Wanhong Sun

Synthesis of Highly Conductive PPy/Graphene/MnO2 Composite Using Ultrasonic Irradiation

Highly conductive polypyrrole/graphene/manganese dioxide (PPy/graphene/MnO2) composites are fabricated via ultrasonic irradiation using p-toluenesulfonic acid as a dopant. The microstructures of PPy/graphene/MnO2 are evidenced by the SEM and TEM examinations. The effects of the graphene and MnO2 loading on the electrical conductivity are investigated. The maximum conductivity of PPy/graphene/MnO2 composites about 17.15 S/cm found with 3 wt% graphene and 48.7 wt% MnO2 at room temperature. Such uniform structure together with the observed high conductivities afforded high specific capacitance. A specific capacitance of as high as 258 F/g at a current density of 1 A/g was achieved over the PPy/graphene/MnO2 composite.

Facile synthesis of highly conductive PPy/graphene nanosheet /Gd3+ composites

Highly conductive PPy/graphene nanosheet and PPy/graphene nanosheet/Gd3+ composites were prepared via in-situ polymerization with p-toluenesulfonic acid as a dopant and FeCl3 as an oxidant. The effects of graphene nanosheet obtained by two different synthetic methods and Gd3+ on the electrical conductivity of the composites were investigated. The results showed that the graphene nanosheet as a filler had an effect on the conductivity of PPy/graphene nanosheet similar to PPy/graphene nanosheet/Gd3+ composites, which played an important role in forming a conducting network in PPy matrix. Thermal gravimetric analysis demonstrated an improved thermal stability of PPy in the PPy/graphene nanosheet/Gd3+ composites. The microstructures of PPy/graphene nanosheet/Gd3+ were characterized by scanning electron microscope and transmission electron microscope examinations.