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, Cu–CS–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 Cu–CS–Si. In addition, the Cu–CS–Si showed an excellent reusability in removing tetracycline. The desired sorption and reuse properties, coupled with the facile and cost-effective synthesis method, indicated that Cu/CS/Si composites have a promising potential for the efficient removal of tetracycline from contaminated solutions.