Etude de l'effet du pHde millieu réactionnel sur les propriétés des nanoparticules d'oxyde mérallique obtenue par méthode verte

This study explores an eco-friendly approach to synthesizing zinc oxide (ZnO) nanoparticles using plant extracts as an alternative to conventional physical or chemical methods. ZnO nanoparticles were produced via a green synthesis process using Portulaca oleracea (purslane) leaf extract at varying pH levels of 4, 6, 9.5, and 11. The impact of pH on the optical and structural characteristics of the synthesized nanoparticles was investigated. Ultraviolet-visible (UV-Vis) spectrophotometry and Fourier-transform infrared (FTIR) spectroscopy techniques were employed to analyze the optical properties, while scanning electron microscopy (SEM) and X-ray diffraction (XRD) were utilized to study the structural properties. Additionally, the photocatalytic performance of the synthesized ZnO nanoparticles was evaluated through the degradation of methyl orange dye.
The characterization results confirmed the successful biosynthesis of ZnO nanoparticles with sizes ranging from 22.17 to 27.38 nm. UV-Vis analysis revealed maximum absorption in the 350-380 nm range, indicative of the Zn-O bond. FTIR spectra exhibited a distinct peak at 474 cm-1, attributed to Zn-O vibrations. SEM images revealed that the obtained nanoparticles generally exhibited spherical or oval morphologies. The synthesis pH significantly influenced the optical and morphological properties of the ZnO nanoparticles. The results demonstrated the high performance of the green-synthesized ZnO nanoparticles in dye degradation applications.