Vol. 7, Issue 1, Part B (2025)

Zinc-based molybdate and tungstate nanomaterials have emerged as efficient photocatalysts for environmental remediation due to their tunable electronic structures and high chemical stability. The present study investigates the synthesis of rare-earth doped ZnMoO₄ and ZnWO₄ nanomaterials and evaluates their photocatalytic degradation performance of organic dyes under visible light irradiation. A facile co-precipitation method followed by controlled calcination was employed to synthesize well-crystalline nanocomposites doped with selected rare-earth ions (Eu³⁺ and Tb³⁺). Structural characterization using X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed phase purity and nanoscale morphology. UV-Vis diffuse reflectance spectroscopy (DRS) revealed a significant red-shift in absorption edge upon doping, indicating enhanced visible light absorption. Photocatalytic activity was assessed using methylene blue (MB) as a model pollutant under visible light; doped samples showcased superior degradation efficiency compared to undoped hosts. Kinetic analysis demonstrated that rare-earth doping effectively reduced recombination rates of photogenerated charge carriers, improving photocatalytic efficiency. The results highlight that rare-earth doped zinc-based molybdate-tungstate nanomaterials are promising visible-light active photocatalysts for environmental applications such as wastewater treatment. The study provides insights into dopant-mediated charge dynamics and lays groundwork for practical implementation of these nanophotocatalysts