MnO_x/rGO复合材料的水热合成及电容性能

以氧化石墨(GO)为载体,KMnO_4为Mn源,水合肼为还原剂,采用水热法一步合成MnO_x/rGO复合材料,探索KMnO_4与GO质量配比(w)对复合材料结构和电容性能的影响。实验结果表明,w对MnO_x/rGO复合材料的组成和形貌影响显著,当w为1∶3时复合材料主要由大量的Mn_3O_4和rGO(还原氧化石墨)组成,同时含有少量Mn OOH杂相,当w增大至1∶1时新出现少量MnCO_3杂相。随着w增大,rGO表面的MnO_x负载量逐渐增多,颗粒也逐渐长大变粗。MnO_x与rGO两者复合兼具了良好的导电性和高的电容量,当w为1∶1时,MnO_x/rGO复合材料在电流密度为0.05 m A/cm~2条件下的电容量为257 F/g,经过500次循环后容量保持达90.7%。

Hydrothermal Synthesis of MnOx/rGO Composite and Electrochemical Capacitance Properties as Supercapacitor Electrode

MnOx/rGO composites were fabricated by hydrothermal method using graphite oxide (GO), KMnO4 and hydrazine hydrate as raw material. The influence of the mass ratio of KMnO4 to GO (w) on structures and capacitance properties of MnOx/rGO composites were characterized. The experimental results show that thew value has a great effect on the compose and morphology of MnOx/rGO composites. The MnOx/rGO composites with thew value 1:3 consist of minor amount Mn3O4 and rGO and a little amount of MnOOH. With thew value increasing to 1:1, a little amount of MnCO3 is also formed. The load amount of MnOx on rGO surface increases gradually and the particles of MnOx became thicker with thew value increasing. The combination of MnOx and rGO could improve the conductivity and capacitance. The capacitance of the MnOx/rGO composite with thew value 1:1 is 257 F/g at a current density of 0.05 mA/cm2 and the capacity retention is 90.7% after 500 cycles.