The Influence of Catalyst Concentration on Methylene Blue Photodegradation using Magnetically Reusable CoFe2O4/TiO2 Nanocomposites Synthesized via Green Route Utilizing Moringa Oleifera Yumna Haura Zahra (a), Dianiwati (a), Citra Dwi Lestari (a), Rizal Ahmad Fauzi (a), Nurul Imani Istiqomah (b), Deska Lismawenning Puspitarum (b)(c), Edi Suharyadi (b), Hasniah Aliah (a*)
(a) Department of Physics, Faculty of Science and Technology, UIN Sunan Gunung Djati, Bandung, Indonesia
(b) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia
(c) Department of Physics, Institute Teknologi Sumatera, Lampung, Indonesia
Green-synthesized CoFe2O4/TiO2 nanocomposites utilizing Moringa oleifera leaf extract were successfully fabricated using the coprecipitation method. The green approach-based nanocomposites synthesizing is considered to be an eco-friendly and cost-effective method to fabricate nanocomposites compared to the other conventional methods. Nanocomposites exhibited excellent photocatalytic and reusability performance under UV irradiation. Various techniques were employed to characterize the properties of green-synthesized CoFe2O4/TiO2 nanocomposites, such as UV visible spectroscopy, X ray diffraction (XRD), transmission electron microscopy, Fourier transform infrared spectroscopy, and vibration sample magnetometer. Photocatalytic activity of CoFe2O4/TiO2 nanocomposites in degrading methylene blue (MB) dye has been successfully carried out. The investigation of photocatalytic activity was carried out with several variations of the mass of the CoFe2O4/TiO2 nanocomposite of 0.02, 0.04, 0.06, 0.08, and 0.1 gram. The results of the characterization using XRD showed that the crystallite size of CoFe2O4/TiO2 was 11.3 nm. The magnetic hysteresis curve showed that CoFe2O4/TiO2 had a high saturation magnetization of 27 emu/g and a coercivity of 200 Oe. The optical bandgap energy for CoFe2O4/TiO2 was in the range 3.6 until 3.8 eV. The characterization of photocatalyst activity showed an increase in the percentage of degradation by the increase of photocatalyst concentration. Variations in the mass of the catalyst affect the degradation process, with a mass of 0.06 gram being the effective mass in degrading MB with the degradation efficiency of 97%. CoFe2O4/TiO2 nanocomposites can be recycled and used three times with a degradation efficiency above 95%. Nanocomposites can still be reused to degrade MB again with degradation efficiency of almost constant. Therefore, the green synthesized CoFe2O4/TiO2 has great potential as magnetically separable and reusable photocatalyst for water purification.
Keywords: CoFe2O4/TiO2- Green Synthesis- Methylene Blue- Photocatalyst- Nanocomposites
