In situ preparation of core-satellites nanostructural magnetic-Au NPs composite for catalytic degradation of organic contaminants

Abstract

In this work, core-satellites nanostructural composites have been synthesized through self-assembly combined with in situ growth strategy for catalytic degradation of common organic contaminants. At first, a three-component microsphere catalyst support containing alkyl-functionalized Fe3O4 magnetite core and a layered chitosan (CTS) shell has been constructed for loading of gold nanoparticles (Au NPs). Wherein, the Fe3O4 microsphere core is in favor for recycling and the formation of a hexadecyltrimethoxysilance@CTS (C-16@CTS) layer effectively increases its surface area and provides more docking sites for small Au satellite NPs to construct core-satellites nanostructure. Through electrostatic interaction and coordination, small Au NPs automatically assembled on the surface of support which served as seeds for further in situ growth of bigger stable Au NPs. The obtained catalyst was stable and had enhanced performance for fast catalytic reduction and fading of common organic contaminants, including 4-nitrophenol (4-NP), methylene blue (MB), Congo red (CR), rhodamine B (RhB), rhodamine 6G (R6G), acid orange (AO) and methyl orange (MO). No significant inactivation of the catalyst was observed even after recycling for eleven cycles or stored for more than 1 month. In addition, the catalyst was used for effective degradation of organic pollutant in Yellow River water sample, which indicated its potential for practical applications in water pollutant removal and environmental remediation. (C) 2014 Elsevier B.V. All rights reserved.