Pyridyl-containing polymer blends stabilized iron phthalocyanine to degrade sulfonamides by enzyme-like process

•FePc-P4VP/PAN NFs were prepared as a biomimetic catalytic system by mimicking enzymes.•The coordination structure of the FePc-pyridine was to mimic the active sites of the enzyme.•The PAN molecular chain intertwined with P4VP to mimic the protein skeleton structure of the enzyme.•FePc-P4VP/PAN NFs are efficient and stable for sulfonamides degradation.•Transformation products of SQX were finally transformed to small molecule acids.

Self-purification of an aquatic environment occurs through the enzymatic functioning of microorganisms; however, nowadays, pollutant release has exceeded the self-purification capacity in the aquatic environment, and some antibiotics, such as sulfonamides, can inhibit microorganism reproduction. Therefore, to enhance the self-purification capacity in an aquatic environment, we developed a biomimetic catalytic system by mimicking the catalytic mechanism of enzymes. This system is based on iron phthalocyanine coordinates on poly (4-vinylpyridine)/polyacrylonitrile nanofibers. The resulting coordination structure was characterized by digital microscopy, X-ray photoelectron spectroscopy etc. The catalytic system was highly active and stable for sulfonamide degradation, even in the presence of inorganic salts at neutral pH. Gas chromatography-mass spectroscopy and high-definition electrospray ionization mass spectrometry proved the heterolytic cleavage of the peroxide OO bond to generate high-valency iron-oxo species instead of homolytic cleavage to generate OH in a catalytic system. Detailed density functional theory calculations, ultra-performance liquid chromatography and high-definition mass spectrometry showed that the aromatic compounds were degraded to small acids by the electrophilic attack of iron-oxo active species.

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