Impact of mesoporous SiO support for Ni/polypyrrole nanocomposite particles on their capacitive performance

Electro-conducting polypyrrole (PPy) coated H 2 N-SiO 2 /Ni nanocomposite particles are prepared by a three-step process. The objective is to analyze the influence of porous functional SiO 2 support on the electrochemical performance of the prepared H 2 N-SiO 2 /Ni/PPy nanocomposite particles. H 2 N-SiO 2 support is first prepared by a modified solgel method and then co-ordinated with Ni nanoparticles via an amine functionality. Finally, H 2 N-SiO 2 /Ni/PPy nanocomposite particles are prepared by in situ chemical oxidative polymerization of pyrrole using citric acid as a dopant. Fourier Transform IR (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the formation of co-ordinated Ni/Ni 2+ nanoparticles and a PPy layer with almost a coreshell type morphology. The mesoporous surface structure of H 2 N-SiO 2 core-particles is confirmed from the morphological study and the specific surface area gradually decreased from 496 m 2 g 1 to 59 m 2 g 1 following subsequent surface modification with Ni nanoparticles and the PPy layer. The ultimate nanocomposite particles had paramagnetic properties and the magnetization value is 4.8 emu g 1 . Comparative electrochemical performance between electrodes made from the respective PPy, Ni/PPy and H 2 N-SiO 2 /Ni/PPy showed the highest specific capacitance value (982.6 F g 1 from cyclic voltammetry curves) for the H 2 N-SiO 2 /Ni/PPy nanocomposite. The H 2 N-SiO 2 /Ni/PPy nanocomposite electrode is fairly stable during cycling measurement. The results indicated that the use of mesoporous functional SiO 2 support remarkably improved the mechanical stability and capacitive performance of the H 2 N-SiO 2 /Ni/PPy nanocomposite electrode, suitable for application in energy storage devices. The inclusion of mesoporous H 2 N-SiO 2 support in H 2 N-SiO 2 /Ni/PPy nanocomposite particles improved their electrochemical performance, suitable for energy storage devices.