Gingerbread ingredient-derived carbons-assembled CNT foam for the efficient peroxymonosulfate-mediated degradation of emerging pharmaceutical contaminants

Abstract

This article reports on the macronization of self-supported 3D CNT foam inter-connected by heteroatom-enriched porous shells derived from renewable baking ingredients via mild pyrolysis. The synthesized hybrids enabled disintegrating peroxymonosulfate (PMS) into reactive oxidants (sulfate radicals, hydroxyl radicals, and singlet oxygen) for the degradation of atenolol, iopamidol, metformin, trimethoprim, and phenol in water. Hierarchically structured nitrogen- and oxygen-doping significantly enhanced adsorptive and catalytic performance whereas the magnetic 3D framework promoted mass transport, multicycle use and induced synergetic effects via the Me-Nx-C interfaces. The samples were highly efficient for degradative removal of model pollutants at low catalyst and PMS dose. The catalyst loading, PMS dose, contact time, and temperature positively influenced the removal potency while pH and water matrix governed the rates differently. Spin trapping, oxidant quenching and solvent isotope effect study coupled with liquid chromatography and Fourier transform ion cyclotron resonance mass spectrometry analysis suggested the footprints of transformation products via a dual-mode (radical and non-radical) activation of PMS. This durable, magnetic carbofoam might be a promising catalyst for the oxidative abatement of pharmaceutical micropollutants from contaminated waters.