ZnSe:Fe/ZnS-PVA Materials Are Synthesized as Fenton Photocatalysts for the Degradation of Methylene Blue under Visible Radiation

This study describes the production of ZnSe:Fe/ZnS-PVA nanoparticles utilizing poly(vinyl alcohol) (PVA) as a stabilizer in an environmentally acceptable, safe, economical, and easy chemical approach that does not include organometallic compounds. X-ray diffraction (XRD) analysis reveals that the ZnSe:Fe/ZnS-PVA nanoparticles have a cubic structure. The absorption edge in the UV–vis absorption spectrum was used to calculate the optical band gap energy (Eg), which decreased as particle size increased. When Fe-doped ZnSe particles were coated with an additional ZnS layer, their size increased and Eg decreased, causing a shift from blue to green under UV light. Variations in ZnS concentration and Fe doping altered the surface bonding of the nanoparticles and improved the band structure by reducing the band gap, which improved the material’s ability to absorb light in the visible light range and changed its photocatalytic properties. When the electron donor molecule oxalic acid (H2C2O4) and nanoparticles are employed as Fenton photocatalysts in the methylene blue (MB) degradation process under visible light, the Fenton photocatalytic process follows a pseudo-first-order kinetic equation. ZnSe:Fe/4ZnS-PVA nanoparticles exhibited superior photocatalytic activity compared to ZnSe-PVA and ZnSe:Fe-PVA, achieving an apparent rate constant of 0.0100 min–1, which is 4.9 times higher than that of ZnSe-PVA NPs. After 180 min of response, roughly 90% of the MB was degraded. These findings show promise for the material’s practical application in the remediation of hazardous organic dyes in water.