Photocatalytic performance of CdS nanomaterials for photodegradation of organic azo dyes under artificial visible light and natural solar light irradiation

2017 ◽  
Vol 28 (23) ◽  
pp. 17421-17441 ◽  
Author(s):  
Teeradech Senasu ◽  
Suwat Nanan
Keyword(s):  
Visible Light ◽  
Azo Dyes ◽  
Photocatalytic Performance ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

scholarly journals Comparison between the photocatalytic degradation of single and binary azo dyes in TiO2 suspensions under solar light irradiation

2015 ◽  
Vol 5 (4) ◽  
pp. 579-591 ◽  
Author(s):  
Ohm-Mar Min ◽  
Li-Ngee Ho ◽  
Soon-An Ong ◽  
Yee-Shian Wong
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Azo Dyes ◽  
Azo Dye ◽  
Oxygen Demand ◽  
Light Irradiation ◽  
Solar Light ◽  
Acid Orange 7 ◽  
Solar Light Irradiation

Textile industries discharge a large quantity of colored wastewater which is harmful to the ecosystem. In this study, two kinds of dyes were investigated: the mono azo Acid Orange 7 (AO7) and diazo Reactive Green 19 (RG19). The photocatalytic degradation of single (AO7, RG19) azo dye and binary (AO7 and RG19 mixture) azo dye aqueous solutions was photocatalyzed by commercial titanium dioxide (TiO2, P25) under solar light irradiation. The objectives of this study are to compare the photocatalytic degradation between single and binary azo dye aqueous solution and to study the various parameters such as the effect of different initial azo dye concentrations, different initial azo dye pH values, and compare the adsorption capacity of azo dyes with and without solar light irradiation, which influences the photocatalytic activities of single and binary azo dye aqueous solutions in a TiO2 suspension. The results showed that photocatalytic degradation of AO7 and RG19 in a single azo dye aqueous solution was faster than a binary azo dye solution under the solar light irradiation process. Chemical oxygen demand results revealed that complete mineralization could be achieved for both AO7 and RG19 azo dyes under solar light irradiation within 22 hours.

Sodium Ligninsulfonate-assisted Synthesis of Lithium Bismuthate/bismuth Oxide Microspheres and Solar Light Photocatalytic Performance

2021 ◽  
Vol 13 ◽  
Author(s):  
C.H. Yu ◽  
Y.J. Mao ◽  
Z.Y. Xue ◽  
J.L. Kong ◽  
H.Y. Li ◽  
...  
Keyword(s):  
Waste Water ◽  
Bismuth Oxide ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectrum ◽  
Light Irradiation ◽  
Solar Light ◽  
Hydrothermal Temperature ◽  
Solar Light Irradiation ◽  
Duration Time ◽  
Photocatalytic Removal

Background: Great attention has been paid to the environmental pollution by organic dyes which are difficult to be degraded in natural environment and have been an unavoidable and urgent global problem. It is essential to develop green waste water treatment technology with high removal efficiency and low cost to protect surroundings and human health. Objective: The aim of the research is to synthesize lithium bismuthate/bismuth oxide microspheres with good photocatalytic performance for the removal of gentian violet (GV). Methods: Lithium bismuthate/bismuth oxide microspheres were successfully prepared by a sodium ligninsulfonate-assisted hydrothermal synthesis route. The lithium bismuthate/bismuth oxide microspheres were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FTIR) and solid UV-vis diffuse reflectance spectrum. Results: XRD pattern and SEM observation show that the lithium bismuthate/bismuth oxide microspheres are composed of cubic LiBi12O18.50 and monoclinic Bi2O3 with the diameter of 250 nm-1 μm. Irregular microscale and nanoscale particles are formed under low hydrothermal temperature, low sodium ligninsulfonate concentration and short duration time. With increasing the sodium ligninsulfonate concentration, hydrothermal temperature and duration time, irregular particles are transferred into microspheres. Lithium bismuthate/bismuth oxide microspheres possess a band gap energy of 1.85 eV suggesting good visible light absorption ability. The photocatalytic removal ability for GV is enhanced by prolonging light irradiation time and microspheres dosage. GV solution with the concentration of 10 mg•L-1 is able to be totally degraded by 10 mg lithium bismuthate/bismuth oxide microspheres in 10 mL GV solution under solar light irradiation for 6 h. Conclusion: The lithium bismuthate/bismuth oxide microspheres show good photocatalytic removal ability toward GV in waste water under solar light irradiation.

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