Greatly enhanced tribocatalytic degradation of organic dyes by Fe2O3 nanoparticles through Ti and Al2O3 coatings

Abstract

Tribocatalysis has emerged as a cutting-edge technology for treating wastewater with high concentration organic dyes, while potential secondary pollution from catalysts due to wear and tear has caused much concern. Presently, cost-effective and eco-friendly Fe₂O₃ nanoparticles have been explored for tribocatalytic degradation of organic dyes, in which home-made Teflon magnetic rotary disks have been adopted in magnetic stirring, Ti and Al₂O₃ disks have been coated separately on the bottoms of glass beakers. Suspended with Fe₂O₃ nanoparticles in glass beakers with glass bottom, Ti and Al₂O₃ coatings, 40 mg/L Rhodamine B (RhB) was degraded by 40.9%, 98.6% and 99.7% after 4 h of magnetic stirring, respectively; 20 mg/L methyl orange (MO) was degraded by 66.4%, 95%, and 92.5% after 11 h of magnetic stirring, respectively. According to EPR analyses, superoxide radicals generated by Fe₂O₃ under magnetic stirring were substantially increased in the presence of Ti and Al₂O₃ coatings. Given the eco-friendly and scalable nature of Ti and Al₂O₃ coatings, these results demonstrate a promising strategy for eco-friendly natural mineral materials to utilize mechanical energy for large-scale environmental remediation.