Synthesis of nanosized MgMn₂O₄ spinel by co-precipitation in the ultrasonic field

Nanosized MgMn₂O₄ spinel particles were synthesized by co-precipitation in an ultrasonic field. The Bragg peaks on the diffractogram of the synthesized product were in good agreement with the reference model of MgMn₂O₄ spinel with a tetragonal structure. The average size of MgMn₂O₄ crystallite was calculated according to the Debye–Scherrer equation, which was approx. 24 nm. Nanosized spinel particles were tested as sodium percarbonate activators during the oxidative degradation of the xanthene dye rhodamine B (advanced oxidation − ultrasound/MgMn₂O₄/Na₂CO₃ × 1.5 H₂O₂). The degradation degree of rhodamine B was 98%, and the rate constant was 4.1 × 10⁻³ s⁻¹ at the sodium percarbonate concentration of 5 mM, the catalyst content in the reaction medium of 1 g/L, and the treatment time of 3600 s.