Eco-Friendly Photoactive Foils Based on ZnO/SnO₂-PMMA Nanocomposites with High Reuse Potential

In the last decades, water pollution from different industries has been one of the largest environmental issues. Many efforts have been made to develop technologies to remove toxic pollutants from the contaminated waters, which are direct threats to the aquatic environment and human health. Among different technologies, heterogeneous catalysis has shown to be very effective for water purification. The main issue regarding this method is the water recovery after the treatment, which is a very expensive and laborious procedure but can be addressed by the immobilization of photocatalytic particles on the support material. Here, we present efficient and green technology for water purification based on ZnO/SnO₂-poly(methyl methacrylate) (PMMA) nanocomposite foils utilizing superior photocatalytic properties of coupled ZnO and SnO₂ photocatalysts. We investigated the influence of the ZnO/SnO₂ nanoparticle concentration on the removal efficiency of methylene blue dye and found exceptional removal efficiency for even very low ZnO/SnO₂ nanoparticle loadings. The investigated foils were found to be highly reusable, with no change in performance after five successive usages. The composition, optical properties, surface morphology, and surface roughness of the foils were characterized by X-ray diffraction, UV–vis spectroscopy, scanning electron microscopy, and atomic force microscopy. The thermal measurements performed with differential scanning calorimetry suggested the reinforcement effect of ZnO/SnO₂ nanoparticles on the PMMA matrix, which is essential for practical applications of the foils.