This presentation is about phtoocatalytic process and nanomaterials as photocatalyst. This is useful in the treatment of wastewater and environmental remediation applications.
6. Introduction
Nanotechnology is the control or
manipulation of materials in
nano-range.
The prefix “nano” generates from
Greek word “νᾶνος” (latin word
nanus) have meaning dwarf or a
little man denotes a number 10-9.
Nano means billionth part of a
meter (1*10-9).
Nanotechnology
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9. ¶ A process in which a substrate is
activated by light to facilitate or
modify the kinetics of a reaction is
called photocatalysis.
¶ The reaction mechanism have four
steps
Generation of electron and hole
pairs by the absorption of light
Charges separation
Transformation of electron and
hole pairs to the photocatalyst
surface
Charges utilization to intimate
redox reaction on the surface
Introduction
Photocatalysis
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10. Introduction
Band Gap Energy
Band gap energy is the range of several energy levels in a crystal that cannot be
possessed by an electron.
Band gap contrast of metal, semiconductors and insulators 10
24. Results and Discussion
Fourier Transform Infrared Spectroscopy
FTIR spectra of γ-Fe2O3, MnO2, Co3O4 and ZnO nanostructures 24
25. Results and Discussion
Fourier Transform Infrared Spectroscopy
FTIR spectra of FeCo2O4, MnCo2O4 and ZnCo2O4 nanostructures 25
26. Results and Discussion
Current-Voltage (I-V) measurement
The Fe2O3 and MnO2 having S-shaped curves show non-linear and non-ohmic nature and
reveals semi-conductor behavior while the Co3O4 and ZnO exhibit linear curves obey ohm’s
law and demonstrate conducting behavior.
I-V curves of γ-Fe2O3, MnO2, Co3O4 and ZnO nanostructures 26
27. Results and Discussion
Current-Voltage (I-V) measurement
I-V curves of FeCo2O4 MnCo2O4 and ZnCo2O4 is slightly S-shaped (non-linear or non-
ohmic behavior) which indicates the semi-conducting nature of the material.
I-V curves of FeCo2O4, MnCo2O4 and ZnCo2O4 nanostructures 27
31. Results and Discussion
Photocatalytic degradation
Photocatalytic degradation of MB for γ-Fe2O3, MnO2, Co3O4 and ZnO nanophotocatalysts
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Photocatalytic activity of the prepared oxides and mixed oxides was examined using
5ppm of methylene blue (MB) as a dye. Carry 60 ultraviolet spectrophotometer was
used to judge decrement in the absorption.
35. Spinel mixed oxides have superior photocatalytic activity than simple metal oxides.
Results and Discussion
Percentage degradation rate of MB at specific time intervals under different photocatalyst
(a) FeCo2O4, MnCo2O4 and ZnCo2O4 (b) Fe2O3, MnO2, Co3O4 and ZnO nanophotocatalysts
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36. Conclusion
Photocatalytic degradation capability of simple transition
metal oxides and spinel mixed metal oxides under visible
light irradiation have been studied.
spinel mixed oxides have superior photocatalytic activity
than simple metal oxides.
The enhanced photocatalytic behavior of spinel metal
oxides is attributed to …..
Small crystallite size
Increased surface area of nano-catalyst
High light absorption rate at the interface of photocatalyst
Decrease rate of reunion of charge carriers at the
interface of photocatalyst
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39. Acknowledgement
All praises and thanks to Allah Almighty who created the universe and knows whatever is in
it, hidden or evident, and who bestowed upon me the intellectual ability and wisdom to search
for its secrets.
Ever-Thankful, for His helps and bless. Many prayers for the Holy Prophet Muhammad ﷺ
( )
There are no proper words to convey my deep gratitude and respect for my thesis and
research advisor, Dr. Muhammad Farooq Warsi.
I am keenly thankful to the worthy chairman Department of chemistry, Professor Dr.
Muhammad Ashfaq for providing all the research facilities to complete this research project
in time.
XRD (QAU), FTIR (Women uni multan), IV (physics department, IUB), UV/VIS (IFS Sweden),
SEM and BET (Dr. Sonia American uni cairo Egypt) are also highly acknowledged for
providing these characterizations.
I want to give special gratitude to my sister, Wajeeha Shaheen.
. I would also like to thank Simab Gul, Hira and Attiya Rahman for their corporation.
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