Synthesis of chemically modified macroreticular resins for the preparation of gold nanoparticles via sorption from aqueous gold solution, and the application of these nanoparticles in catalytic remediation

Abstract

A new solid-phase support for the preparation of stable gold nanoparticles (AuNPs) was developed, consisting of maleic anhydride and alkyl (C18) vinyl monomer encapsulated into a macroreticular polystyrene resin (Amberlite XAD-2). The maleic anhydride moieties were further modified with either diethylenetriamine (to form the resin RN) or NaOH (to form the resin RCO). The sorption of gold ions from an aqueous gold solution was attempted in a batch process. Gold nanoparticles were immobilized into the pores of both resins by shaking them with aqueous solution containing H[AuCl4] for 1 h at room temperature and then drying them for 24 h at 150 °C to form RN-AuNPs and RCO-AuNPs. The conversion of gold to metallic nanogold was achieved without the use of any external reducing agents. The AuNPs prepared in this manner were characterized by UV–vis spectroscopy and transmission electron microscopy (TEM). The catalytic activity of the prepared nanoparticles in the reduction of 4-nitrophenol was studied, and with the kinetic parameters for this catalyzed reaction were calculated.