In this work, we implement a dual frequency (24 kHz and 1174 kHz) ultrasonic assisted liquid phase exfoliation (ULPE) technique in deionized water (DIW) and other eco-friendly solvents, to produce a variety of high-quality few-layer graphene (FLG) solutions under controlled ultrasonication conditions. The resulting FLG dispersions of variable sizes (∼0.2–1.5 μm) confirmed by characterisation techniques comprising UV–Vis spectroscopy, Raman spectroscopy and high-resolution transmission electron microscopy (HR-TEM). For the first time we demonstrate that high yield of FLG flakes with minimal defects, stable for 6 + months in a solution (stability ∼ 70 %), can be obtained in less than 1-hour of treatment in either water/ethanol (DIW:EtOH) or water/isopropyl alcohol (DIW:IPA) eco-friendly mixtures.

中文翻译：

---

双频超声液相剥离法在绿色溶剂中制备少层石墨烯


在这项工作中，我们在去离子水（DIW）和其他环保溶剂中实施双频（24kHz和1174kHz）超声波辅助液相剥离（ULPE）技术，以生产各种高质量的少层石墨烯(FLG) 受控超声条件下的溶液。通过包括紫外可见光谱、拉曼光谱和高分辨率透射电子显微镜 (HR-TEM) 在内的表征技术证实了所得的不同尺寸 (~0.2–1.5 μm) 的 FLG 分散体。我们首次证明，在水/乙醇（DIW：DIW： EtOH）或水/异丙醇（DIW:IPA）环保混合物。