Development of biogenic mediated Ag/ZrO₂ nanocomposite photocatalyst for degradation of toxic dyes in textile effluents

Abstract

Zirconium oxide (ZrO2) nanoparticles doped with silver (Ag) were synthesized utilizing Vitis vinifera leaf extract, offering a non-toxic and cost-effective production method. These nanoparticles were evaluated for their photocatalytic activity against both cationic (CR, EY, MO) and anionic (CV, MG, MB) dyes, alongside electrochemical impedance spectroscopy studies. The incorporation of silver into ZrO2 aimed to enhance the photocatalytic efficiency, particularly under visible light activation, for the significant removal of toxic contaminants. Analysis employing UV-vis spectroscopy and a pseudo-first-order kinetics model revealed that sunlight exposure notably improved dye degradation. Various techniques were employed to assess the physicochemical characteristics, indicating the reduction process in the chemical reaction and confirming nanoparticle formation through chemical bonding, as evidenced by peaks in the IR spectrum ranging from 450 to 660 cm−1. Furthermore, analysis of the UV–vis spectrum revealed bandgaps of 5.1 eV and 4.56 eV, confirming tetragonal and cubic crystal structures with crystalline sizes of approximately 15.7 nm and 17 nm for ZrO2 and Ag–ZrO2 nanoparticles, respectively. Electrochemical impedance spectra demonstrated that the addition of Ag to Zr notably improved charge transfer and electron separation processes.