Synthesis, characterization, and photocatalytic performance evaluation of manganese tungstate for methyl red dye degradation

Kayhan E., Kayhan M.

PAMUKKALE UNIVERSITY JOURNAL OF ENGINEERING SCIENCES-PAMUKKALE UNIVERSITESI MUHENDISLIK BILIMLERI DERGISI, cilt.2025, ss.1-7, 2025 (ESCI)

Özet

Abstract

The increasing prevalence of synthetic dyes in industrial wastewater presents significant environmental challenges because of the toxicity and lack of effectiveness of conventional treatment methods. Methyl red, a widely used azo dye, is particularly problematic due to its high chemical stability. In this study, manganese tungstate (MnWO₄) was synthesized using a coprecipitation method and evaluated for its photocatalytic activity in methyl red degradation through UV-C exposure. The synthesized MnWO₄ was characterized using several techniques, including Fourier transform infrared spectroscopy (FTIR), ultraviolet-diffuse reflectance spectroscopy (UV-DRS), and scanning electron microscopy (SEM). SEM analysis revealed the formation of needle-like, nanometer-sized MnWO₄ particles with high aspect ratios, which are expected to enhance photocatalytic efficiency. XRD confirmed the development of a highly crystalline pure MnWO₄ phase, and FTIR spectra showed characteristic peaks corresponding to Mn–O and W–O bonds. The UV-DRS results revealed that the material possesses a direct band gap of 3.18 eV, suitable for UV-C light absorption. Photocatalytic experiments demonstrated that MnWO₄ effectively degraded methyl red, with the removal efficiency reaching nearly 60% after 180 minutes of irradiation. These findings suggest that MnWO₄ is a promising photocatalyst for environmental remediation, offering a simple, costeffective solution for dye degradation in wastewater.