Nanoarchitecturing bimetallic manganese cobaltite spinels for sonocatalytic degradation of oxytetracycline

Degradation of contaminants of emerging concern in aqueous media using bimetallic oxides is a promising novel strategy that requires engineering new catalytic routes in bimetallic oxides to perform advanced oxidation; however, several challenges to synthesizing and developing such materials with enhanced, sustainable catalytic features are still being investigated. This study presents the effective use of a manganese cobaltite bimetallic spinel compound for sonocatalysis. We prepared three morphologies of manganese cobaltite for using in the sonocatalytic degradation of oxytetracycline (OTC). The morphology of manganese cobaltite was tuned by changing the amounts of the Mn and Co precursors in the early stage of synthesis. Several manganese cobaltite spinels with different structures—porous layered-like cubes (MCO-PLC), layered-like ellipsoids (MCO-LE), and rough spheroids (MCO-RS) were obtained and characterized using various techniques. A promising catalytic degradation capability of MCO-PLC for OTC (10.0 mg L⁻¹) was obtained at a natural pH within 120 min. We also investigated the reusability of MCO-PLC sonocatalyst and metal (Mn and Co) leaching in water media. The sonocatalytic mechanisms and fragments produced from OTC during degradation were determined via electron paramagnetic resonance and gas chromatography-mass spectroscopy analyses.