Fabrication and performance of novel multifunctional sodium alginate/polyvinylpyrrolidone hydrogels

In this work, a novel alginate/polyvinylpyrrolidone (SA/PVP-Fe) hydrogel spheres were prepared by cross-linking with Fe2+ ions after blending sodium alginate with polyvinylpyrrolidone. The degradation performance of the hydrogels was assessed through the degradation of phenol, achieving 100% degradation and about 64% total organic carbon (TOC) mineralization within 60 min (initial concentration of phenol = 20 mg/L; H2O2 concentration = 5 mM; initial pH = 6.5; catalyst dosage = 1.0 g/L). Degradation kinetics were monitored using high-performance liquid chromatography (HPLC). The structural and chemical properties of the hydrogels were characterized using scanning electron microscopy (SEM), energy spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Inductively coupled plasma mass spectrometry (ICP-MS). Additionally, the hydrogels exhibited multiple reuse cycles, albeit with a gradual decline in degradation performance. Mechanistic investigations revealed that the hydroxyl radical derived from the Fenton reaction was the primary active species responsible for the degradation process. This research provides valuable insights into improving the mechanical properties of sodium alginate hydrogels, opening up avenues for their practical applications.