Polypyrrole single and double-shelled nanospheres templated by pyrrole–Hg(II) complex: Synthesis, characterization, formation mechanism and electrochemical performance

Spherical and yolk/shell nanostructures of pyrrole (Py)–Hg(II) complex have been formed by mixing Py monomer with HgCl2 in aqueous solution as white precipitation. Templated by spherical and yolk/shell nanostructures of Py–Hg(II) complex, polypyrrole (PPy) single and double-shelled hollow nanospheres have been successfully fabricated by simply introducing an oxidant to initial the polymerization of Py monomer on the surface of templates. Formation mechanisms of PPy nanostructures involved have been discussed in detail according to experimental observations. When hollow PPy spheres were used as the electrode materials for the supercapacitors, the specific capacity can achieve 252 F g−1 at the current density of 0.5 A g−1. Results indicated that the material has good cyclic stability, and is suitable to be applied as a good supercapacitor material.