Microwave synthesized strontium hexaferrite 2D sheets as versatile and efficient microwave catalysts for degradation of organic dyes and antibiotics

Abstract

Microwave catalysis is extremely lucrative due to prompt mineralization and superior efficiency. Ideal microwave catalysts should possess crystalline nature, large surface area, room temperature ferromagnetic, high dielectric properties apart from structural stability at elevated temperature. In the present article, the candidature of microwave synthesized strontium hexaferrite 2D sheets (2D SFO) has been explored as microwave catalysts for the degradation of a host of organic dyes and antibiotics. Malachite green (MG) and nile blue A (NB) in particular exhibited 99.8% and 97.6% degradation, respectively. Degradation reaction is established to follow pseudo-second-order kinetics. Total organic carbon (TOC) measurements hint at 52% and 60% mineralization for MG and NB, respectively. Liquid chromatography-mass spectroscopy (LCMS) measurements indicate the reaction pathways via intermediates and eventual mineralization to CO₂ and H₂O. Mott-Schottky measurements along with scavenger tests hint that both hydroxyl and superoxide radicals participate in the reaction. Having superior efficiency apart from the versatile nature of the 2D SFO microwave catalyst, the present research will guide to the emergence of microwave catalysis as a new technology.

Keywords: Antibiotics; Microwave catalysis; Microwave synthesis; Organic dyes; Strontium hexaferrite.