Enhanced Photocatalytic Degradation of Methyl Red Dye Via Hydrothermally Synthesized Manganese Tungstate

This study reports the hydrothermal synthesis, characterization, and photocatalytic performance evaluation of manganese tungstate (MnWO₄) for the degradation of Methyl Red (MR) dye under UV light irradiation. MnWO₄ was synthesized using cetyltrimethylammonium bromide (CTAB) as a morphology-directing agent, and the resultant nanoparticles were characterized using XRD, FTIR, SEM, and UV-DRS techniques. The XRD results confirmed the formation of monoclinic phase MnWO₄ with high crystallinity, while SEM analysis revealed nearly spherical particle morphology. Optical measurements indicated both direct (2.96 eV) and indirect (1.65–2.62 eV) band gaps, suggesting the material’s visible-light-responsive nature. The photocatalytic experiments demonstrated that MnWO₄ achieved approximately 98% degradation efficiency of MR within 180 minutes under UV-C light. The enhanced activity was attributed to the improved crystallinity, controlled morphology, and the formation of defect-related active sites. These results indicate that hydrothermally synthesized MnWO₄ is a promising photocatalyst for wastewater treatment applications involving azo dye contaminants.