Anode coverage for enhanced electrochemical oxidation: a green and efficient strategy towards water-dispersible graphene

Abstract

The synthesis of water-dispersible graphene (W-Gr) is essential for both laboratory-scale studies and practical applications. Herein, we report a green electrochemical route followed by post-sonication to prepare few-layered W-Gr of 1–6 atomic layers in thickness and 1.0–7.0 μm² in area with a remarkably high yield (87.3%). Both outstanding dispersibility (8.2 mg mL⁻¹) and good stability (at least 6 months) are achieved in water. Mechanism analysis indicates the critical effect of terephthalic acid coverage on the anode for adequate electrochemical oxidation, which is the prerequisite for subsequent bubble- and sonication-exfoliation. This partial anode coverage strategy provides a new possibility of a simple electrochemical setup to greenly and scalably fabricate graphene with specific functionality.