Synthesis of double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres and their catalytic applications

Nanotechnology. 2015 Mar 6;26(9):095601. doi: 10.1088/0957-4484/26/9/095601. Epub 2015 Feb 10.

Abstract

Double-shelled sea urchin-like yolk-shell Fe3O4/TiO2/Au microspheres were successfully synthesized through loading Au nanoparticles on the Fe3O4/TiO2 support by a in situ reduction of HAuCl4 with NaBH4 aqueous solution. These microspheres possess tunable cavity size, adjustable shell layers, high structural stability and large specific surface area. The Au nanoparticles of approximately 5 nm in diameter were loaded both on the TiO2 nanofibers and inside the cavities of sea urchin-like yolk-shell Fe3O4/TiO2 microspheres. The sea urchin-like structure composed of TiO2 nanofibers ensure the good distribution of the Au nanoparticles, while the novel double-shelled yolk-shell structure guarantees the high stability of the Au nanoparticles. Furthermore, the Fe3O4 magnetic core facilitates the convenient recovery of the catalyst by applying an external magnetic field. The Fe3O4/TiO2/Au microspheres display excellent activities and recycling properties in the catalytic reduction of 4-nitrophenol (4-NP): the rate constant is 1.84 min(-1) and turnover frequency is 5457 h(-1).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Gold / chemistry
  • Magnetite Nanoparticles / chemistry*
  • Magnetite Nanoparticles / ultrastructure
  • Microspheres*
  • Titanium / chemistry

Substances

  • Magnetite Nanoparticles
  • titanium dioxide
  • Gold
  • Titanium