Fabrication of graphene from graphite using high-powered ultrasonic vibrators

Abstract

This paper utilizes an efficient and environmentally friendly method for synthesizing graphene from graphite, namely liquid-phase exfoliation. High-power density ultrasonic vibrators were used to separate graphite layers into graphene in a liquid medium. During layer separation, ultrasonic waves provided mechanical energy to break the Van der Walls bonds and separate graphite layers into graphene. In our study, graphene was synthesized by ultrasonicating graphite in Tween 80 for 1 to 5 h, followed by magnetic stirring and surfactant removal. The FESEM and Raman measurements demonstrated that high-frequency ultrasound waves were effective at breaking the Van der Waals bonding force between adjacent graphite layers. Average flake sizes (lateral) were reduced with increasing ultrasonication time, reaching a minimum value of 317 nm with 5 h of ultrasonic treatment. These results show that liquid-phase exfoliation is a cost-effective method to obtain low-defect few-layer graphene.

Keywords

• graphene
• graphite
• high-power density
• ultrasonication
• surfactant