Contact Lenses–TiO<sub>2</sub> Nanocomposites\nfor a Sustainable Wastewater Remediation

Rising\nplastic waste from products such as contact lenses underscores\nthe need for innovative recycling solutions. This study presents a\nsustainable approach to produce reusable photocatalytic hybrid nanocomposites\nfor water treatment through the use of waste contact lenses. TiO<sub>2</sub> nanoparticles were uniformly integrated into postused contact\nlenses via a controlled spray deposition technique, resulting in nanocomposites\nwith different spray times (10, 15, or 20 min). The innovative polymeric\nhybrids were comprehensively characterized from a morphological, structural,\nand chemical standpoint using techniques such as scanning and transmission\nelectron microscopy, thermogravimetric analysis, X-ray diffraction\nanalysis, Raman spectroscopy, Z-potential analysis, UV–vis\nspectroscopy, and Fourier transform infrared spectroscopy. The UV-photocatalytic\nperformance of the resulting systems was successfully tested on two\ncommon pollutants: methylene blue (a cationic dye) and sodium dodecyl\nsulfate (an anionic surfactant). The highest efficiency was obtained\nthrough the 20 min spray-coated lenses, able to degrade ∼100%\nof MB and ∼60% of SDS within 3 h of UV-light irradiation. The\ndifference in the photocatalytic efficiency was attributed to the\nelectrostatic interaction between the individual pollutant and the\nmaterial’s surface. In addition, the antibacterial activity\nwas assessed on Escherichia coli, a\nwell-known indicator of water fecal contamination. This research paves\nthe way for recycling plastic waste through an affordable and cost-effective\nproduction method that aligns with the circular economy principles.