dc.description.abstract |
Water plays major role in the day-to-day activities of the societies and other living things.
However, fresh water is becoming polluted due to increased discharge from
manufacturing industries in the form of effluents into the environment. Therefore, the
effluent needs to be treated before discharged to the environment. In this work, Zinc
oxide (ZnO) and Al doped ZnO photocatalysts were synthesized by sol–gel method using
zinc acetate as precursor for degradation of methylene blue dye (one of toxic effluents
from textile industries). The characterization of the synthesized samples were performed
by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), scanning
electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and UV visible (UV
VIS) spectroscopy. The XRD result revealed the presence of a hexagonal wurtzite
structure. The FT-IR results showed predominant absorbance peaks at maximum peak
864cm-1, 712cm-1 and 506 cm-1, which corresponds for Al-O, Al-O-Zn and Zn-O bond
stretching, respectively. Similarly, the result obtained from UV-VIS revealed the bandgap
energy of ZnO changed from 3.05 eV to 3.1 eV, due to doping effect by Al. SEM images
show the morphology of ZnO and Al-ZnO NPs. EDS mapping confirms the presence of
O and Zn. Finally, the photocatalytic performance of the samples were investigated over
a wide range of operating parameters and it has been obtained over 99.3 % degradation of
methylene blue in 120 minutes of irradiation time, under light intensity of 5810 lux, using
2% Al doped ZnO nanoparticles at 65 °C reaction temperature. Degradation efficiency
increased with increasing light intensity, dopant amount, reaction temperature, and
contact time. |
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