In situ polymerization and reduction to fabricate gold nanoparticle-incorporated polyaniline as supercapacitor electrode materials

Nanocomposites of gold nanoparticles and polyaniline are synthesized by using HAuCl4 and ammonium peroxydisulfate as the co-oxidant involving in situ polymerization of aniline and in situ reduction of HAuCl4. Through these in situ methods, the synthesized Au nanoparticles of ca. 20nm embedded tightly and dispersed uniformly in polyaniline backbone. With the Au content in composite increasing from 4.20 to 24.72wt.%, the specific capacitance of the materials first increased from 334 to 392Fg(-1) and then decreased to 298Fg(-1). Based on the real content of PANI in composite material, the highest specific capacitance is calculated to be 485Fg(-1) at the Au amount of 19.15wt.%, which remains 55.6% after 5000cycles at the current density of 2Ag(-1). Finally, the asymmetric supercapacitor of AuNP/PANI||AC and the symmetric supercapacitor of AuNP/PANI||AuNP/PANI are assembled. The asymmetric supercapacitor device shows a better electrochemical performance, which delivers the maximum energy density of 7.71Whkg(-1) with power density of 125Wkg(-1) and maximum power density of 2500Wkg(-1) with the energy density of 5.35Whkg(-1).