Synthesis of small yolk–shell Fe3O4@TiO2 nanoparticles with controllable thickness as recyclable photocatalysts†
Abstract
Core–shell nanophotocatalysts consisting of superparamagnetic cores and functional shells are intriguing in environmental remediation and biology. A few Fe3O4@TiO2 particles have been developed in previous research studies, while most of them show a submicron-scale size and thick SiO2 interlayers. Herein, we present a facile approach to prepare small Fe3O4@TiO2 with a unique yolk–shell structure below 50 nm, in which most of the SiO2 interlayers have been simultaneously etched off during synthesis. The prepared photocatalysts have been characterized by TEM, XRD, BET and VSM, and a formation mechanism is proposed. Controllable thickness of the TiO2 shell has been achieved and its effect on their photocatalytic activities has also been investigated. These small yolk–shell Fe3O4@SiO2 nanoparticles are expected to be applied in a variety of fields due to their low density, high surface area, superparamagnetic behavior and good photocatalytic activity.