Sharif Digital Repository

The global energy outlook has been altered as a result of mounting concerns regarding fossil fuels. Electrocatalysts have become a favorable alternative for renewable energy production processes, particularly in the fields of hydrogen evolution reactions (HER) and oxygen evolution (OER). This study focuses on the production and enhancement of nanocatalysts, specifically materials based on ZIF-67, for the purpose of water splitting. The initial phase included the synthesis of the ZIF-67 structure through the simple room-temperature coprecipitation process, utilizing cerium as a dual-metal component. The molarity of the cerium was optimized in the ZIF-67 framework to achieve the most desirable... 

In this project, a new magnetically recoverable nanocatalyst was developed by immobilizing of vanadyl acetylacetonate, [VO(acac)2], onto surface of silica coated magnetite nanoparticlest that modified by reaction between 3-aminopropylthriethoxy silane and 5-bromosalicylaldehyde. In the first step, magnetite cores were synthesized by co-precipitation method and coated by tetraethyl orthosilicate (TEOS) and modified by 3-aminopropyltriethoxy silane to provide a precursor for Schiff base condensation reaction. In the next step, amino-functionalized silica coated magnetite nanoparticles were reacted by 5-bromosalicylaldehyde to formation a Schiff base moiety onto surface of magnetite coated... 

In the first part of this research, we have developed a simple and effective ratiometric fluorescence sensor for selective detection of dopamine (DA) in alkaline media by simply mixing thioglycolic acid (TGA) functionalized orange fluorescent cadmium telluride (CdTe) quantum dots (QDs) with amino-functionalized blue fluorescent carbon nanodots (CDs). Under a single excitation wavelength of 365 nm, the sensor exhibits dual-emissions centered at 445 and 603 nm. The fluorescence of CdTe QDs is selectively quenched by DA, whereas the fluorescence of CDs is insensitive to the analyte. In the presence of different amounts of DA, the variations in the dual emission intensity ratios exhibit a... 

Considerable efforts have been directed in recent years towards the transition metal complex catalyzed oxidation of organic compounds. Among these, oxidation of sulfides to sulfoxides and alkenes to epoxides have specially been attended a lot, since sulfoxides and epoxides are important intermediates in organic synthesis. In this study [MoO(O2)(oxazine)2] complex has been synthesized and characterized by FT-IR and 1HNMR. This complex was found to be an efficient, selective catalyst for the oxidation of various sulfides to sulfoxides with urea hydrogen peroxide (UHP) in excellent yields (100% for dioctylsulfide) and short reaction times (20 min) at room temperature. Also this new efficient... 

In this project two manganese(III) complexes with 2-(2',4'-dihydroxyphenyl)-2-oxazoline ligand, [Mn(4-OHphox)3], [Mn(4-OHphox)2(CH3OH)2]ClO4 and a copper(II) complex with 2-(2'-hydroxy)-2-oxazoline ligand have been synthesized. The complexes and the ligands were characterized by elemental analysis (CHN), FT-IR and 1HNMR spectroscopies. Oxidation of sulfides catalyzed by these complexes using urea-hydrogen peroxide (UHP) as oxidant within short reaction times (5 min) was investigated. The results showed that catalytic efficiency of [Mn(4-OHphox)3] complex was better than other complexes. Optimization of the catalyst system presented a high selectivity of sulfoxide (90-100%) in a few time (5... 

In this study new manganese(III) complexes of phox [Mn(phox)2(MeOH)2](ClO4), (phox= 2-(2` hydroxyphenyl)-5,6-dihydro-1,3-oxazine) have been synthesized and characterized with CHN,NMR and IR.The six-membered bidentate (N,O) oxazine ligand have been widely used throughout organometallic and inorganic chemistry, and are particularly important in homogeneous catalysis. The presence of N and O donor sites in oxazines may modify significantly the ligand roles for the variation of steric and electronic properties. Therefore, such systems are worth exploring for new catalytic uses . Catalytic oxidation reactions provide excellent alternatives for the use of stoichiometric reagents like urea... 

In this research, we focus on study and investigation of the role of Tin(IV) Sulfide (SnS2) nanostructured layer as electron transport layer in perovskite and chalcogenide thin film solar cells. For this purpose, SnS2 powder was prepared through hydro/solvo-thermal method, utilizing different ratios of water and ethanol as solvent and various sulfur sources (thioacetamide and thiourea). Afterwards, different solvents were investigated to achieve a stable ink (about one month) with uniform dispersion. After determining the appropriate ink and powder, thin films of SnS2 were prepared employing spin coating, spray pirolysis and laser pulsed deposition (PLD) methods and characterized. With each... 

The selective oxidation of sulfides to sulfoxides is an important method in organic synthesis because sulfoxides are useful synthetic intermediates for the construction of various chemically and biologically significant molecules. To date, the most important method of preparation involves the oxidation of sulfides. Various oxidizing agents are used for this purpose. Oxovanadium(IV)(Salen) and oxovanadium(V)(Salen)Cl were synthesised and screened in the vanadium-catalysed oxidation of sulfides to solfuxides with urea hydrogen peroxide(UHP) as terminal oxidant. Both complexes showed good activity and selectivity trough the catalytic reaction.characterized by elemental analyses, IR, 1H and 13C...