Photodegradation of acid orange 7 from aqueous solution under visible light irradiation using nanosized ZnO/chitosan/graphene oxide composite

In this study, the degradation of Acid Orange 7 (AO7) in aqueous solutions by iron(III) under activation by persulfate (PS, S2O82-) oxidation and Visible (Vis) light (≥420 nm) exposure was performed. The efficiency of different systems including Fe3+/Vis, Fe3+/PS, PS/Vis and Fe3+/PS/Vis has been evaluated. It was found that the efficiency of Fe3+/PS and PS/Vis system was low, and only about 48% of AO7 was oxidized within 20 min of experiment time under Fe3+/Vis system action, and it was further improved to almost 95% within 20 min by Fe3+/PS/Vis system. Various process-dependent parameters, such as PS, Fe3+, dye concentration as well as initial pH were investigated to optimize the process. As results indicated, the dye's degradation efficiency increased with the increase of PS and Fe3+ concentration over the tested range. The pH had an insignificant effect on the degradation of AO7. The effect of inorganic anions was also investigated and the suppressive effects of inorganic anions can be ranked in an ascending order of Cl−≈NO3−<SO42−<HCO3−≈HPO42−.Forcitation:Heng Zhong, Jun Li, Hui Zhao, Lei Sun, Aihua Xu, Dongsheng Xia, Nevsky A.V. Degradation of acid orange 7 in aqueous solution under presence of iron (III), persulphate and visible light irradiation. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 3. P. 48-54.

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Fabrication of monoclinic BiVO4 photocatalyst film and its photocatalytic activity for organic pollutant removal

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-8065 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Saranyoo Chaiwichian ◽

Buagun Samran

Keyword(s):

Visible Light ◽

Visible Light Irradiation ◽

Average Particle Size ◽

Pollutant Removal ◽

Light Irradiation ◽

Average Particle ◽

Film Sample ◽

Acid Orange 7 ◽

Acid Orange ◽

X Ray

Abstract Monoclinic BiVO4 photocatalyst films decorated on glass substrates were successfully fabricated via a dip-coating technique with different annealing temperatures of 400 °C, 450 °C, 500°C, and 550 °C. All of the physical and chemical properties of as-prepared BiVO4 photocatalyst film samples were investigated using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectra techniques. The results revealed that the as-prepared BiVO4 photocatalyst film samples retained a monoclinic phase with an average particle size of about 50 – 100 nm. Moreover, the BiVO4 photocatalyst film samples showed a strong photoabsorption edge in the range of visible light with the band gap energy of 2.46 eV. The photocatalytic activities of all the film samples were tested by the degradation of model acid orange 7 under visible light irradiation. The BiVO4 photocatalyst film sample annealed at a temperature of 500 °C showed the highest photoactivity efficiency compared with other film samples, reaching up to 51%within 180 min. In addition, the stability and reusability of BiVO4 photocatalyst film sample made with an annealing temperature of 500 °C did not show loss of photodegradation efficiency of acid orange 7 after ten recycles. A likely mechanism of the photocatalytic process was established by trapping experiments, indicating that the hydroxyl radical scavenger species can be considered to play a key role for acid orange 7 degradation under visible light irradiation.

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