A novel strategy to fabricate multifunctional Fe3O4@C@TiO2 yolk–shell structures as magnetically recyclable photocatalysts

Abstract

Using poly(acrylic acid) (PAA) as a template, a novel Fe₃O₄@C@TiO₂ yolk–shell structure derived from heat treatment on Fe₂O₃@PAA@TiO₂ core–shell structures is constructed, where the interior void volume and shell thickness are readily tuned. In this method, the PAA shell between the original spherical α-Fe₂O₃ nanoparticle (NP) core and the outer TiO₂ shell replaces the common SiO₂ template leaving out the tedious treatment procedure of the template. After calcination, the α-Fe₂O₃ core was reduced to the Fe₃O₄ core providing the NPs with magnetic properties and the middle carbon coating around the magnetic core could avoid the occurrence of photodissolution. Moreover, the obtained Fe₃O₄@C@TiO₂ yolk–shell nanocomposites (NCs) exhibit fine photocatalytic activity for the photodegradation of organic contaminants in waste water.