الفهرس 
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Abstract
electrodeposition is one of the most important metals and has wide applications in corrosion resistance, decrease wear and friction, enhances heat tolerance, and for decoration. The electrodeposition bath constituents, pH and the deposition potential affect the characteristics of the deposit and hence, its catalytic properties. So, the main aim of this work is producing non-precious metal with high abundant non-noble catalyst having high catalytic activity. The electrolyte composition is very important in the deposition process. The electrodeposition of Ni were carried out from two different solvents namely acetate buffer solution and ethaline deep eutectic solvent. Different morphologies and sizes were obtained from the two different solvents at different pH and different deposition potentials. The electrocatalytic activity were tested of the deposited Ni nanoparticles from the two different solvents towards methanol oxidation and water splitting reactions HER and OER as one of the most important application for energy storage of renewable and green energy applications. The following parts shown below describe the concise of introduction, experimental and the obtained results in this work. Chapter one “ INTRODUCTION “ This chapter includes information about nanomaterials, their applications and methods of preparation. Further it contains the illustration of the electrodeposition process from aqueous and deep eutectic solvents. Also, it provides the factors affecting the deposition process and the literature review of Ni electrocatalysts that are used for methanol oxidation and water splitting reactions of HER and OER. tal “ “ Experimen Chapter two It introduces the method of preparation of the two different electrolytes, the first one is acetate buffer solution with different pH values and the second is ethaline deep eutectic solvent. It describes the uses and importance of the electrodeposition and characterization of Ni@PGE nanoparticles by SEM , TEM, EDX , XRD and the elucidation of the electrode reactions. Chapter three“ Results and Discussion “ The collected data and results are discussed in this chapter. It represents Cyclic Voltammetry investigation for Ni ions in acetate bath and in ethaline solvent. The obtained results reveal that the reduction of Ni+2 from acetate bath occurs at higher potential than the reduction of Ni+2 from ethaline solvent. It shows the effect of scan rate on the reduction process of Ni species from the two different solvents. It illustrates that the reduction of Ni+2 from the two solvents at PGE is irreversible charge-transfer process and the diffusion coefficient for Ni+2 from the acetate bath is 4.76*10-7 cm2 s-1 and 1.2*10-7 from ethaline. The optimization of the electrodeposition process was studied at different pH and deposition potential from acetate and ethaline bath. The characteristics of the deposits were performed via SEM, TEM, EDX and XRD. The smallest crystallite size and more compact surface from the two solvents was chosen for further experiments. The electrocatalytic activity towards water splitting reactions HER and OER were studied at PGE coated by the deposited Ni nanoparticles from the acetate bath and ethaline solvent. The kinetics parameters j0 and α were calculated for both Ni@PGE from acetate and ethaline. The Ni@PGE deposited from ethaline has the best kinetics parameters towards HER and OER. The stability towards HER and OER was studied using the chronoamperometry technique and exhibiting excellent stability and durability. The characteristics of the deposited Ni nanoparticles from the two solvent were performed using SEM, EDX to display the morphology and the elemental composition of the deposited films at PGE. The crystallite size were calculated from XRD data. TEM analysis was measured of the deposited Ni nanoparticles from ethaline to show the internal structure. It also includes the comparison between the electrocatalytic activity of Ni@PGE nanoparticles from acetate and Ni@PGE nanoparticles from ethaline towards methanol oxidation in acidic media and showed their stability. It was found that Ni@PGE nanoparticles from ethaline have higher catalytic activity and higher current density towards methanol oxidation reaction in the acidic media compared with the other deposit but its stability needs to be improved. The obtained results showed that the deposited non-precious Ni nanoparticles from ethaline solvent have higher catalytic activity than the commercial noble Pt with low loading in some researches. Further this work illustrates the effect of the deposition potentials on the catalytic activity towards methanol oxidation. As a conclusion the deposition of non-precious Ni from two different solvents gives different characteristics at different conditions and produces different catalytic activity towards HER, OER in the alkaline media and methanol oxidation in the acidic media. Inspection of the data established in literature and comparing it with our data, we found that the results recorded in this thesis is the first data produces high catalytic activity for methanol oxidation in the acidic media by non-precious metals without adding noble metals like Pt.