Enhanced electrochemical performance via PPy encapsulated 3D flower-like bismuth molybdate nanoplates for high-performance supercapacitors

摘要

Novel three-dimensional (3D) flower-like Bi2MoO6 (BMO) nanoplates were successfully synthesized by a hydrothermal method using ethylenediaminetetraacetic acid (EDTA) as a capping agent. The growth mechanism of the 3D flower-like BMO nanoplates was investigated by varying the amount of EDTA during the reaction. The electrochemically conductive BMO/polypyrrole (PPy) hybrid composite was further prepared by in-situ oxidative polymerization method by adding the pyrrole monomer into the aqueous solution of pristine BMO. The X-ray diffraction patterns of the PPy polymer did not show any change on the phase form of the pristine BMO. The electrochemical properties of the PPy coated BMO hybrid composite electrode as well as the prepared 3D flowerlike BMO nanoplate electrode were evaluated in 1 M KOH electrolyte solution. The specific capacitance of the BMO/PPy hybrid composite electrode exhibited the higher specific capacitance value (1253 F g(-1)), which is much higher than the pristine 3D flower-like BMO nanoplate electrode (725 F g(-1)) at a current density of 1 A g(-1). Furthermore, the BMO/PPy hybrid composite electrode maintained 70.4% of capacitance retention after 2000 cycles with respect to the initial specific capacitance value at a higher current density (15 A g(-1)), which indicates that the electrode material has good cycling stability.