عقيل مهدي جريو الدحيدحاوي

Abstract In this study, copper oxide nanostructures were prepared by an easy, simple, short time and economical electrochemical method using polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) as stabilizing agents. Copper is used as precursor as melt anode electrode during electrolysis to prepare CuO particles. Characterization of the prepared CuO NPs was studied by field emission scanning (FE-SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The FE-SEM images of CuO / PVA and CuO / PVP were both rectangular parallel plates and regular cubes. TEM images prepared from CuO / PVA and CuO / PVP. It had an average size of 30-50 nm. The XRD results revealed the cubic structure of CuO nanoparticles. The optical properties of the prepared CuO / PVA and CuO / PVP nanoparticles were studied through UV / VIS spectroscopy. The optical band gap was found to be (3.60) eV and (3.65) eV for CuO / PVP and CuO / PVA respectively. Dye solar cells were designed using CuO / PVA and CuO / PVP as positive electrode (front electrode) and graphite as cathode (back electrode) Deposition on the surface of ITO glass in the presence of two types of natural dyes, such as cabbage and spinach, and iodine / iodine electrolyte solution. The PV cells prepared using spinach dye were more efficient. It is noticed from the data that the dye has a very important role in improving the efficiency of the solar cell, as the cells made from spinach gave a much higher efficiency than cells prepared from the red cabbage dye in all cases.

Abstract: Aluminum oxide Nanoparticles (Al2O3 NPs) were prepared by electrochemical method in solution contain NaNO3 as electrolyte and Poly Vinyl Alcohol (PVA) as stabilizer. The synthesized Al2O3 NPs were characterized by FTIR, SEM, TEM and AFM studies. FTIR spectrum of Al2O3 NPs exhibited absorptions at (605 and 883 CmG1) are attributed to Al-O bond. SEM micrographs givesirregular agglomerated small (flower) like structure. From TEM study the size of Al2O3 NPs was found to be <40 nm and the shape of nanoparticles was uniform thread like structure . The average size of synthesized Al2O3 NPs from AFM study was found to be 41.16 nm.

Abstract Zinc oxide nanoparticles(ZnO NPs) were prepared by electrochemical method in solution contain NaNO3 as electrolyte and Poly vinyl pyrrolidone (PVP) as stabilizer. The prepared ZnO NPs were characterized by EDX,SEM,TEM, and AFM studies .EDX-Spectrum of ZnO nanoparticles exhibited signals of zinc and oxygen only , that means the sample of ZnO NPs having high purity . SEM micrographs gives a homogeneous particles distribution and having sheets like structure. From TEM study the size of ZnO NPs was found to be about 60 nm and the shape of nanoparticles was a bipyramid like shape. The average size of synthesized ZnO NPs from AFM study was found to be 60.99 nm, this result was agreement with result that obtained from TEM .

In this research, zinc oxide nanoparticles (ZnO NPs) were made utilizing an electrochemical method. Which has the advantages of being quick, simple, producing no side products, and being inexpensive. Advanced techniques such as x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultravioletvisible (UV-Vis), energy dispersive x-ray (EDX), and atomic force microscopy (AFM) were used to characterize the generated zinc oxide. Using methyl orange dye, the analysis showed that the shape of zinc oxide nanoparticles was rice-like and the band gap value was 3.62. ZnO NPs is used in dye-sensitized solar cells (DSSCs) it has many advantages including its ease of use and low cost, its ability to be integrated into buildings, and its fantastic performance under diffuse and indoor lighting. DSSCs have attracted more attention and have been deemed viable alternatives to conventional photovoltaic devices. The solar cell's efficiency (η %) and fill factor with methyl orange as a dye were 2.3, and 74.1, respectively.

Nanomaterials have excellent chemical and physical properties and have wide applications in the modern time. One of the important methods for preparing nanocomposites (Al2O3/ZnO) is the electrochemical deposition method, which is characterized by speed, ease and inexpensive. The nanocomposite characterizes by Advanced techniques such as x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis), energy dispersive x-ray (EDX), and atomic force microscopy (AFM). The analysis showed that the shape of nanocomposite was Nano rod, the band gap value was 3.23(e.v) and average crystal size was (8.4 nm).

In this study, CuO/SnO2 nanocomposites were synthesized by an easy, low cost and short time electrolytic method for fabrication dye-sensitized solar cells ( DSSCs). The characterization of the prepared CuO/SnO2 NCs were studied by several techniques. The FE-SEM images of CuO/SnO2- PVA and CuO/SnO2-PVP NCs were both rectangle and regular cube shapes respectively. HRTEM images of synthesized CuO/SnO2 NCs show homogeneous cubic shapes had an average size of 30-40 nm. The XRD results show the monoclinic-tenorite phase of CuO crystal structure and the SnO2 crystal structure is in rutile tetragonal SnO2. The optical properties of the prepared CuO/SnO2- PVA and CuO/SnO2-PVP NCs were studied through UV / VIS spectroscopy. The optical bandgap was found to be 3.15 eV and 3.18 eV respectively. Dye-sensitized solar cells were fabricated using CuO/SnO2- PVA and CuO/SnO2-PVP NCs as anode electrodes (front electrode) and graphite as cathode (back electrode) in the presence of two kinds of natural dyes, these are pomegranate and parsley dyes, and iodine / iodate electrolyte solution. The photovoltaic parameters were determined from I-V plots of the DSSCs indicated that the DSSCs prepared from parsley dye were more efficient. The reason may be attributed to the fact that parsley chlorophyll dye contains an abundance of electrons capable to providing the DSSCs with these electrons better than the anthocyanin dye found in pomegranate