Mussel-inspired magnetic pullulan hydrogels for enhancing catalytic degradation of antibiotics from biomedical wastewater

Abstract

Magnetic hydrogels are fascinating materials that can be used as Fenton-like catalysts to remove antibiotics from biomedical wastewater. However, the poor distribution of magnetic nanoparticles in hydrogel matrix and weak mechanical properties severely confine their applications from lab to industrial scale. Here, we presented for the first time the facile fabrication of mussel-inspired magnetic pullulan (MMP) hydrogels using polydopamine as a bridge to build a relationship between Fe3O4 and pullulan matrix, which could solve the common problems of magnetic hydrogels and enhance catalytic degradation of tetracycline (TC) simultaneously. Degradation results proved that our catalytic system (MMP4) showed superior TC degradation efficiency (86.32% within 60 min). Theoretical studies verified that TC could act as an electron donor and the produced electrons from TC were transferred via polydopamine to the iron species through π-Fe interactions. Besides, MMP4 exhibited excellent reusability and stability that no apparent decrease in degradation efficiency was observed after 5 cycles. Altogether, our findings provide a simple but effective strategy to design magnetic hydrogel catalysts for enhancing antibiotic degradation from biomedical wastewater.