نشریه شیمی کاربردی روز
پیاپی 28 (پاییز 1392)

The photocatalytic water splitting using photon and a semiconductor is a new method for hydrogen production. In this research، photocatalytic hydrogen production using Pt (0. 75wt) /TiO2 photocatalyst has been studied. This nanoparticle was synthesized using sol-gel method. Photochemical deposition method was used for Pt loading. The effect of Pt as a co-catalyst and methanol as a sacrificial agent were investigated. This nanophotocatalyst was characterized using XRD، DRS، BET and ICP methods. The results show that Pt and methanol have positive effect on hydrogen production. Using this nano photocatalyst، the rate of hydrogen production is 87 mL (h g catal.) -1 in the first 3h of irradiation that is about 43 times more than that of the P25 photocatalyst.

The UV-visible spectrum of some different chalkons with both electron with-drawing and electron-donating groups have been investigated. The results showed that electron with-drawing groups cause Blue-Shift and electron-donating groups cause Red-Shift. Fortunately there is a direct relation between the force of electron with-drawing groups and blue shift values، also for electron-donating groups and corresponding red shift.

In this paper two methods were used for the preparation of bis phenols with cardo-group and their polyesters. In comparison with other methods، a suitable method has been proposed for the preparation of these bis phenol s with higher yield and purity and also synthesis of their polymers. To achieve this goal، the 1، 1-bis (4-hydroxyphenyl) cyclohexan was used. In the first method، phenol with cyclohexanone in condensation reaction in the presence of 2 - mercapto propionic acid (the first time) and hydrochloric/acetic acid used. First method gave higher efficiency in comparison to the second method، phenol with cyclohexanone in reflux situation in the presence of hydrochloric/acetic acid was used. Following the identification of bisphenol as a base monomer reacted with terephthaloyl dichloride as new method، solution and the phase transition polymerization. Compounds were identified by IR، NMR، CHNS and polymers were obtained by TGA test.

Anthocyanin is known as natural pigments of fruits. These pigments are among the best natural pigments to be used in food industry. In this study، the method for extraction of cherry’s pigment (Anthocyanin) using an Amberlite XAD-7 resin is discussed. Amberlite XAD-7 has got an excellent condition for extraction of Anthocyanin due to its lack of charged groups and great porosity. After completion of adsorption process of Anthocyanin on Amberlite resin، desorption process was performed by acidic methanol which was able to extract about 90 percent of Anthocyanin compounds. Furthermore، Langmuir and Freundlich isotherms were applied for explanation of Anthocyanin adsorption which finally indicated that Langmuir model has a better consistency

The nanostructured silicoaluminophosphate، SAPO-34، was reported to be the most promising catalyst. It is well-recognized that template plays important roles in the synthesis of molecular sieves. In this research، TEA and morpholine mixtures as organic templates were employed in synthesis of nanostructured SAPO-34 molecular sieve. To correlate the modification of the catalysts features with their performances in MTO reaction، characterizations by XRD، FESEM، PSD، BET، EDX and FTIR techniques were performed. Physiochemical properties of the catalyst were affected by the type of the used templates. The catalyst synthesized with 75% TEA and 25% morpholine showed rhombohedral shape of typical SAPO-34 and also hexagonal type crystal which is typical SAPO-5 morphology. XRD patterns afforded additional support for the obtained results from FESEM images showed diffraction peaks of both SAPO-5 and SAPO-34. Performance tests were carried out to investigate the influence of different temperatures on the catalyst activity in a range of 300-500ºC. The catalysts prepared with morpholine and TEA mixtures showed relatively the same product distribution with regard to light olefins selectivity in the MTO reaction

Theoretical studies on the geometrical parameters، hydrogen bonding and electronic properties of enamine ligand containing pyran cycle [C19H19O7N] and molybdenum bi-nuclear complex [C40H44Mo2N2O20] were investigated using Hartree-fock (HF) and density functional theory (DFT) methods. These calculations were performed with the B3LYP، BPV86، B3PW91 and HF theoretical methods using the 6-311G، 6-311G**، 6-311++G** and LanL2DZ basis sets. To estimate the error rate between theoretical data and experimental data، RSquare and SError values were that according with the theoretical and experimental parameters found out DFT methods has more integration with experimental data compare to HF methods. In addition، through electron specification of compounds، the percentage of atomic orbital’s attendance in making molecular orbital’s، atoms electrical charge، the sustainable energy resulting of hydrogen bonding and also HOMO and LUMO orbital’s energy achieved.

Theoretical studies on the geometrical parameters، hydrogen bonding and electronic properties of enamine ligand containing pyran cycle [C19H19O7N] and molybdenum bi-nuclear complex [C40H44Mo2N2O20] were investigated using Hartree-fock (HF) and density functional theory (DFT) methods. These calculations were performed with the B3LYP، BPV86، B3PW91 and HF theoretical methods using the 6-311G، 6-311G**، 6-311++G** and LanL2DZ basis sets. To estimate the error rate between theoretical data and experimental data، RSquare and SError values were that according with the theoretical and experimental parameters found out DFT methods has more integration with experimental data compare to HF methods. In addition، through electron specification of compounds، the percentage of atomic orbital’s attendance in making molecular orbital’s، atoms electrical charge، the sustainable energy resulting of hydrogen bonding and also HOMO and LUMO orbital’s energy achieved.

Nowadays، Dye sensitized solar cells (DSSCs) emerged as a new class of low cost solar cells that affordable to convert light energy into electrical energy and also they are known as the third generation of solar cells founded on nano structured thin films. Titanium dioxide usually plays as the semiconductor for transmission of excited electrons from dye to the counter electrode (cathode). During one cycle of electron transfer، which electrolyte plays an important role in the electron transportation، electrons will return to the excited dye molecules. This phenomenon practically presents the sunlight conversion into electricity by solar cells. In this project eggplant was used as a natural source of dye for fabrication of DSSC. Dye extraction was performed by suitable solvent and its purification was conducted by Solid Phase Extraction columns. The electrochemical evaluation and final efficiency measurement of fabricated cells were carried out by Electrochemical Impedance Spectroscopy method which is well known as a powerful and non destructive technique in studying of charge transfer on the surface of nano structured electrodes.

Heavy metals in the water resources are one of the most important environmental problems of human societies. Up to now، various methods were considered for removal of heavy metals، which among them using of low cost adsorbents are more favorite but، separation of them from process is so difficult. In this study a novel magnetic adsorbent based on orange peel and iron oxides composite was synthesized and used for removal of cadmium ions from aqueous solution. Dry orange peels were milled and granulated in 0. 125-0. 250 mm by standard sieves. Magnetic iron oxide particles was separately synthesized and allowed to combine with granulated orange peels. Batch equilibrium absorption experiments were carried out at various initial Cd ion concentrations، contact times and adsorption dosages in constant temperature and pHzpc. At the end of each adsorption experiment، the separation of adsorbents from aqueous solution was performed by a magnetic bar. The results showed the magnetic orange peel iron oxide adsorbents had a high efficiency for adsorption of cadmium from aqueous solutions. The experimental adsorption isotherm of cadmium on magnetic orange peel adsorbents were determined and correlated with common isotherm equations such as Langmuir، Freundlich and Temkin models. The results indicated the Freundlich isotherm model was the best model for fitting the adsorption data.