Designing magnetic catalysts based on gold nanoparticles supported by ethylenediamine tetraacetic acid functionalized amino‐modified poly(N‐isopropyl acrylamide) for reduction of nitro compounds in water

Abstract

A novel smart catalyst was developed with amino‐modified thermo‐responsive poly (N‐isopropyl acrylamide) (PNIPAM) grafts on silica‐coated MNPs using the conventional free radical polymerization process. By this methodology, the polymer was successfully grafted mainly onto the silica modified iron oxide nanoparticles (Fe3O4@Si). The PNIPAM‐grafted Fe3O4@Si was then subjected to ethylenediamine treatment to produce the amino‐functionalized support (Fe3O4@Si@PNIPAM‐NH2), which was subsequently modified with carboxyl functional groups by using EDTA (ethylenediaminetetraacetic acid) to create Fe3O4@Si@PNIPAM‐NH2‐EDTA. Au nanoparticles were then decorated on this support through its two amines and four carboxylates Different methods were used to study this novel catalyst, including ICP, FT‐IR, TGA, DLS, SEM, EDX, VSM, XRD, and CHN. The reduction of several aryl‐nitro derivatives demonstrated a significant catalytic activity for the as‐synthesized gold catalyst (Fe3O4@Si‐PNIPAM‐NH2‐EDTA‐Au). The Au catalyst can be successfully removed from the reaction components using magnetic fields and used again in 8 successive reduction reactions without significant gold leaching and loss of catalytic activity.This article is protected by copyright. All rights reserved.