Green synthesis of silver nanoparticles (AgNPs) was accomplished using different volumes of cauliflower extract and 0.001 M silver nitrate solution at 80°C for 15 min. A brownish-red solution of AgNPs formed was tested by ultraviolet-visible absorption spectroscopy, Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Surface plasmon resonance of AgNPs appeared at 416 nm. Also, the kinetic of AgNPs formation was studied and follows a sigmoidal pattern. Storing time was studied for the freshly prepared AgNPs after 60 days. FTIR analysis shows the adsorption of active components on AgNPs surface, and these components are responsible for reduction besides working as a stabiliser like a capping agent, also FTIR analysis of AgNPs after storage showed no change in peaks location. The SEM exhibited a globular shape of AgNPs, and the particle size ranged from 25 to 100 nm, while the XRD particle size calculation was 25 nm with cubic phase lattice.The antibacterial activity was tested against Gram-positive and-negative bacteria showed an inhibition zone of 16-27 mm and the antibacterial activity tested for the same bacteria after storage for about 10 months showed an inhibition zone of 6-10 mm.

Tea waste and active carbon manufactured from dates' stone were used as adsorbents for removal Safranin O dye and the results were compared. Safranin O dye removal efficiency was studied by batch adsorption. The experimental results displayed that the removal efficiency of dye on the two adsorbent were greatest at high acidic solution of SO solution for tea adsorbent, while for Activated Carbon at high alkalinity for the same dye. This study shows the adsorption equilibrium isotherms were followed Freundlich and Langmuir isotherms, where safranin O dye adsorption obey Freundlich isotherm. The effect of temperature was studied and thermodynamic parameters were calculated.

The current work involves modification of zinc oxide by doping silver, this was achieved by photodeposition method. Modified zinc oxide was investigated using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Both of ZnO and Ag doped ZnO was fabricated on a cotton texture. The photocatalytic activity of these materials was investigated by following the decolorization of congo red from simulated industrial wastewater. The decolorization of congo red over fabricated-ZnO-Ag was more efficient in comparison with non- fabricated catalysts. Different reaction parameters were undertaken including the effect of pH of the solution, irradiation time and the effect of light intensity. Complete dye removal over fabricated materials took three hours while it took 4.5 for non-fabricated materials.

The current work involves modification of zinc oxide by doping silver, this was achieved by photodeposition method. Modified zinc oxide was investigated using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Both of ZnO and Ag doped ZnO was fabricated on a cotton texture. The photocatalytic activity of these materials was investigated by following the decolorization of congo red from simulated industrial wastewater. The decolorization of congo red over fabricated-ZnO-Ag was more efficient in comparison with non-fabricated catalysts. Different reaction parameters were undertaken including the effect of pH of the solution, irradiation time and the effect of light intensity. Complete dye removal over fabricated materials took three hours while it took 4.5 for non-fabricated materials.

Two films of ZnO-Ag/polystyrene (ZnO-Ag/PS) and ZnO/polystyrene (ZnO/PS) have been prepared and the photodegradation ability of stabilized catalysts was evaluated for methylene blue (MB) degradation. The efficiency of ZnO improved against recombination of electron-hole pair by modification of catalyst surface with Ag photodeposition to be more resistant towards photocorrosion. ZnO-Ag catalyst was characterized by SEM and EDS analysis to show high roughness of this catalyst and Ag deposited on the surface was 2% (molar ratio). ZnO-Ag/PS and ZnO/PS composites were made as films and were then analyzed by FTIR spectra that showed the interaction of ZnO and ZnO-Ag with polystyrene appeared in the range of 400-620 cm -1 , XRD pattern indicated the presence of Ag nanoparticles on the surface of ZnO and ZnO/PS film has maximum absorbance at 376 nm in UV-VIS spectra. This value shifted to 380 nm because of the photodeposition. The photocatalytic reaction was depicted using MB in the UVirradiation action of stacked films in MB solution. The result showed that both ZnO-Ag/PS and ZnO/PS films gave efficiency to remove MB by 97% and 70%, respectively. The reusability test of the films showed that ZnO-Ag/PS was more resistant than ZnO/PS. The presence of Ag also increased the efficiency in photodegradation and resistance against photocorrosion.