Urea-assisted water electrolysis in an alkaline environment effectively treats urine-rich wastewater and prevents the release of ammonia gas and nitrate pollution into groundwater and drinking water; these contaminants typically result from the discharge of untreated urea into rivers and lakes. On the other hand, Urea-assisted water electrolysis is an efficient method for electrochemically producing hydrogen from water, while simultaneously cleans urea-polluted water. During this process, urea is oxidized at the anode to produce N? and CO?, while pure hydrogen is produced at the cathode and can be easily collected as a valuable green fuel. Compared to conventional water splitting, this method requires 70% less thermodynamic energy to produce H?. Expanding this technology to industrial applications, such as treatment of wastewater plants and farms, could prevent health problems and costs associated with toxic gas emissions, and contribute to the emerging hydrogen economy. In this thesis, two nickel-based bifunctional catalysts were synthesized, and their feasibility for use in the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) was investigated due to their superior electrocatalytic performance. In Chapter 1, an introduction to Urea-assisted water electrolysis and its importance is provided. In Chapter 2, a cerium-nickel bimetallic metal-organic framework (NiCe-MOF) was synthesized on nickel foam (NF) via a solvothermal method to enhance its conductivity and electrochemical properties. The prepared nanocomposite was characterized using various techniques, including X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and Field emission scanning electron microscope (FESEM). The structure of NiCe-MOF/NF was thereby determined. The electrocatalytic performance of the modified electrode toward UOR in an alkaline solution containing 0.5 M urea was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and other electrochemical methods. Compared to stepwise-modified electrodes, the urea oxidation current on NiCe-MOF/NF was substantially increased and exhibited high stability after 200 potential cycles between 0.0 and +0.8 V. Furthermore, chronopotentiometry (CP) performed at a constant current density of 20 mA cm?² showed a very small potential drop for NiCe-MOF/NF over 20 h, confirming its excellent stability. On the other hand, linear sweep voltammetry (LSV) studies showed excellent electrocatalytic performance towards HER (in KOH, 1 M), with an overpotential of 145 mV at a current density of 10 mA cm?². Furthermore, CP stability tests demonstrated good stability of the proposed catalyst during 20 h of HER operation. The fabricated two-electrode cell, consisting of (-)NiCe-MOF/NF?NiCe-MOF/NF(+), required only 2.22 V to reach a current density of 100 mA cm?² and exhibited excellent stability, with just a slight voltage drop after 20 h of Urea-assisted water electrolysis. The superior electrochemical performance toward urea oxidation and hydrogen evolution was attributed to the effective synergy between nickel and cerium within the MOF structure. In Chapter 3, a chalcogenide was employed in the preparation of an efficient bifunctional electrocatalyst for H2

      Treatment due to the limitations and side effects of organic drugs, the synthesis of metal complexes, that is, drugs based on metal has been given much attention and many successes have been achieved in this field. In this study, an Fe(III) complex of guaifenesin ligand (GFS) and 1, 10-phenanthroline ligand was synthesized and identified. The interaction between the metal complex of GFS with ct-DNA at pH 7.4 was investigated. According to the UV-vis spectra and comparison of the binding constants it was concluded that the complex can be interacted stronger in cancer cells media and low toxicity was observed in healthy cells. The results of circular dichroism (CD) showed groove binding mode. The interaction of the metal complex and the ligand with HAS was investigated by spectrofluorimety at three different temperatures. Thermodynamic parameters were calculated using the Van?t Hoff equation, and   ?H° and ?S° are positive which indicates that the interaction of Fe(III) complex with HSA is the hydrophobic. According to the results of CD the interaction between the metal complex of Fe(III) of GFS and HSA occurs and the percentage of alpha helix increases. It should be noted that during the interaction of HSA with Fe(III) metal complex of GFS, the secondary structure of HSA is stabilized.

   In this study, the synthesis of a Ce–La/Ca nanocatalyst via the co-precipitation method and its application in biodiesel production through the transesterification of rapeseed oil were investigated. To optimize the process, key parameters affecting the structure and performance of the nanocatalyst—including the molar ratio of precursor materials, precipitation temperature and time, stirring speed during precipitation, pH of the precipitating solution, calcination temperature and time, reaction temperature and time, methanol-to-oil molar ratio, and catalyst loading (wt%)—were considered as independent variables. The optimized catalyst was characterized using various analytical techniques, including XRD, BET, SEM, FT-IR, and EDX. XRD results confirmed the formation of a cubic fluorite crystalline phase. Both XRD patterns and SEM images revealed that the catalyst consists of nanoparticles with an average size of 10–15 nm. The specific surface area was measured to be 6.87 m²/g, indicating a suitable porous structure for efficient transesterification. Under optimal conditions—calcination at 650?°C for 3 h, reaction temperature of 60?°C, reaction time of 4 h, methanol-to-oil molar ratio of 15:1, and 5 wt% catalyst loading—a biodiesel yield of 98.6% was achieved. Additionally, the kinetics and thermodynamics of the transesterification reaction using rapeseed oil and the Ce–La/Ca catalyst were studied. Kinetic and thermodynamic analyses demonstrated that the catalyst exhibits high activity in facilitating the ester exchange reaction, delivering a significant conversion under the aforementioned optimal conditions. Furthermore, the catalyst could be successfully recovered and reused for four consecutive reaction cycles without a significant loss in catalytic activity—a notable advantage with considerable economic and environmental benefits. Subsequently, quantum chemical calculations were performed using Gaussian software, and molecular simulations of biodiesel were carried out using LAMMPS. The optimized molecular geometry of biodiesel was obtained via quantum calculations, and structural parameters such as bond lengths, bond angles, and dihedral angles were determined. The electronic structure of the biodiesel molecule was also analyzed. Molecular dynamics (MD) simulations were then employed to investigate structural properties—including density, radial distribution function (RDF), and spatial distribution function (SDF)—as well as dynamic properties such as mean squared displacement (MSD) and diffusion coefficient. The simulated density showed excellent agreement with experimental data, differing by only ~0.03 g/cm³, which validates the reliability of the simulation model. RDF analysis further revealed that the strongest intermolecular interactions in the system occur between the carbonyl (C=O) groups and oxygen atoms.

   Abstract The presence of heavy metals in drinking water has harmful and harmful effects on human health. Iron is one of the metal ions whose amount affects the water quality. The world health organization has stated that the amount of iron in drinking water is 0.3 mg/L. If iron concentration is increased, it will give an unpleasant taste to the water and higher concentrations indicate the presence of industrial effluents and factory wastewaters. In the first part of this research, a simple and selectable colorimetric method was used to measure Fe(II) and Fe(III) ions. In the first work, in order to detect Fe(II) in water samples of different regions, paper colorimetric sensors based on nanocellulose and phenanthroline and also colorimetric sensors in the glass substrate were used.The recorded images of samples were analyzed with Image Analyzer software to abtain RGB indices. Their plotted curve was linear in the concentration range, 1.0×10-5-1.0×10-3 M with detection limit, 8.75×10-6 M. The relative standard deviation of this method was less than 2% and the relative error was less than 20% for all four samples. In the second work, carbon dots were used to reduce Fe(II) to Fe(III) and form red complex. The plotted curve was 1.0×10-5-1.0×10-3 M, and the detection limit was linear 6.5×10-6 M. The relative standard deviation was less than 1.5% and the relative error for Moallem neighborhood water was 9.1%, Chambashir and Taqbostan rivers were 21.4% and 7.7%. Also the proposed method was used to measure the amount of iron in the rock samples. In the first sample, the percentage of iron was 0.11 % and in the second sample was 0.44 %. The relative error was 25% for the first and 3.3% for the second sample. Also the proposed method was used to measure the amount of iron in the rock samples. In the first sample, the percentage of iron was 0.11 % and in the second sample was 0.44 %. The relative error was 25% for the first and 3.3% for the second sample. Sulfite is one of the most common methods of preserving dried foods. In addition to long-term storage, sulfite is also effective in preserving food color. The world health and food and agriculture organization have determined acceptable daily intake of sulfite for adults 0.7 mg/kg body weight and the allowable amount of sulfite in food is 10 ppm. In the second part of this study, the observed color change due to the reduction of   Fe(III) to Fe(II) and formation of red iron(II) complex with phenanthroline were used to identify and measure sulfite. In the first work, a paper sensor was used to detect and measure sulfite in food samples such as plums, apricots and raisins. The recorded images of samples were analyzed with Image Analyzer software to abtain RGB indices. The plotted curve was linear in the concentration ranges of 1.0×10-5-1.0×10-4 M and 3.0×10-4-1.0×10-2 M. The detection limit was 4.5×10-6. The relative standard deviation for all three samples was less than 2% and the relative error for was less than 15 %. In the second work, paper sensor was used to detect sulfite colorimetric in gas phase (sulfur dioxide). Hydrochloric acid was used to form the gas and to prevent the gas from leaving the adhesive tape. After 5 minutes the color change was observed and the rgb digital images recorded from the samples were obtained. The plotted curve 1.0×10-4-1.0×10-1 M linear and the detection limit was 9.0×10-5. The percentage of relative error was less than 10% for the samples.   

  In chapter 1, the growing consumption of conventional fossil fuels and accompanying environmental contamination are affecting global society on an unprecedented scale. Consequently, thereis a quite imminent need to fundamentally adjust the world energy landscape and build clean, low-carbon, safe, and efficient modern energy systems. As an ideal clean chemical fuel with superb gravimetric energy density and energy conversion efficiency, hydrogen energy is expected to be an excellent candidate to replace traditional fossil fuels. Electrochemical water splitting is considered to-be one of the most promising hydrogen production technologies, and it can utilize electricity generated via renewable energy sources, such as solar energy, wind power, geothermal energy, and bioenergy, to form a closed loop of renewable energy. Unfortunately, the large-scale commercial application of electrochemical water splitting is subject to the following three restrictions: (i) a larger overpotential than the theoretical value (1.23 V) needed to drive overall water splitting; (ii) the poor stability of electrode materials; and (iii) high cost caused by the scarcity of noble-metal electrocatalysts. To date, the benchmark electro catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are Pt-group- and Ru/Ir-based noble metal materials with small overpotentials and low Tafel slopes. These noble metals can suffer from dissolution, agglomeration, and poor durability during the water splitting process. The design of electrocatalysts with high electrocatalytic activity is of great importance to reduce the overpotential and improve the efficiency of water decomposition.