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Abstract
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Undoped and Pr-doped ZnO nanoparticles were prepared using a simple sonochemical method, and their
sonocatalytic activity was investigated toward degradation of Acid Red 17 (AR17) under ultrasonic (US)
irradiation. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform
infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy
(TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The extent of sonocatalytic degradation
was higher compared with sonolysis alone. The decolorization efficiency of sonolysis alone, sonocatalysis
with undoped ZnO and 5% Pr-doped ZnO was 24%, 46% and 100% within reaction time of 70 min, respectively. Sonocatalytic degradation of AR17 increased with increasing the amount of dopant and catalyst
dosage and decreasing initial dye concentration. Natural pH was favored the sonocatalytic degradation
of AR17. With the addition of chloride, carbonate and sulfate as radical scavengers, the decolorization
efficiency was decreased from 100% to 65%, 71% and 89% at the reaction time of 70 min, respectively, indicating that the controlling mechanism of sonochemical degradation of AR17 is the free radicals (not pyrolysis). The addition of peroxydisulfate and hydrogen peroxide as enhancer improved the degradation
efficiency from 79% to 85% and 93% at the reaction time of 50 min, respectively. The result showed good
reusability of the synthesized sonocatalyst.
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