الفهرس 
Literature ReviewOnly 14 pages are availabe for public view
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Abstract
Nanocrystalline materials are showing great prospects in industry and technology. This is mainly because they have some unique properties which are not shown by the bulk crystalline materials. Nanomaterials represent almost the ultimate in increasing surface area. Substances with high surface area have enhanced chemical, mechanical, optical and magnetic properties, and this can be exploited for a variety of structural and non-structural applications.
Throughout this work it was found that:
A- For the pure NiO thin films
- Successful preparation of nanocrystalline NiO thin films with different thickness 30, 50 and 80 nm have been done on glass substrate by DC magnetron sputtering technique.
- Deposition times of 600, 900 and 1200 sec results in the films of 30, 50 and 80 nm thicknesses with particle size around 8, 10 and 12 nm respectively.
- The average crystallite size was found to be 7.82, 8.7 and 9.91 nm for NiO thin films with 30, 50 and 80 nm film thickness respectively.
- It was found the optical band gap decreasing from 3.74, 3.48 to 3.37 eV by increasing the film thickness of NiO thin films from 30, 50 to 80 nm respectively.
- The photocatalytic performance of NiO thin films were tested in the presence of methyl green dye (MG) as a pollutant example in waste water using 18 W UV lamp under different operating conditions like pollutant concentration, pH and reuse cycle.
- The results show that the nanocrystalline NiO thin films are very efficient and highly stable as a photocatalyst.
B- For the Nb-doped NiO thin films
- Pure and 4 wt % Nb-doped NiO thin films at different substrate temperatures (25, 100 and 200 °C) have been successfully prepared by simultaneous deposition of Ni and Nb in the presence of oxygen gas (O2) on glass substrate by DC/RF magnetron sputtering technique.
- The average crystallite size was found to be 9.91, 8.81, 9.61 and 10.24 nm for the pure and Nb-doped NiO thin films deposited at 25, 100 and 200°C substrate temperatures respectively.
- The cross sectional view of the deposited thin films showing a gradual decrease from 80, 70, 50 to 30 nm for the pure and Nb-doped NiO thin films deposited at 25, 100 and 200°C substrate temperatures respectively.
- It was found that the optical band gap decreasing from 3.6, 3.48, 3.42 and 2.99 eV for the pure and Nb-doped NiO thin films deposited at 25, 100 and 200°C substrate temperatures respectively.
- The photocatalytic degradation of MG dye using the doped thin films under 500 W halogen tungsten lamp as a source of visible light showed that Nb-doping and increasing the substrate temperatures plays a significant role to increase the photocatalytic efficiency from 67, 80 to 100 % within 3 hrs for the films prepared at 25, 100 and 200°C respectively.
C- For the pure CuO thin films
- Nanocrystalline CuO thin films (Tenorite phase) were deposited for 600, 1200 and 1800 sec on glass substrate using RF magnetron sputtering technique.
- The increase in average crystallite size from 6.67, 8.87 to 9.09 nm and the thickness from 160, 320 to 490 nm was observed with the increase in deposition time from 600, 1200 to 1800 sec respectively.
- . The optical band gap was decreased from 2.2, 1.88 to 1.73 eV as the film thickness was increased from 160, 320 to 490 nm respectively.
- The photocatalytic degradation of methylene blue (MB) dye using the prepared thin films under 200 W halogen tungsten lamp as a source of visible light under different operating conditions like pollutant concentration, light intensity and reuse cycle.
- CuO thin film of minimum thickness of around 160 nm responded as a best catalyst for MB degradation.
- The films were very stable and have a specialty to be recycled without much loss of their photocatalytic activity.
D- For the Ag-doped CuO thin films
- Pure and zerovalent Ago doped CuO thin films have been prepared by simultaneous deposition of Cu and Ag in the presence of oxygen gas (O2) on glass substrate by DC/RF magnetron sputtering technique.
- The average crystallite size was found to be 8.70, 7.69 and 6.88 nm for the 0, 2.5 and 5.4 wt % Ag-doped CuO thin films respectively.
- It was found that the optical band gap decreasing from 1.84, 1.77 to 1.61 eV by increasing Ag-doping from 0, 2.5 to 5.4 wt % respectively.
- The X-ray photoelectron spectroscopy (XPS) was employed for the confirmation of zerovalent Ago furthermore the chemical state of Cu 2p3/2 and O1s were analyzed.
- The photocatalytic efficiency of the deposited thin films was examined at different concentration of MB dye and various pH of the solution under the sun light.
- The degradation observation indicated that the photocatalytic efficiency of CuO thin films was greatly enhanced due to zerovalent Ago doping and further enhancement was noticed by varying pH of the solution.