Mn 3 O 4 and Ag 2 MnO 4 Nanoparticles Loaded on g-C 3 N 4 as Magnetic Catalysts for Sonodegradation of Dyes

New magnetic Mn₃O₄/g-C₃N₄ and Ag₂MnO₄/g-C₃N₄ nanocomposites have been synthesized based on Mn(II) Schiff base complex and used for sonodegradation of methylene blue (MB) and methyl orange (MO) dyes in aqueous solution. Ag₂MnO₄ nanoparticles (NPs) have been synthesized from Mn₃O₄ NPs and AgNO₃ under ultrasonic irradiation for the first time. The results indicate that the sonodegradation method of dyes in the presence of Mn₃O₄/g-C₃N₄ and Ag₂MnO₄/g-C₃N₄ nanocomposites is better than solar degradation processes. The better photodegradation rates for MB and MO dyes observed in the presence of Ag₂MnO₄/g-C₃N₄ (k= 0.0916 min^-1) and Mn₃O₄/g-C₃N₄ (k= 0.0381 min^-1), as compared to pure Mn₃O₄ and Ag₂MnO₄ compounds The synthesized nanocomposites are good fluorescent materials.