石墨烯复合功能材料及其在重金属离子检测的电化学研究与应用

Research and Application of Graphene Functional Materials Composite and Their Electrochemical in Heavy Metal Ion Detection

石墨烯(GR)是典型的单原子碳纳米材料,具有独特的二维共辄平面结构,其高活性的比表面积和突出的导电性能,在电催化和敏感材料制备领域已得到广泛的应用。氧化石墨烯(GO)作为GR的前驱体,存在大量的含氧官能团,具有良好的水溶分散性。大量GO含氧官能团的介入会破坏其K-7T共辘结构,导致其电学性能变差。GO通过化学、水热合成或直接电化学还原方法可有效修复其共辄平面结构,得到导电性良好的还原氧化石墨烯(rGO),即GR.单组分的GR材料在实际应用中仍存在某些局限性,如电学活性相对较弱,与其它材料加工复合性能较差等。将GR、G O材料与其它功能材料进行复合,可进一步改善复合物的物理或化学性能,如分散性、加工修饰和电催化活性等。综述了石墨烯材料与金属及其氧化物纳米粒子、聚合物、掺杂原子、导电离子液体、碳纳米材料等功能材料复合后,能形成可调控的微结构,具有改性的化学性质和协同发挥的电学效应,表现出显著的电子传递能力及其功能性作用。论述了GR功能化修饰的复合材料作为敏感界面,构筑基于重金属离子检测的电化学生物传感器,可以实现对Pb2+,Hg2+,C『+等多种重金属离子的同时或分别检出,提出了GR复合制备材料的纳米结构特征、功能修饰作用对于提高传感器的电催化活性和选择性性能等方面的应用,并对该研究领域进行了总结与展望。

Graphene(GR) is a typical monatomic carbon nanomaterial with a unique two-dimensional conjugated planar structure and has been widely used in the field of electrocatalysis and sensitive materials due to its high activity of specific surface area and outstanding conductivity. Graphene oxide(GO) as a precursor of GR, possesses a large number of oxygen-containing functionalities, which has a good water-soluble dispersion. However, the intercalation of a large number of oxygen-containing functionalities on GO can destroy its π-π conjugated structure, resulting in poor electrical properties. Chemical, hydrothermally synthesized or directly electrochemical reduction method can effectively restore the conjugated plane structure of GO so as to convert GO to reduced graphene oxide(rGO) with a good conductivity. Nevertheless, one-component GR materials still have some limitations in practical application, such as relatively weak electrical activity and poor performance in processing with other materials. The combination of GR or GO materials with other functional materials can further improve the physical or chemical properties of composites, such as dispersibility, process modification ability and electrocatalytic activity. This paper reviews the synthesis of graphene materials with metal and its oxide nanoparticles, polymers, doped atoms, conductive ionic liquids, carbon nanomaterials and other functional materials for forming a controlled microstructure with modified chemistry nature and synergistic electrical effect, showing a significant electron transfer ability and functional role. We also discussed that GR functionalized composite as a sensitive interface was used for construction of an electrochemical biosensor based on detection of heavy metal ions, which can detect Pb2+, Hg2+ and Cu2+ ions simultaneously or respectively. We put forward the nano-structure features and modifying functions of GR composite materials for important applications, and this research field was also summarized and prospected.