Cobalt(II) phthalocyanine-sensitized hollow Fe3O4@SiO2@TiO2 hierarchical nanostructures: Fabrication and enhanced photocatalytic properties

Cobalt(II) phthalocyanine-sensitized hollow Fe3O4@SiO2@TiO2 hierarchical nanostructures had been successfully obtained by combination of solvothermal processing and dipping processing. The as-obtained products were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), UV–vis diffuse reflectance (DR) and vibrating sample magnetometer (VSM). The results revealed that the cobalt(II) phthalocyanine was successfully grown on the primary Fe3O4@SiO2@TiO2 nanostructures (Fe3O4@SiO2@TiO2@CoPcS). The hollow Fe3O4@SiO2@TiO2@CoPcS hierarchical nanostructure showed excellent photocatalytic efficiency for the degradation of methylene blue (MB) under UV–vis and visible light irradiation. More importantly, the photocatalyst could be effectively separated for reuse by simply applying an external magnetic field. A possible mechanism for the visible photocatalysis with the Fe3O4@SiO2@TiO2@CoPcS heterostructures was suggested.