Scalable Fabrication of Carbon Nanomaterials by Electrochemical Dual-Electrode Exfoliation of Graphite in Hydroxide Molten Salt

Abstract

Simultaneous electroexfoliation of graphite on both cathode and anode in molten NaOH–KOH was proposed and found to be a feasible method for the mass production of carbon nanomaterials. During this electrolysis process, alkaline cations and hydroxide ions were intercalated into the bulk graphite and then discharged to generate alkaline metals and hydrogen at the cathode, and oxygen at the anode. The simultaneous intercalation on both electrodes and the escape of gas enhanced the exfoliation efficiency, leading to a high production rate of nanostructured carbon exceeding 26.9 g h–1. The four to seven layers of graphene nanosheets with negligible defect (ID/IG = 0.079) and low oxidation degree (C/O ratio = 20.32) were obtained through cathodic exfoliation, while the corresponding anodic exfoliation products featured more oxygen-containing functional groups (7.59%). This introduced method was beneficial for the mass production of carbon materials in a highly efficient way.