Fabrication and characterization of core-shell polystyrene/polyaniline/Au composites and their catalytic properties for the reduction of 4-nitrophenol

Herein, polystyrene/polyaniline/Au (PS/PANI/Au) composites were prepared by a novel method using self-made Au(en)(2)Cl-3 as the Au source and were used as the catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Before the preparation of PS/PANI/Au, PS microparticles were sulfonated by the copolymerization between styrene and sodium 4-styrenesulfonate (SSS). Then self-made Au(en)(2)Cl-3 was added and Au(en)(2)(3+) species were adsorbed on the surface of sulfonated PS particles due to the electrostatic attraction. The Au(en)(2)(3+) was then reduced to Au nanoparticles in situ by aniline monomer. After the polymerization of the residual aniline monomer by ammonium persulfate (APS), the PS/PANI/Au composite catalysts were obtained. The morphology and structure of the as prepared PS/PANI/Au composites were characterized by TEM, FT-IR, XPS and EDX. Their catalytic performance for the reduction of 4-NP by NaBH4 was evaluated by means of UV-vis spectroscopy. The as prepared PS/PANI/Au composites are very active for the reduction of 4-NP by virtue of the interaction between Au nanoparticles and PANI shell. The catalytic reaction obeys the pseudo-first-order reaction equations and the reaction rate constants are also calculated in this paper. (C) 2016 Elsevier B.V. All rights reserved.