Visible-light-induced degradation of Rhodamine B by Ba doped ZnO nanoparticles

Abstract

In the present work, ZnO and Ba doped ZnO nanoparticles (Ba/ZnO) were synthesized by the sol-gel approach. The effects of Ba doping and calcination temperature on photodegradation of Rhodamine B (RhB) were examined under visible light irradiation. In the optimized synthesis conditions, 0.1% Ba loading, and 400 °C calcination temperature, the photocatalyst revealed considerable activity toward photodegradation of RhB. The photocatalytic process by optimal photocatalyst was further modeled and optimized by Response Surface Methodology. The maximum removal efficiency of 98.40% was obtained for catalyst dosage of 350 mg L−1, initial RhB concentration of 4.11 mg L−1, the irradiation time of 68 min, and pH 8. In addition, for 0.1% Ba/ZnO photocatalyst, the activity under visible light was near to UV-A light with a considerable reduction in photoluminescent spectra (PL) compared to neat ZnO. A comparison of PL spectra of RhB and RhB/0.1%Ba/ZnO showed considerable quenching of the light-emitting broad peak of RhB for the later confirming the photosensitizer effect of adsorbed RhB for efficient visible-light-driven degradation of dye.