Atenolol tayini için nafion ve çok duvarlı karbon nanotüp kaplı camsı karbon elektrot kullanılarak ultra hassas yöntem geliştirilmesi

Atenolol (Şekil 1), hipertansiyon tedavisinde yaygın olarak kullanılan β-bloker grubunu oluşturan antihipertansif ilaçtır. Bu çalışmada; Tansiyon tedavisinde kullanılan Tensinör ilacının redoks özellikleri, modifiye camsı karbon elektrot ve bu modifiye elektrot üzerine karbon nano tüp kaplanarak hazırlanmış elektrotlarda incelenmiştir. Nafion kaplı çok duvarlı karbon nanotüp (MWCNT/NGCE) elektrot yanıtı ile Nafion kaplı camsı karbon elektrot (NGCE) ve sadece camsı karbon elektrot (GCE) yüzeylerinin elektrot yanıtlarının destek elektroliti, pH, ve tarama hızı üzerine etkilerini araştırmak için Çevrimsel voltametri (CV) ve Diferansiyel puls voltametri (DPV) yöntemleri kullanılmıştır. Atenolol (ATN) Britton-Robinson (BR) tampon çözeltisinde (pH 7.0) 1.11 V (vsAg/AgCl (3.0 mol L-1 KC1) civarında gözlenmiştir. Voltametrik yöntem, optimum analitik deney koşulları altında, 3x10-5 µM -9x10-2 mM konsantrasyon aralığında lineer tepki göstermiştir. Britton-Robinson (BR) (pH=7) tamponundaki Tensinör belirme sınırı sonuçları, sırasıyla 7.67 x 10-5 mM ve 2.5x10-4 mM olarak bulunmuştur. Ayrıca çalışmada ilaçların hazırlanmasında kullanılan yardımcı maddeler ile girişim etkisi deneyleri gerçekleştirilmiş ve olumsuz bir etkiye rastlanmamıştır

Hydrogen production through the cooperation of a catalyst synthesized in ethanol medium and the effect of the plasma

In the present study, nanostructured Ni-B catalysts were successfully prepared in ethanol medium using the chemical reduction method for hydrogen production from the catalytic hydrolysis of sodium borohydride (NaBH4). Ni-B nanostructures were characterized by several analysis methods including XRD, SEM/EDS, FT-IR and BET. The effects of factors such as solution temperature, NaBH4 loadings, catalyst amount and NaOH concentration on the performance of these catalysts in the production of hydrogen from alkaline NaBH4 solutions were investigated in detail. In addition, the Ni-B catalyst prepared in ethanol medium and subjected to plasma for the hydrogen production from the catalytic hydrolysis of NaBH4 was investigated. The Ni-B catalyst prepared in ethanol medium showed maximum hydrogen production rate (1000 mL min-1gcatalyst-1) which was approximately 2 times higher than the rate obtained from the Ni-B catalyst prepared in water (400 mL min-1gcatalyst-1) and acethone (550 mL min-1gcatalyst-1). The Ni-B nanoparticles showed the best catalytic activity at 333 K with a maximum hydrogen production rate of 7134 mL min-1gcatalyst-1 and activation energy of 46.83 kJmol-1 for the NaBH4 hydrolysis reaction in the Ni-B catalysts prepared in ethanol and subjected to plasma. As the Ni-B catalyst is inexpensive and easy to prepare, it is feasible to use this catalyst in the construction of practical fuel cells for portable and in situ applications.BEBA

Hydrogen production by using Ru nanoparticle decorated with Fe3O4@SiO2–NH2 core-shell microspheres

Noble metals are commonly used in order to accelerate the NH3BH3 hydrolysis for H2 production as heterogeneous catalysts. The nanoparticles (NPs) of these metals can be applied as active catalysts in fluid reactions. Metal NPs included in the core-shell nanostructures emerged as well-defined heterogeneous catalysts. Additionally, unsupported NPs catalysts can be gathered easily among neighboring NPs and the separation/recovery of these catalysts are not efficient with traditional methods. For this reason, here, silica-shell configuration was designed which was functionalized with a magnetic core and amine groups and Ru NPs were accumulated on Fe3O4@SiO2–NH2 surface for H2 production from NH3BH3. Fe3O4@SiO2–NH2–Ru catalysts demonstrated high catalytic activity as long as it has a hydrogen production rate of 156381.25 mLgcat−1 min−1 and a turnover frequency (TOF) of 617 molH2molcat−1min−1 towards the hydrolysis dehydrogenation of AB at 30 °C. This result is significantly higher than most of the known catalysts