperatures and extreme pressures of current methods.