目的 探究和比较制备石墨烯的两种常见方法，即氧化还原法和液相剥离法。方法 采用液相剥离法，在N-甲基吡咯烷酮中超声剥离膨胀石墨制备单层和多层石墨烯，与氧化还原法制备得到的石墨烯在微观形貌和结构表征方面进行比较，并在此基础上比较不同有机溶剂液相剥离制备的石墨烯分散液的浓度和稳定性。结果 液相剥离法得到的石墨烯具有更好的片层结构，分子结构含有较少的杂团和含氧基团，石墨烯片层间距较宽，热稳定性更好。在N-甲基吡咯烷酮中液相剥离制备的石墨烯质量浓度可达0.15 mg/mL，稳定性相对较好，该方法在一系列应用中也更易制备导电薄膜和复合材料。结论 相较氧化还原法，液相剥离法制备的石墨烯性能更好。

The work aims to explore and compare the two commonly used methods to prepare graphene, namely the methods of oxidation-reduction and liquid-phase exfoliation. The liquid-phase exfoliation method was used for the ultrasonic exfoliation of the expanded graphene to prepare single-layer and multi-layer graphenes in N-methyl-2-pyrrolidone and to compare the microstructure and structural characterization of the graphenes prepared in the method of oxidation-reduction. Based on that, the concentration and stability of grapheme dispersion liquid prepared with different organic solvents in the method of liquid-phase exfoliation were compared. The graphene prepared in the method of liquid-phase exfoliation had better lamellar structure and the molecular structure contained less miscellaneous groups and oxygen-containing groups. The lamellar spacing of graphenes was quite wide and the thermal stability was better. The mass concentration of graphene prepared in N-methyl-2-pyrrolidone by means of liquid-phase exfoliation could reach up to 0.15 mg/mL and the stability was relatively good. In a series of applications of such method, it was easier to prepare electro-conductive films and composites. Compared to the method of oxidation-reduction, the graphene prepared in the method of liquid-phase exfoliation has better performances.