Polymer brush-assisted preparation of magnetic Au nanocatalyst for highly efficient reduction of organic pollutants

In this work, magnetic nanoparticles (Fe 3 O 4 ) immobilized with poly(4-vinylpyridine) (P4VP) brushes were prepared by Cu(0)-reversible deactivation radical polymerization (Cu(0)-RDRP) for the coordination of Au 3+ , which subsequently yielded Au nanoparticles by Fe 3 O 4 and ethanol reduction system to realize a green synthesis without using toxic chemicals. Morphology observation shows that Fe 3 O 4 @P4VP-Au nanocatalyst is distributed uniformly without significant agglomeration. Au nanoparticles with an average diameter of 2.71 nm are firmly anchored on the surface of Fe 3 O 4 @P4VP-Au by using P4VP brushes as a skeleton to support. The hybrid Fe 3 O 4 @P4VP-Au nanocatalyst demonstrates superior properties such as high structure stability, small size and uniform Au nanoparticles distribution, convenient reuse recovery, and good biocompatibility. It also has remarkable catalytic activity for nitrophenols and methylene blue. The catalytic activity can still keep above 98.5% even after ten cycles. This study presents a green and simple route for Au-nanocatalyst synthesis, which provides fresh insights and useful implications for designing efficient and sustainable Au nanocatalysts. • Poly(4-vinylpyridine) brushes were prepared by Cu(0)-RDRP for the coordination and stabilization of Au 3+ . • Au nanoparticles are achieved by Fe 3 O 4 and ethanol reduction system without using harmful reagents. • Fe 3 O 4 @P4VP-Au displayed remarkable activity in the catalytic reduction of nitrophenols and methylene blue. • Fe 3 O 4 @P4VP-Au still retained satisfactory stability and activity after 7 cycles.