Photocatalytic Performance of Silver-Doped Zinc Oxide Nanoparticles for Methylene Blue Degradation

The primary sources of water contamination are wastes from industrial regions, including pesticide residues, paper, organic textile, and pharmaceuticals. Specifically, organic dyes released by industries have the capacity to be harmful, biorecalcitrant, indestructible, fade-resistant, and pose a significant risk to human health. At 60 °C, Ag/ZnO nanoparticles with various Ag concentrations were prepared. Several characterization methods, including scanning electron microscopy (SEM), UV–vis spectroscopy, and X-ray diffraction (XRD), have been utilized to investigate the Ag/Zn-2. The progress of methylene blue decolorization was examined via UV–vis spectroscopy. The Ag/Zn-2 photocatalysts had a surface area of 89.5 m²/g and a crystallinity of 90%.The catalytic performance for the methylene blue (MB) was assessed. Ag/Zn-2, one of the photocatalysts, had the greatest rate of MB dye degradation, reaching 97.1% in 105 min. After five cycles, the Ag/Zn-2 catalyst showed improved structural stability and durability but lost appoximately 3.8% of its efficiency. The pseudo-1st order kinetic model with a rate constant (k) of 0.03304 min⁻¹ described superoxide and hydroxyl radicals as the main active species in the degradation process. When silver is introduced as a dopant to the zinc oxide crystal structure, the band gap energy is significantly lower, allowing for the absorption of a wider variety of light wavelengths. Furthermore, the presence of Ag helps to prevent electron-hole recombination, which can reduce the photocatalytic efficacy.This study presents a novel way to improve the photocatalytic properties of a basic metal–semiconductor material made from Rumex abyssinicus Jacq root extract, making it a suitable option for environmental remediation.

Graphical Abstract