Sonochemical synthesis and characterization of Mn2+Mn3+6[SiO4]O8 nanostructures and their application as photocatalyst for degradation of water-soluble organic pollutants below simulated sunlight

Abstract

In the present study, novel Mn2+Mn3+6[SiO4]O8 (braunite, MSO) nanostructures were fabricated by a simple and affordable sonochemical method. The uniformity, structure, shape, and size of the product are affected by sonication time and power. Mn2+Mn3+6[SiO4]O8 were used as a photocatalyst in the visible region due to their suitable bandgap (2.52 eV). The photocatalytic tests indicate that Mn2+Mn3+6[SiO4]O8 nanostructures can degrade organic dyes, such as Eriochrome Black T (EBT) and Erythrosine (ER) in high values. Therefore, the degradation rate is 94.8% under ideal circumstances, which include 70 mg of catalyst and 10 ppm EBT. According to the kinetics study, the superior rate constant (k = 0.0217 min−1) results in the maximum photocatalytic efficiency (94.8%). The recycle test unveils that Mn2+Mn3+6[SiO4]O8 is so stable and after five cycles, the photocatalyst efficiency decreased by 14.9 and 14.2% for EBT and erythrosine, respectively. Superoxide radicals were found to be the most active radicals implicated in the degradation of EBT and erythrosine by the scavenger's test.

Keywords

• Mn2+Mn3+6[SiO4]O8 Nanostructures
• Sonochemical
• Organic dyes
• Recyclability
• Scavengers