Author name:
حيدر عبد الكريم يوسف
Supervisor name:
خلود عبد صالح السعدي
Abstract:
يعتبر اوكسيد النحاسوز واحدا من المواد ذات الاستخدامات العلمية المتعددة الاغراض وذات الاهمية الصناعية الكبيرة ,ومنها استخدامه كمتحسس للغازات وفي العوامل المساعدة وكذلك في انتاج الواح الطاقة الشمسية ويدخل وبصورة كبيرة كمحطم للصبغات العضوية في مجال الكيمياء | Cuprous oxide (Cu2O) has been extensively studied because of its potential use in several electronic applications, which include solar cells and gas sensors. This Thesis is devoted to the synthesis, characterization of nano - structured cuprous oxide by using a simple electrochemical cell with a potassium chloride solution as an electrolyte, the electro cell contains a two high purity copper electrodes as a sheet form in different areas at varying sizes the area of the cathode was twice of the area of anode , the two electrodes zone were separated using a fine diameter silica diaphragm,Within this broad scope , the Thesis focuses on : • Production of different shape nano - crystals (Cu2O) and investigation of the correlation between experimental parameters and resulting microstructure.• Production of highly purity nano - crystalline Cu2O powder, with the estimation it’s by the available investigation instruments.• Study the different parameters, current density, bath temperature, KCl concentration , types of additives , time of precipitation, and there’s effects on the shape ,quantity ,surface roughness, powder color, on the Cu2O powder. Models have been proposed for the nano - crystal formation validated by several techniques uses such as X - ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), and Fourier Transform Infra - Red spectroscopy (FTIR). The produced nanocrystals show good crystallinity with Cu2O purity and Copper oxide semiconductor nanoparticles were prepared by electrochemistry using galvanostatic and potentiostatic approaches. The optimum deposition conditions ( electrolyte composition , medium pH , type of additives, electrodes area ,current density , temperature of the electrolyte and applied potential of the cell) , to prepare the Cu2O nano particles have been identified; in particular the conditions that allow getting this product by using KCl ,(PVA ,SDS ,and glycerin as emulsifying agent) have been well identified for the first time. The configuration of deposited Cu2O , purity and amounts. These values depend on the electro deposition conditions such as the pH of the solution, the deposition potential and temperature. Where the study results showed that there is direct effect of these factors, it has been observed that the sizes of the precipitate crystalline decreased with increasing current density and especially at high bath temperatures its ranged about 10 - 20 nm , in addition to the effect of the percentage of additives emulsifier agents the best results at poly vinyl alcohol.. The X - ray diffraction pattern and 2? values reflect that the high purity of the deposit where obtained, without any of the other undesirable products like CuO, CuCl2 and CuCl. Also the FTIR analysis was considered. the effect of additives of the type of emulsifier on the crystalline form of the deposit, the PVA produced of the Star (Branches) crystals shape, the addition of the SDS compound leads to the form of the cubic , and the glycerin product the binary pyramid crystals shape.. Finally the conditions effect on the surface roughness of the precipitated powder also discussed. Depending of the electro - deposition conditions, different surface morphologies with various preferential crystal orientations were obtained for the temperatures of the electro - deposition of 80 °C , pH = 8 - 9 , The influence of several deposition parameters of the Cu2O, such as applied potential, pH, the temperature of the bath , the chemical composition, grain size and orientation parameters of the sample was systematically studied using X - Ray Diffraction , Atomic Force Microscopy, Transmission Electron Microscopy ,Fourier Transmission Infra - Red, and scanning electron microscopy.
