Open Access Original Research Article

Size Effects of Silver Nanoparticles on the Photovoltaic Performance of Dye Sensitized Solar Cells

M. Y. Onimisi, Danladi Eli, S. G. Abdu, H. O. Aboh, Ezeoke Jonathan

Chemical Science International Journal, Page 1-8
DOI: 10.9734/ACSJ/2016/24525

Solar Cells

The size effects of silver (Ag) nanoparticles (NPs) on the performance of a dye sensitized solar cells (DSSCs) through successive ion layer adsorption and reaction (SILAR) was investigated. A series of AgNPs with different SILAR cycles were synthesized on fluorine tin oxide (FTO) glass slides. The size effects of AgNPs on the photovoltaic (PV) performance of the formed DSSCs were investigated systematically. The performance, especially the photocurrent, and open circuit voltage of DSSCs containing AgNPs was significantly affected by the particle size of Ag NPs. The PV performance decreased with increasing size of AgNPs from one SILAR cycle to three SILAR cycles, the best performance was achieved using the anodes prepared with one SILAR cycle. The best cell shows a conversion efficiency (η) of 0.00910%. The cell exhibited a 36% improvement over the performance (0.00669%) of bare FTO-based device. The related PV performance enhancement mechanism and surface-plasmon resonances in DSSCs with Ag nanostructures are discussed.

Open Access Original Research Article

Phytochemical Screening and Antimicrobial Activity of Ficus sycomorus Extracts of the Stem Bark and Leaves on Some Pathogenic Microorganisms

Adamu Suleiman Ahmad, Abdulhamid Dahiru, Abba Tijjani Muhammad, Hamza Idris, Kamlish Gautam

Chemical Science International Journal, Page 1-5
DOI: 10.9734/ACSJ/2016/23654

The preliminary of Phytochemical screening of methanol and ethanol extracts for both the stem-bark and leaves of Ficus sycomorous revealed the presence of flavonoids, glycosides, reducing sugar, resins, tannins and saponins. The result of anti-microbial activity indicates that ethanol and methanol extracts of both stem-bark and leaves show a remarkable activity on gram positive bacteria of Staphylococcus aureus more than the gram negative bacteria of Salmonella typhi. Also the extraction shows that the stem bark and leaves extract of ethanol yield 29·86% and 40.07% respectively in ethanol compared to methanol extract which yield 13.93% and 14.72%  for the stem bark and leaves extract respectively.

Open Access Original Research Article

Geometric and Electronic Structure of Papaverine and Its Acid Strength

V. A. Babkin, V. Yu Dmitriev, D. S. Andreev, L. M. Lisina, A. I. Rakhimov, N. A. Rakhimova, V. S. Belousova, O. A. Ponomarev, G. E. Zaikov, O. V. Stoyanov

Chemical Science International Journal, Page 1-8
DOI: 10.9734/ACSJ/2016/22405

For the first time ever, the quantum-chemical calculation of papaverine molecule was performed within the framework of molecular model by methods RHF/6-311G** and DFT-PBE0/6-311G**. Optimized geometric and electronic structure of this compound was obtained. Its acid strength was also theoretically estimated. It was proved that papaverine molecule belongs to the class of very weak acids (pKa>14). It was shown that 3.4-di(methoxy)benzyl  group is the electron-donating substituent. It is revealed, that dimethoxy-group and 3.4-di(methoxy)benzyl  group influence on the distribution of electronic density and pKa value.

Open Access Original Research Article

Determination of Nitrate and Nitrite Contents of Some Edible Vegetables in Guyuk Local Government Area of Adamawa State, Nigeria

Priscilla Alexander, Philemon Handawa, Umoru Titus Charles

Chemical Science International Journal, Page 1-7
DOI: 10.9734/ACSJ/2016/23387

Based on research founding’s nitrite and nitrate has been discovered as pro-drugs of the vasorelaxant nitric oxide, however many studies have reported that intake of these ions either intravenously or as a food supplements enhanced athletic performance. One of the factors and major causes of gastrointestinal cancer in adults and Methemoglobinemia (blue baby syndrome) in children is nitrosamine derived from nitrate. Approximately 80 to 90 percent of nitrate which enters the human body is through vegetables and fruits, in this present study nitrate and nitrite concentrations in fresh leafy and fruits vegetables in Guyuk was determined and compared with WHO standard limit. The levels of nitrate and nitrite were determined in six edible vegetable samples consumed and cultivated in Guyuk Local Government area of Adamawa State, Nigeria. The vegetables studied were Spinacea oleracea (spinach), Amaranthus caudatus (Amaranthus), Lycopersicum esculentum (Tomato), Allium cepa (onion), Abelmoschus esculent (Okra), and Brassica oleracea (Cabbage). The nitrate and nitrite concentrations were analyzed by ultraviolet spectrophotometer method. The results of the present investigation showed no any significant difference in nitrate levels found in most vegetables cultivated during the dry and rainy season harvests. Statistically, the mean nitrates level was higher in spinach (52.50±4.00 mg/kg to 53.50±4.50 mg/kg), Amaranthus (43.50±3.50 mg/kg to 47.50±2.50 mg/kg), Okra (39.00±2.10 mg/kg to 40.50±0.90 mg/kg) and onion (37.50±0.40 mg/kg to 39.00±1.60 mg/kg), intermediate in tomato (34.50±2.40 mg/kg to 36.50±2.40 mg/ kg), and lower in cabbage (15.00±1.60 mg/kg to 20.50±1.50 mg /kg), as compared with those in other vegetables. However, it was discovered that the level of nitrate in all the edible studied vegetable samples was lower than the WHO standard limit. The concentration of nitrite in the different studied vegetables exceeded 1.0 mg/ kg, but is within the permissible limit of the WHO Standard limit. It was observed that the values have no significant difference among most vegetables. It was also noted that nitrate contents in the studied vegetables differs, depending on the kinds of vegetables and were comparable and similar to those vegetables grown and cultivated in other countries.

Open Access Original Research Article

Effect of Sodium Hydroxide Thickener on Grease Production

K. Ebisike, B. E. Attah Daniel, M. N. Anakaa, H. M. Kefas, S. O. O. Olusunle

Chemical Science International Journal, Page 1-8
DOI: 10.9734/ACSJ/2016/20624

Sodium hydroxide (NaOH) was used to produce grease from spent engine oil. A study of the unworked penetration, viscosity, and dropping point of the grease were analyzed under different temperature ranges, from 30°C to 60°C.

The grease produced was of Brown colour on physical observation. The viscosity decreased at increased temperature with its minimum viscosity being 340.2 and maximum viscosity 590.0. The penetration point also increase as temperature increased and the minimum penetration was found to be 255.0 (in 10-1 mm) and maximum penetration was 415.2 (in 10-1 mm). The dropping point test showed an increase with increase in temperature. The minimum dropping point was 177.4°C while the maximum dropping point was 239.3°C. An increase of temperature up to 40°C shows the consistency number for the grease to be within most commercially available grease grade  i.e. within grade 2 and 3 in the market, hence, the grease produced shows good quality for application within working temperature of between 30°C and  40°C.

Open Access Original Research Article

Micro, Sono, Photocatalytic Degradation of Eosin B Using Ferric Oxide Doped with Cobalt

Abeer Sharfalddin, Eman Alzahrani, Mohamad Alamoudi

Chemical Science International Journal, Page 1-13
DOI: 10.9734/ACSJ/2016/23648

Eosin B dye is usually used for staining in biology; the stain is harmful if swallowed, smelt, or absorbed through skin. Some researchers have tried to remove it by adsorption, but few have attempted for a complete degradation. In this study, cobalt doped iron oxide (Co-Fe2O3) powders were used to decompose eosin B in a solution. The nanoparticles of Co-Fe2O3 were successfully prepared using microwave-hydrothermal process and characterized using different techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive analysis of X-ray spectroscopy (EDAX), and X ray diffraction analysis (XRD). The images obtained from SEM and TEM analysis revealed that grain size is homogeneous and agglomeration with average size range of about 36.97 nm. A new peak was found in EDAX analysis, which confirmed the presence of Co atom with atomic percentage dopant of nearly 5.73%. The crystal size was 50 nm, calculated by XRD analysis data. The photocatalytic activity was evaluated by the degradation of eosin B under microwave, photocatalytic, soncatalytic, and sonophotocatalytic reactions. The degradation percentages were 78, 82, 83 and 87%, respectively. Thus, sonophotolysis was the optimum method to decompose the dye in solution by this method. In addition, the effects of the pH of solution were obviously examined, and it was found that low pH was a suitable pH for degradation eosin B. The photocatalyst could be reused three times without remarkable loss of its activity.