Sensitization of magnetite@SiO2@TiO2 by cobalt sulfophthalocyanine and investigation of photocatalytic activity of oxygen evolution under visible light

In the present study, magnetic photocatalysts, Magnetite@SiO2@TiO2-CoPcS (Mag@S@T-CoPcS) were synthesized, as a magnetic photocatalyst, and utilized for photocatalytic oxygen evolution under visible irradiation. Different methods were used to characterize the developed nanocomposites, such as Fourier transform infrared (FT-IR), energy-dispersive X-ray (EDX) spectroscopies, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, transmission electron microscopy (TEM), and inductively coupled plasma-optical emission spectroscopy (ICP-OES). A vibrating sample magnetometer (VSM) was used for conducting magnetic measurements of the prepared nanocomposites, and the maximum saturation magnetization was obtained as 8 and 10 emu g-1 for Mag@S@T-CoPcS and Fe3O4@SiO2@TiO2 (Mag@S@T) nanocomposites. The UV-Vis reflectance results revealed a bandgap of 1.7 eV for Mag@S@T-CoPcS nanocomposites. The amount of oxygen evolution for the Mag@S@T-CoPcS nanocomposite with different amounts of AgNO3 as the electron acceptor was measured by an oxygen meter under blue light emitting diodes (LED) irradiation. The rate of oxygen evolution for the Mag@S@T-CoPcS nanocomposite in the presence of AgNO3 0.05 M was 2.4 mg L-1 being higher than the oxygen amount produced with Mag@S@T. It was possible to easily recover the involved magnetic catalyst after three cycles by an external magnetic field.