This study aims to investigate a novel technique to improve the yield of liquid phase exfoliation of graphite to graphene sheets. The method is based on the utilization of magnetic Fe₃O₄ nanoparticles as “particle wedge” to facilitate delamination of graphitic layers. Strong shear forces resulted from the collision of Fe₃O₄ particles with graphite particles, and intense ultrasonic waves lead to enhanced exfoliation of graphite. High quality of graphene sheets along with the ease of Fe₃O₄ particle separation from graphene solution which arises from the magnetic nature of Fe₃O₄ nanoparticles are the unique features of this approach. Initial graphite flakes and produced graphene sheets were characterized by various methods including field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Zeta potential analysis. Moreover, the effect of process factors comprising initial graphite concentration, Fe₃O₄ nanoparticles concentration, sonication time, and sonication power were investigated. Results revealed that graphene preparation yield and the number of layers could be manipulated by the presence of magnetic nanoparticles.

这项研究旨在研究一种新技术，以提高液相剥离石墨到石墨烯片的产率。该方法基于利用磁性Fe ₃ O ₄纳米颗粒作为“颗粒楔”来促进石墨层的分层。Fe ₃ O ₄颗粒与石墨颗粒的碰撞产生了很强的剪切力，而强烈的超声波导致石墨的剥落增强。高质量的石墨烯片以及易于从石墨烯溶液中分离出Fe ₃ O _4的颗粒，这归因于Fe ₃ O ₄的磁性纳米颗粒是这种方法的独特功能。通过多种方法对初始石墨薄片和生产的石墨烯片进行了表征，包括场发射扫描电子显微镜（FE-SEM），透射电子显微镜（TEM），拉曼光谱，原子力显微镜（AFM），傅立叶变换红外光谱（FTIR），X射线衍射（XRD）和Zeta电位分析。此外，研究了工艺因素对初始石墨浓度，Fe ₃ O ₄纳米粒子浓度，超声处理时间和超声处理能力的影响。结果表明，石墨烯的制备产率和层数可以通过磁性纳米粒子的存在来控制。