Polymer quantum dots doped in metal organic framework for sono-catalytic degradation of sulfamethazine

Abstract

Sulfamethazine as one of sulfa drugs could be discharged in the surface, drinking and ground water, to be accumulated in the organs, migrating later to foodstuff and eventually raises the possibility of developing a variety of infectious diseases in human beings and animals. On the other hand, polymer quantum dots (PQDs) as a type of carbon-based nanostructures are exhibited with excellent photoluminescent properties, abundancy, easy of surface decoration and biocompatibility with low toxic effects. Herein, simple and environmentally benign technique was reported to reuse acrylate waste fibers (AWF) for nucleation of PQDs (size = 5.6 nm, zetapotential = -6 to -11). The so-nucleated PQDs were successively doped within metal organic framework (namely, MIL-125-NH2) to prepare PQDs@MIL-125-NH2 composite, to be applicable as sono-photocatalyst for degradation of sulfamethazine. Successive doping of PQDs within MIL-125-NH2 was approved via different instrumental analysis such as Electron Microscope, X-ray diffraction, and infrared spectroscopy. Kinetic parameters for sono-photocatalytic degradation of sulfamethazine were also estimated. The recyclability of PQDs@MIL-125-NH2 composite was also approved. PQDs@MIL-125-NH2 composite as sono-photocatalyst exhibited the highest affinity for full degradation (99.9%) within 90 min of rate constant of 28.79 ± 1.21± 1.5 × 10−3 min−1. For PQDs@MIL-125-NH2 composite, the percentage of sono-photocatalytic degradation for sulfamethazine was lowered from 99.9% to be 96% to be reduced with only 4% after recycling for 5 times. Reaction mechanisms for ingraining PQDs and the sono-photocatalytic action of the prepared of PQDs@MIL-125-NH2 composite for degradation of sulfamethazine were elucidated.