Photocatalytic dye degradation efficiency and reusability of potassium polyacrylate hydrogel loaded Ag@ZnO nanocomposite

Abstract

The widespread use of nonbiodegradable synthetic dyes in various industries has led to significant toxic contamination and water pollution. The release of these dyes into aquatic environments poses serious risks to human health and ecosystems. To address this issue, rapid and efficient techniques for dye removal or transformation are required. In this article, we present a pioneering approach for the synthesis of a highly efficient photocatalyst material, PPAH/Ag@ZnO nanocomposites, for the degradation of organic dyes in wastewater. By integrating silver (Ag) and zinc oxide (ZnO) nanoparticles within the potassium polyacrylate hydrogel (PPAH) matrix, a two-step method was employed to create stable and effective photocatalytic nanocomposites. The successful formation of PPAH/Ag@ZnO nanocomposites was confirmed through comprehensive characterization using UV–visible spectroscopy, FTIR, XRD, and SEM techniques. The photocatalytic performance of the PPAH/Ag@ZnO nanocomposite was evaluated for the degradation of o-toluidine blue (o-TB) and 4-bromophenol (4-Bph) under sunlight. The experimental results demonstrate that the PPAH/Ag@ZnO nanocomposite effectively degrades 98.77% of o-TB and 98.05% of 4-Bph. Moreover, the kinetics of the photocatalytic degradation reactions were investigated, revealing apparent reaction rate constants of 0.0229 and 0.018 min⁻¹ for the degradation of o-TB and 4-Bph, respectively. Additionally, the reusability of the prepared PPAH/Ag@ZnO photocatalyst was evaluated over 5 consecutive cycles, demonstrating its exceptional effectiveness and stability. This innovative approach with hydrogel-based nanoparticles offers a potential breakthrough in the field of photocatalysis for addressing water contamination caused by organic dyes.