石墨烯纳米片/CoS2复合材料的制备及其在超级电容器中的应用

采用一步水热法制备石墨烯纳米片（GNS）/CoS₂复合材料，利用XRD和SEM对所制备复合材料的微观结构进行表征，采用循环伏安法和交流阻抗法对复合材料的电化学性能进行研究。研究结果表明，在水热过程中，氧化石墨（GO）逐渐被还原成石墨烯纳米片（GNS），能够为CoS₂晶核的形成提供更多的接触点，有利于CoS₂颗粒均匀地生长在GNS表面。这种结构的复合材料既能够显著增加CoS₂和电解液之间的有效接触面积，提高CoS₂的电化学利用率，同时又能够改善材料的导电性，有利于提高材料的比电容。

Preparation of graphene nanosheet/CoS2 composite and its application in supercapacitors

The graphene nanosheet(GNS)/CoS₂ composite was prepared by the one-step hydrothermal method. The crystal structure and morphology were characterized by XRD and SEM. Electrochemical properties were determined by cyclic voltammetry and electrochemical impedance spectroscopy. Graphite oxide (GO) was gradually reduced to form graphene nanasheet during the hydrothermal process, which could provide abundant contact sites for the formation of CoS₂ crystal nucleus, thus leading to uniform distribution of CoS₂ particles on the surface of graphene. Such novel structure composite not only significantly enhanced the effective contact area between CoS₂ and electrolyte, but also improved electrochemical utilization of CoS₂ electrode materials. Meanwhile, it facilitated electrical conductivity of the material, resulting in increased specific capacitance.