| Abstrak/Abstract |
The photocatalytic degradation of hazardous organic dyes was investigated using green-produced MnFe2O4/TiO2 nanocomposites, which demonstrated magnetic reusability and separability, making them efficient photocatalysts for rapid UV degradation. The MnFe2O4/TiO2 diffraction peaks indicated a single-phase cubic spinel structure, with crystallite sizes spanning from 5.3 to 7.1 nm. The TiO2 anatase phase showed typical peaks at 25.8° and 48.2°, corresponding to the (110) and (200) diffraction planes, respectively. The transmission electron microscopy image of MnFe2O4/TiO2 revealed inter-grain aggregation between the particles. The particle size of MnFe2O4/TiO2 exhibited a slight increase from 30 to 40 nm. MnFe2O4 appeared as black spheres, whereas TiO2 appeared as grey circles. X-ray spectroscopy confirmed the matching of chemical elements. The bandgap of the nanocomposites decreased from 2.9 to 3.2 eV after the surface treatment with TiO2, indicating an electronic transition between the two components. Furthermore, the addition of TiO2 affected the saturation magnetization, which ranged from 7.6 to 11.2 emu/g. The nanocomposites clearly displayed superparamagnetic-like behavior. A photocatalytic investigation showed that MnFe2O4/TiO2 nanoparticles exhibited higher photocatalytic activity than MnFe2O4 nanoparticles. Methylene blue dye was degraded by 98 % using the MnFe2O4/TiO2 nanocomposites after 2 h of UV exposure. This photodegradation was further investigated using a Langmuir–Hinshelwood kinetic model, and it was discovered that the rate constant (Kapp) increased with the TiO2 concentration. The nanocomposites maintained over 90 % photocatalytic efficiency without any significant degradation after three reuse cycles. Therefore, green-synthesized MnFe2O4/TiO2 nanocomposite photocatalysts for dye degradation are highly promising for the removal of harmful organic dyes from the environment. |
