Nahit AKTAŞ

Article | 2021 | Inorganic Chemistry Communications126

The catalytic effects of metal nanoparticles (MNPs) synthesized in sodium bis(2-ethylhexyl) sulfosuccinate (AOT) microemulsion system by using M(II) salts (M = Fe, Co, Ni) and NaBH4 reducing agent on methylene blue (MB) degradation reaction were investigated. It was determined that Co-MNPs gave the best catalytic activity among them. Influence of the reaction parameters e.g., reaction time, temperature, the size of catalyst and the MNP types on the catalytic performance were studied. It was found that 37 /- 6 nm Co-MNPs revealed the best catalytic activity in all studies. The best activation parameters were calculated as 13.6 /- 1.1 . . . kJ mol(-1) and Delta H = 10.7 /- 1.0 kJ mol(-1) and Delta S = -87.9 /- 5.4 J mol(-1) K-1. The activity ?f Co-MNPs was calculated as 85.4 after 30 days on the shelf life study. The reusability studies were carried out and the activity of Co-MNPs at the 5th reuse was calculated as 70 /- 5?Finally, the catalytic activity of Co-MNPs was investigated inside equal volumes of single and multiple solution mixtures containing MB, 4-Nitrophenol (4-NP) and Eosin Y (EY). In the examinations, it was observed that the nanocatalyst was effective as a reducing agent in all equal amount solutions (MB/4-NP, MB/EY, 4-NP/EY, and MB/4-NP/EY). And also, TOF (mole of MB/4-NP/EY) (mol catalyst.min)(-1) values of catalytic activities were also calculated More less

Nahit AKTAŞ

Article | 2020 | Inorganic Chemistry Communications116

In this study, magnetic metal nanoparticles (MNP) were prepared by using Fe, Co and Ni ions and NaBH4 as reducing agents in oil-in-water microemulsion system. The prepared MNP were used as catalyst in 4-Nitro phenol (4-NP) reduction to 4-Aminophenol (4-AP). It was found that magnetic Co MNP performed superior catalytic performances than Fe and Ni MNP for 4-NP reduction. The catalytic reduction experiments revealed that as the concentration of reducing agent, NaBH4 that was used in the preparation of Co MNP was increased, the complete conversion time for 4-NP to 4-AP was decreased as the sizes of Co MNP were obatined as 75 /- 16, 60 . . ./- 9, and 37 /- 6 nm when using 0.1, 0.2 and 0.4 M NaBH, respectively. Therefore, Co MNP prepared by using 0.4 M NaBH4 was used in the detailed investigation of various parameters such as the effect Co nanoparticles, reaction temperatures and time. The activation parameters of Co nanoparticle prepared by using 0.4 M NaBH4 as reducing agent was calculated as Ea = 32.1 /- 3.1 kJ mot(-1), Delta H = 28.8 /- 2.2 kJ mot(-1 )and Delta S = - 162.5 /- 9.4 J mol(-1) K-1 that is the best catalytic performance amongst the other Co MNP5. The shelf life (storage) studies of Co nanoparticles showed that smaller Co MNP obtained by using 0.4 M NaBH4 reduce catalytic performance faster than the others, e.g, in the order of Co MNP(0.4 M NaBH4) > Co MNP(0.2 M NaBH4) > Co MNP(0.1 M NaBH4) in 20 day storage at ambient temperature. The activity?f Co MNP was decreased to 58 /- 3?fter five consecutives use while maintaining 100?onversion at every use corroborating the promising industry application of this magnetic Co MNP More less

Ali Osman SOLAK

Article | 2020 | Inorganic Chemistry Communications116

Electrochemical and spectroelectrochemical properties of newly synthesized diazonium salt of 2-(2-(1,3-dioxo- 3,3a-dihydro-1H-isoindol-2(7aH)-yl)-1-(3 methyl-3-phenylcyclobutyl)ethylidene) hydrazinecarboxamide (DDPHC-DAS) were studied using glassy carbon (GC) electrode. In the current study, surface characterization was performed by cyclic voltammetry (CV). Besides electrochemical impedance spectroscopy (EIS) was used for the electrochemical and spectroelectrochemical characterization. Surface images were obtained using scanning electron microscopy (SEM). After completion of modification and characterization process, DDPHC-DAS surfa . . .ce was examined for the usability for the quantitative determination of phenol and chlorophenol derivatives by using CV, square wave voltammetry (SWV) and differential pulse voltammetry (DPV). Phenol and chlorophenol solutions that were prepared in Britton-Robinson (BR) buffer solution (pH 8-12) were employed in this research. The presented study proves that all of compounds can be quantitatively determined not only simultaneously but also independently More less