Fast cost-effective synthesis of metal ions/biopolymer/silica composites by supramolecular hydrogels crosslink with superior tetracycline sorption performance

In this study, a fast one-pot method was developed for the preparation of Cu/CS/Si ternary composites, which can efficiently remove antibiotic tetracycline from aqueous solutions. Our results demonstrated that the Cu and its content in the composites played a significant role in determining the physical properties and internal morphology of the Cu/CS/Si composites, which subsequently affected the efficiency of the composites for the sorptive removal of tetracycline. Among the studied composites, Cu3-CS2-Si materials had the largest sorption capacity for tetracycline (1076.7 mg/g) with a fast sorption kinetics (>99% in 30 min) under a broad working pH range (5-10). The results from the batch sorption experiments, together with spectroscopic and microscopic analyses, collectively indicated that Cu-tetracycline inner-sphere surface complexation through Cu-O bond was responsible for the tetracycline sorption on Cu3-CS2-Si. In addition, the Cu3-CS2-Si showed an excellent reusability in removing tetracycline. The desired sorption and reuse properties, coupled with the facile and costeffective synthesis method, indicated that Cu/CS/Si composites have a promising potential for the efficient removal of tetracycline from contaminated solutions.