MoS_2/石墨烯复合材料的制备及其电化学性能

Synthesis and electrochemical performance of MoS_2/graphene composite

采用水热法以钼酸铵、氧化石墨烯和硫脲作为原料制备得到不同石墨烯含量的MoS_2/石墨烯复合材料。利用XRD、Raman、SEM、TEM和电化学测试对复合材料的形貌、结构和电化学性能进行了表征。结果表明,氧化石墨烯和钼酸根离子被成功地还原成MoS_2/石墨烯复合材料,同时MoS_2纳米片均匀地分散在石墨烯表面上。当氧化石墨烯为800mg时复合材料的电化学性能最佳,在电流密度为1A/g时,比容量高达310F/g,经过500次循环后比容量仍保持在230F/g。以上研究结果说明,石墨烯片层的介入有效地阻碍了MoS_2纳米片的堆叠,提高复合材料的比容量和循环稳定性。

MoS 2/graphene composites with different content of graphene were prepared by a hydrothermal method using ammonium molybdate,graphite oxide(GO)and thiourea as raw materials.The morphology and structure of the obtained materials were examined by X-ray diffraction,Raman spectroscopy,scanning electron Microscopy and transition electron microscopy.Electrochemical properties were evaluated by cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopy.The results indicate that GO and Mo 2O 7 2-in reaction solution have been reduced to MoS 2/graphene composites.The obtained MoS 2 nanoflakes are deposited on the surface of graphene.The composite containing 800 mg GO exhibited the best performance,which showed the specific capacitance of 310 F/g at a current density of 1 A/g and it remained 230 F/g after 500 cycles.The results indicate that the intercalation of graphene prevents the aggregation of MoS 2 nanoflakes effectively,resulting in large specific surface area.The capacity and stability of the composites are greatly increased by the addition of graphene.