الفهرس 
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Abstract
Thesis aims to synthesize of ZnO nanoparticles from (zinc acetate dihydrate) which modified by different percentages of MCM-41 like 1 wt%, 3 wt%, 5 wt% and 8wt%. and synthesize of ZnO from other salts ((zinc nitrate hexahydrate and zinc sulfate heptahydrate) and its modification by 3wt. % MCM-41 in presence of templates. These composites used for the photocatalytic degradation of MB and RB dyes.
Structural characterization of the prepared samples was determined using TEM, SEM, X‐ray and FTIR analysis.
1-Presence of absorption peak at 438 cm-1 in IR spectra assigned to ZnO for all samples. The Si-O-Si from MCM-41 are observed at 1430, 1027 and 913cm-1, where that the band 1430, 1027 and 913 cm-1 observed in the samples 3% and 5% MCM-41 /ZnO were attributed to symmetric and asymmetric strecheting vibration of Si-O band, respectively.
2-For X‐ray diffraction patterns, Presence of peaks at 2θ = 31.6, 34.2, 36.3, 47.4, 56.76, 62.9, 66.18, 68.1 and 69.1o, which are characteristic for ZnO nanostructures with hexagonal wurtzite crystal type. The intensity of hexagonal peaks of (ZnO) decrease by increasing wt. % MCM-41 content especially at 5 wt.%.
3-The results obtained from TEM analysis reveal the hexagonal shapes of ZnO and finger print of MCM-41 for all samples. And crystallite size of the samples decreases with amount MCM-41 content, which agrees with ray diffraction the results of XRD.
4- The results of SEM images reveal that ZnO from zinc acetate and zinc nitrate is composed of dense hexagonal nanoparticles with smooth surface, while that from zinc sulfate was amorphous. The SEM image of 3 wt. % MCM/ZnO from zinc acetate shows that nanocomposites were irregular and similar hexagonal nanoparticles, while ZnO from zinc nitrate and sulfate by MCM-41become amorphous, but 3 wt.% MCM-41/ZnO from zinc nitrate with template he shape become Long range order.
5-The results of UV-Vis - diffuse reflectance spectra of MCM-41/ ZnO, confirm that the band gab of pure ZnO, (1wt% MCM-41, 3wt% MCM-41, and 5wt. % MCM-41)/ZnO was 3.2, 3.1, 2.99 and 3.17 eV respectively.
The photocatalytic activity of the prepared MCM-41/ ZnO from Zinc acetate, zinc nitrate and zinc sulfate catalysts was measured by the photocatalytic degradation of methylene blue (MB) and rhodamine B (RB) under UV/visible Light, the results have proved that: The photodegradation of MB and RB increases gradually with increasing the amount of MCM-41 loaded on ZnO till reach the maximum 3 wt. % MCM-41 which has the highest ZnO dispersion so photocatalytic activity increases. ZnO photocatalyst from acetate was better than other salts for the photocatalytic degradation of MB ZnO from acetate was modified by 3 wt. % MCM-41 but that from nitrate and sulfate not modified this may be due to the organic source of acetate which gives the highest ZnO nanoparticles dispersion on MCM-41 surface. 3 wt. % MCM-41/ZnO from zinc nitrate with 0.5g PVA as template increase the photocatalytic activity for the photocatalytic degradation of MB dye. d. The optimum pH for degradation of methylene blue and rhodamine B was 8 and 4 respectively.The photodegradation of MB and RB increases with increasing of weight of photocatalysts and decreas with .increasing dye concentration