Design and synthesis of tungsten trioxide/polypyrrole/graphene using attapulgite as template for high-performance supercapacitors

Tungsten trioxide/polypyrrole/graphene (WO3/PPy/G) was designed and synthesized by using attapulgite (ATP) as the hard template. The resultant WO3/PPy/G ternary composites were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), cyclic voltammetry and electrochemical impedance spectroscopy (EIS), respectively. The etching and removal of ATP hard template by hydrofluoric acid (HF) result in the porous structure within the WO3/PPy/G, which may improve the electron transfer, shorten the diffusion path of ions, and increase the contact surface between the electrolyte and active material. The existence of PPy and G can enhance the electrical conductivity and mechanical strength of the WO3/PPy/G, respectively, leading to improved pseudocapacitance behaviors of WO3. Moreover, the WO3/PPy/G ternary composites display good rate performance and tolerable cyclic stability when used as supercapacitor electrodes. (C) 2019 Elsevier Ltd. All rights reserved.