Chitosan/PVA-supported silver nanoparticles for azo dyes removal: fabrication, characterization, and assessment of antioxidant activity

Abstract

With the advancement of technology, studies in the field of nanotechnology have attracted great interest in recent years. The fact that nanomaterials have superior advantages over micromaterials provides a wide range of uses. Green synthesis is an effective way to prepare nanomaterials with an easy, fast, and environmentally friendly method. Within the scope of the study, AgNPs were synthesized using basil extract and combined with chitosan/PVA as a support material. By using chitosan/PVA support materials, the surface area of AgNPs was increased and it was aimed to improve their properties. The synthesized AgNPs@chitosan/PVA nanocomposite was characterized using various methods. In the UV-Vis spectrum, an absorbance peak was observed at 430 nm for the AgNPs@chitosan/PVA nanocomposite, and the particle size was determined as 25.10 nm according to TEM results. In addition, the photocatalytic and antioxidant activities of AgNPs@chitosan/PVA nanocomposite were investigated. The antioxidant activity of the AgNPs@chitosan/PVA (100 μg mL⁻¹) nanocomposite against DPPH and H₂O₂ was determined as 89.18% and 71.87%, respectively. The photocatalytic activity of the AgNPs@chitosan/PVA nanocomposite against methylene blue (MB), methylene red (MR), methylene orange (MO), safranin, and crystal violet (CV) dyes was 77%, 85%, 79%, 54%, and 9%, respectively. While the highest photocatalytic activity was observed against MR dye, very low photocatalytic activity was observed for CV. In light of the results obtained, it can be said that the AgNPs@chitosan/PVA nanocomposite has the potential to be used as an antioxidant agent and photocatalyst.