Synthesis and Optimization of MnFe2O4 as a Catalyst for the Degradation of Methylene Blue Dye Putri Aisyah Ali (a*), Mustika Della Asti (a), Lina Mahardiani, S.T., M.Sc., Ph.D. (a)
a) Chemistry Education Study Program, Faculty of Teacher Training and Education (FKIP), Universitas Sebelas Maret
*putriaisyahali[at]student.uns.ac.id
Abstract
Spinel ferrite materials, MFe2O4, were synthesized and evaluated as heterogeneous catalysts for the degradation of methylene blue dye. The growing concern over water pollution from textile dye effluents has driven the need for efficient and reusable catalytic systems. In this study, MnFe2O4 were prepared via the coprecipitation method using NaOH as the precipitating agent. The synthesized materials were characterized using FTIR, XRD, BET, SEM-EDX, and UV-DRS, and subsequently tested as catalysts through a Fenton-like oxidation process. MnFe2O4 were successfully obtained as dark brown powders. FTIR analysis confirmed the formation of characteristic metal-oxygen bonds, including Mn-O and Fe-O vibrations in MnFe2O4, consistent with a spinel structure. XRD patterns revealed that both materials adopted a cubic spinel phase with crystallinity values of 53,66% for MnFe2O4, indicating well-defined phase formation. BET measurements yielded specific surface areas of 7,01 m2/g for MnFe2O4. SEM-EDX analysis showed that MnFe2O4 displayed a broader morphological distribution ranging from near-spherical to irregular shapes with varying particle sizes. UV-DRS analysis determined optical band gap values of 2,56 eV for MnFe2O4, classifying the material as semiconductors. Catalytic performance was evaluated by varying reaction time and H2O2 volume. MnFe2O4 demonstrated superior performance, reaching a degradation efficiency of 83.32% at 60 minutes with 8 mL H2O2. This results indicate that spinel ferrite is promising heterogeneous catalysts for dye degradation via the Fenton-like process.
