Facile strategy for the synthesis of silver nanoparticles on magnetic Fe3O4@C core–shell nanocomposites and their application in catalytic reduction

Abstract

The integration of noble metal nanoparticles (NPs) on magnetic hollow structures is of particular importance for high catalytic activity, while the magnetic property is useful for the recovery of the composites. Herein, we prepared Ag NP decorated Fe₃O₄@C hollow magnetic microtubes by a facile and controllable approach. To this end, tannic acid-ferric ion (TA-Fe) first polymerized in situ on the MoO₃@FeOOH microrods and served as a reducing/stabilizing agent to integrate Ag NPs with high coverage. Moreover, no extra reductant was required owing to the reducibility of TA for the formation of FeOOH@TA-Fe/Ag microtubes. After thermal treatment under an N₂ atmosphere, hollow Fe₃O₄@C-Ag microtubes are obtained with a high surface area and excellent magnetism. Remarkable catalytic activity was achieved towards the reduction of 4-nitrophenol (4-NP) owing to the high coverage of Ag NPs on the tube-like structure, while the composite was easily collected with an external magnet. The integration of Ag NPs and the magnetic hollow structure provides a great platform for designing hybrid catalysts with high efficiency and recoverability.