Dy-doped Y2O3 coated biosilica nanostructures with variable Dy3+ contents were synthesized by a facile hydrothermal technique. The products were characterized by means of energy dispersive X-ray photoelectron spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy techniques. XRD demonstrated that the particles were crystallized excellently and attributed to the cubic phase of Y2O3. The substitution of Dy3+ ions into Y2O3 lattice caused a redshift in the absorbance and a decrease in the band gap of as-prepared coated compounds. The pore volume and BET specific surface area of Dy-doped Y2O3 -coated diatomite were greater than uncoated biosilica. The sonophotocatalytic activities of as-synthesized specimens were evaluated for the degradation of Reactive Blue 19. The effect of various specifications such as ultrasonic power, various scavenger, and catalyst amount was investigated. The results revealed that diatomite coated with Dy3+-incorporated yttrium oxide nanoparticles could be utilized in various experimental cycles with no significant decrease in photocatalytic activity.
