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Herein, we report a facile method for the preparation of polypyrrole-multi walled carbon nanotube hybrid material including Pt nanoparticles (Pt@PPy-MWCNT NPs) and the use in methylamine borane (MeAB) for hydrolysis reaction at mild conditions. The prepared catalyst of Pt@PPy-MWCNT NPs was characterized by some advanced analytical methods. The catalytic experiments showed the Pt@PPy-MWCNT NPs can catalyze MeAB in aquatic solution with high catalytical performance at mild conditions. The reaction rate of catalytic hydrolysis with Pt@PPy-MWCNT NPs was found to be -d[CH3NH2BH3]/dt = + d[H2]/3dt = kobs[Pt@PPy-MWCNT]1.19 [MeAB]0.88. The TOF value for the hydrolysis of MeAB catalyzed with Pt@PPy-MWCNT NPs was detected to be 10234.2 1/h (170.57 1/min) which is very high compared with TOF values found for other catalysts. Enthalpy, entropy and activation energy for the hydrolysis of MeAB were calculated to be 31.57 kJ mol−1, −119.97 J mol−1 K and 34.27 kJ mol−1, respectively.

Several metal nanoparticle based catalysts have been synthesized for catalyzing the hydrogen production process by hydrolysis of methylamine-borane (MeAB). However, there was only one study that catalyzes the producing of hydrogen via the methanolysis of MeAB, and it was carried out by our research group. For this reason, in this work, a new catalyst system entitled by single-walled carbon nanotube (SWCNT) supported bimetallic platinum-ruthenium nanoparticles were developed and called as PtRu@SWCNT. These NPs were characterized by several techniques (XRD, XPS, Raman, and TEM), and they were performed for the methanolysis of MeAB with high catalytic activity. The prepared PtRu@SWCNT NPs were also tested in the methanolysis of MeAB at different parameters including different temperatures, catalyst and substrate concentrations, and reusability performance. Experimental results revealed that the new PtRu@SWCNT NPs had excellent catalytic activity and reusability for removing of hydrogen from the methanolysis of MeAB at ambient conditions. According to the obtained data, the turnover frequency is 136.25 mole H2/mole PtRu × min, and the activation energy (Ea) is 17.29 kJ/mole. More than 99% of conversion was observed at room temperature. © 2019, The Author(s)., Kütahya Dumlupınar Üniversitesi, The authors would like to thank Van Yuzuncu Yil (FAP-2018-7373) and Dumlupinar University for funding.

The availability of sustainable and environmentally friendly energy sources is one of the biggest challenges faced by scientists and engineering communities. First of all, the fossil fuels used to meet existing energy demands cause the depletion of resources, the increase of greenhouse gas emissions, and eventually destruction of nature. Polymers have many industrial application areas due to the ease of processing, the reasonable price and the ability to modify with the desired features. Biopolymers have become a focus of attention in terms of the polymer sector because biomass can be separated into harmless products such as CO2 and H2O in the natural environment and can have sustainable resources. The studies on biomass and hydrogen fuel cells are more advantageous than other alternative and clean energy sources because they have the continuous energy supply, compact design, and wide application areas without being dependent on nature. In practice, the polymer electrolyte membrane fuel cells are pinched among the other fuel cells. For this purpose, in this chapter diffusion, transport and water absorption properties of eco-friendly polymer composites generally used are discussed.

In this study, we report a superior dehydrogenation catalyst for dimethylamine borane, which exhibited one of the best catalytic activities. The newly formed catalyst system contains well dispersed ruthenium-copper nanomaterials on reduced graphene oxide (3.86 ± 0.47 nm), which was prepared by using the ultrasonic double reduction technique. The characterization of monodisperse ruthenium-copper alloy nanoparticles was performed using some advanced analytical methods such as TEM, HRTEM, XPS, Raman spectroscopic analysis. The experiments results revealed that the monodisperse ruthenium-copper alloy catalyst (RuCu@rGO) has one of the highest catalytic activity compared to previous studies, having a high turnover frequency value (256.70 h−1). The detailed kinetic parameters such as activation energy, enthalpy, and entropy values were also calculated for the dehydrogenation of dimethylamine borane at room temperature. Also, the results showed that the monodisperse RuCu@rGO catalyst has high durability and reusability as retained its 81% initial catalytic activity even after 4th runs for the dehydrogenation of dimethylamine borane.

In adsorption experiments, enzymes and diatomite clay minerals that have been used lately are of great importance due to their biological and physicochemical properties. For this purpose, in this study, the adsorption and kinetic parameters of lipase enzyme on diatomite clay were investigated. The diatomite and the lipase enzyme were characterized by SEM, TGA, FTIR, etc. The effect of adsorption kinetic parameters such as pH (from 5.5 to 9), initial of enzyme concentration (0.10–0.35 g L−1), temperature (288–318 K), and ionic strength (1.10−3–7.5.10−3 mol L−1) was investigated, and obtained optimum conditions for the maximum adsorption capacity of diatomite clay were found to be pH 7, temperature of 36.5 °C, and ionic strength of 0.35 g L−1. The kinetic data obtained from experimental studies were investigated using different kinetic models that are pseudo-first-order, pseudo-second-order, and intra-particle diffusion. The results showed the second-order equation was found to be the best kinetic model for the adsorption process. The activation parameters such as Ea, enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS) were calculated. The activation parameter results showed that the interaction between diatomite clay and lipase enzyme is a physical interaction and their adsorption process is exothermic. These results indicated that diatomite clay could be used as an adsorbent for the adsorption of lipase on diatomite.

Addressed herein, thiourea functionalized graphene oxide-based PtRu nanocatalysts (PtRu@T/GO) has been synthesized and characterized by several techniques and performed for methanol oxidation reactions as novel catalysts. In this study, graphene oxide (GO) was functionalized with thiourea (T/GO) in order to obtain monothiol functionalized graphene and increase the stability and activity of the nanocatalysts. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), TEM (transmission electron microscopy) and high-resolution transmission electron microscopy (HR-TEM) were used for characterization of the prepared nanocatalysts. The results obtained from these techniques showed that the prepared nanocatalysts were in a highly crystalline form, well dispersed on T/GO, very small in size and colloidally stable. The average size of the synthesized nanocatalysts determined by TEM analysis was found to be 3.86 ± 0.59 nm. With HR-TEM analysis, the atomic lattice fringes of the nanocatalysts were calculated to be 0.23 nm. After the full characterization of the prepared nanocatalysts, they were tried for the methanol oxidation reaction (MOR) and it was observed that 97.3% of the initial performance was maintained even after 1000 cycles while exhibiting great catalytic activity and stability with the help of T/GO. Thus, the arranged nanocatalysts displayed great heterogeneous catalyst characteristics for the methanol oxidation response.

Şen, Fatih (Dumlupınar-Author), Broad-spectrum antibiotics have been widely used in the treatment of many systemic and local infections in humans and animals. Herein, we aimed to determine the synergistic and antagonistic effects of phenylalanine with antibiotics cefoxitin, amoxicillin, vancomycin, lincomycin, and bacitracin against 14 pathogenic bacteria. The effect of antibiotics, either alone or in combination with this biomolecular liquid, was tested using the disk diffusion method against different bacteria. The addition of phenylalanine to antibiotic disks directly affected their antimicrobial activity. All the antibiotics used did not show any antimicrobial activity against Staphylococcus haemolyticus when used alone. However, in combination with phenylalanine, each antibiotic inhibited the growth of S. haemolyticus. The use of this biomolecular liquid together with amoxicillin and vancomycin also increased the antimicrobial activity against Enterococcus durans. The use of phenylalanine in combination with antibiotics also resulted in antagonistic effects on some pathogens. Further, the effects of antibiotics in combination with phenylalanine on different bacterial pathogens were investigated in vitro. Results provide valuable information to further our understanding of the molecular mechanism of action of antibiotics and to improve their efficacy against bacterial pathogens.

The intense demand for alternative energy has led to efforts to find highly efficient and stable electrocatalysts for the methanol oxidation reaction. For this purpose, herein, graphene oxide-based platinum-cobalt nanoparticles (Pt100−xCox@GO NPs) were synthesized in different ratios and the synthesized nanoparticles were used directly as an efficient electrocatalyst for methanol oxidation reaction (MOR). The characterizations for the determination of particle size and surface composition of nanoparticles were performed by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The structure of the catalysts was detected as face-centered cubic and the dispersion of them on graphene oxide was homogenous (distributed narrowly (4.01 ± 0.51 nm)). Cyclic voltammetry (CV) and chronoamperometry (CA) was utilized for testing electrocatalytic activities of all prepared NPs for the methanol oxidation reaction. It was detected that the newly produced NPs were more active and stable than commercially existing Pt(0)/Co nanomaterial in methanol electro-oxidation in acidic media.

PubMed ID: 29772415 In the present study, highly effective and reusable monodisperse ruthenium–nickel (Ru-Ni) nanomaterials supported on poly(N-vinyl-2-pyrrolidone) (Ru-Ni@PVP) were synthesized (3.51 ± 0.38 nm) by a facile sodium-hydroxide-assisted reduction method; Ru and Ni reduction in PVP solution was accomplished. The prepared nanocomposites were characterized by TEM, HRTEM, XRD, and XPS and performed as a catalyst for dehydrocoupling of dimethylamine-borane (DMAB). It was found that Ru-Ni nanomaterials are one of the most active catalysts at low concentrations and temperature for dehydrocoupling of DMAB. This catalyst with its turnover frequency of 458.57 h?1 exhibits one of the best results among all the catalysts prepared in the literature for dehydrocoupling of DMAB. Significantly low Ea value (36.52 ± 3 kJ mol?1) was also found for dehydrocoupling of DMAB. © 2018 Elsevier Inc.

Addressed herein, the hydrolytic dehydrogenation of hydrazine borane (NH4BH3, HB) was reported in acidic media using nitric acid (HNO3) as a catalyst at room conditions. The aqueous hydrazine borane was treated with HNO3 solution in different concentrations to liberate H-2. Besides, kinetic data were collected to idetificate the activation parameters, the effect of temperature, acid and hydrazine borane concentrations on the hydrogen production for the hydrolytic dehydrogenation of hydrazine borane in acidic media. It can be said that the acid catalyzed hydrazine borane system can be regarded as a simple system for hydrogen production. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Demirbaş Özkan (Balikesir Author), Herein, multiwalled carbon nanotube-based Fe3O4 nano-adsorbents (Fe3O4@MWCNT) were synthesized by ultrasonic reduction method. The synthesized nano-adsorbent (Fe3O4@MWCNT) exhibited efficient sonocatalytic activity to remove Maxilon Blue 5G, a textile dye, and present in a cationic form, in aqueous solution under ultrasonic irradiation. The magnetic nano-adsorbent particles were characterized by high-resolution transmission electron microscopy (HR-TEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffraction (XRD). Some important parameters such as nano-adsorbent dosage, solution pH, initial dye and H2O2 concentration, reaction time, ultrasonic power and temperature were tested to determine the optimum conditions for the elimination of Maxilon Blue 5G dye. The reusability results showed that Fe3O4@MWCNT nano-adsorbent has a decrease of about 32.15% in the removal efficiency of Maxilon Blue 5G under ultrasonic irradiation after six times reuse. Additionally, in order to reveal the sufficient kinetic explanation, various experiments were performed at different temperatures and testing three kinetic models like the pseudo-first-order, pseudo-second-order and intraparticle diffusion for removal adsorption process of Maxilon Blue 5G using Fe3O4@MWCNT nano-adsorbent. The experimental kinetic results revealed that the adsorption process of Maxilon Blue 5G in the aquatic mediums using sono-Fenton method was found to be compatible with the intraparticle diffusion. Using kinetic models and studies, some activation parameters like enthalpy, entropy and Gibbs free energy for the adsorption process were calculated. The activation parameters indicated that Fe3O4@MWCNT nano-adsorbent could be used as an effective adsorbent for the removal of Maxilon Blue 5G as a textile dye and the adsorption process of Maxilon Blue 5G with Fe3O4@MWCNT nano-adsorbent is spontaneous.

In this study, a facile ex situ synthesis of a polyaniline-multiwalled carbon nanotube-based Pt nanocatalyst (Pt@PANI-MWCNT) with an average particle size of 3.18 +/- 0.12 nm was performed successfully. The obtained Pt@PANI-MWCNT nanocatalysts were isolated from the solution medium by centrifugation and then were characterized by spectroscopy and microscopy methods. The characterization studies showed that the prepared Pt nanoparticles were formed on PANI-MWCNT surface, and H-2 evolution was obtained by the dehydrogenation of hydrazine-borane in water as a model reaction under room temperature conditions, with the help of the synthesized nanocatalyst. It was observed that the Pt@PANI-MWCNT nanocatalyst had a very high catalytic activity for the hydrolytic dehydrogenation of hydrazine-borane and generated 2.95 mol of H-2 for 1 mol of hydrazine-borane. The initial turn-over frequency (TOFinitial) value of the prepared nanocatalyst for the model reaction at room temperature conditions was found to be 168.5 min(-1). The calculations for the kinetics of the hydrolytic dehydrogenation reaction showed that the hydrazine-borane catalytic reaction kinetics are first order, with respect to the catalyst concentration; several activation parameters, such as entropy (Delta S-#, (app) = -72.11 +/- 3 J/mol K), enthalpy (Delta S-#, (app) = 43.5 +/- 2 kJ/mol) and activation energy (E-a,E- app = 45.5 +/- 2 kJ/mol), of the catalytic reaction with the Pt@PANI-MWCNT nanocatalyst were calculated using these kinetic data. (C) 2019 Elsevier Inc. All rights reserved.

Direct ethanol fuel cells (DEFCs) use ethanol as a fuel to obtain energy in a low temperature. This makes them one of the most important among fuel cells. However, in order to increase the efficiency of these fuel cells, highly effective catalysts should be developed. These catalysts may be of a wide variety of nanoparticles like platinum-based nanoparticles as a most efficient fuel cell catalyst. Generally, the nanoparticles related to the catalyst are obtained using functionalized carbon derivatives. The catalyst obtained in this study shows a higher electrocatalyst activity than the Pt and demonstrates excellent electrocatalytic performance for ethanol oxidation reaction. In this chapter, the reduced graphene oxide was used as a support and a composite material was obtained by synthesizing platinum–ruthenium nanoparticles (PtRu@rGO) with the help of chemical reduction method. The resultant PtRu@rGO nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The electrochemical activity of the catalyst was determined using chronoamperometry (CA) and cyclic voltammetry (CV) techniques for ethanol oxidation reaction. The results showed that the prepared nanocomposite has a high catalytic activity for alcohol oxidation reaction. © 2019, Springer Nature Singapore Pte Ltd.

WOS: 000466552500083, PubMed: 31459802, Herein, we have described uniformly dispersed palladium-nickel nanoparticles furnished on graphene oxide (GO-supported PdNi nanoparticles) as a powerful heterogeneous nanocatalyst for the promotion of Knoevenagel reaction between malononitrile and aromatic aldehydes under mild reaction conditions. The successful characterization of PdNi nanoparticles on the GO surface was shown by X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and TEM. GO-supported PdNi nanoparticles, which are used as highly efficient, stable, and durable catalysts, were used for the first time for the Knoevenagel condensation reaction. The data obtained here showed that the GO-supported PdNi nanocatalyst had a unique catalytic activity and demonstrated that it could be reused five times without a significant decrease in the catalytic performance. The use of this nanocatalyst results in a very short reaction time under mild reaction conditions, high recyclability, excellent catalytic activity, and a straightforward work-up procedure for Knoevenagel condensation of malononitrile and aromatic aldehydes., DPU BAP [2014-05], The authors would like to thank DPU BAP for funding (2014-05).

This book presents emerging economical and environmentally friendly polymer composites that are free of the side effects observed in traditional composites. It focuses on eco-friendly composite materials using granulated cork, a by-product of the cork industry; cellulose pulp from the recycling of paper residues; hemp fibers; and a range of other environmentally friendly materials procured from various sources. The book presents the manufacturing methods, properties and characterization techniques of these eco-friendly composites. The respective chapters address classical and recent aspects of eco-friendly polymer composites and their chemistry, along with practical applications in the biomedical, pharmaceutical, automotive and other sectors. Topics addressed include the fundamentals, processing, properties, practicality, drawbacks and advantages of eco-friendly polymer composites. Featuring contributions by experts in the field with a variety of backgrounds and specialties, the book will appeal to researchers and students in the fields of materials science and environmental science. Moreover, it fills the gap between research work in the laboratory and practical applications in related industries. © Springer Nature Switzerland AG 2019.

In this study, the adsorption of bovine serum albumin with the Turkish Green Clay and its thermodynamic parameters were performed. Experimental studies were done on parameters such as contact time (1–120 min), temperature (298–318 K), pH (5.5–9), and protein concentration (0.025–0.075 g/L), in the applied adsorption process of bovine serum albumin. The adsorption process showed that the intraparticle diffusion mechanism could be said to be more appropriate for the BSA sorption. The maximum adsorption capacity of the green clay mineral was found to be 196.74 mg/g.

In this study, a simple and reproducible production method at room temperature of the monodispersed Pd-Ni nanoparticles supported on activated carbon (AC) was explained. To produce these nanoparticles, a sodium hydroxide-assisted reduction method combined with simultaneous reduction was used that employed no stabilizer. The nanoparticles were characterized by an ultraviolet-visible spectrophotometer, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that Pd-Ni nanoparticles were highly monodispersed on their supporting material (AC), and had an approximate size of 3.55 ± 0.42 nm. For the aim of catalytic decomposition of dimethyl ammonia borane (DMAB) as a safe and convenient hydrogen carrier for fuel cells under mild conditions, the produced activated carbon-supported Pd-Ni nanoparticles were utilized. As a result, the produced NPs catalyzed the DMAB dehydrogenation with high catalytic activity (TOF = 316.41) at room temperature. In addition, Pd-Ni @AC NPs had good stability and no agglomeration; leaching and CO poisoning were observed. The Pd-Ni catalyst carried most (~ 81%) of its own activity after six reuses in the DMAB dehydrogenation at complete conversion. Moreover, the present study shows the kinetic data compilation for the Pd-Ni NPs catalyzed DMAB dehydrogenation and determines the catalytic reaction parameters (Ea, ΔH#, and ΔS#).

In this work, graphene oxide (GO)-supported ruthenium nanomaterials (Ru@GO NPs) were used as catalysts in dimethylamine borane (DMAB) dehydrogenation. Raman spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) have been used for the characterization of prepared nanomaterials. The produced nanomaterials show high efficiency and reusability in addition to very good catalytic activities recorded at low temperatures and at low concentrations for the dehydrogenation of dimethylamine borane (DMAB). Ru@GO NPs have a significantly high turnover frequency (TOF) (410.01 h− 1) and low activation energy (Ea) (44.67 ± 2 kJ mol− 1) for dehydrogenation of DMAB.

Herein, the composite of palladium nanoparticles and graphene oxide (CPG) has been synthesized by a facile and very efficient method that provided chemical selectivity and high catalytic activity. The synthesized CPG was characterized by several techniques such as transmission and high-resolution electron microscopy (TEM and HR-TEM), X-ray diffraction (XRD) and Raman spectroscopy, and Photoelectron spectroscopy (XPS). CPG was tested for selective reduction of nitroarenes at room temperature. After the addition of CPG to the reaction media, catalytic performances were depended upon the cooperative effect of hydrogen activation with Pd nanoparticles, where the lack of electrons favors an excellent performance. Nitroarenes can be bound to the energetically preferred adsorption site for the nitro group in electrically enriched graphene oxide. In addition, the Pd nanoparticles transfer electrons to the graphene oxide which increases the functions of metal and carbon support. CPG exhibits both chemoprotective and high catalytic performance for hydrogenation of nitroarenes at room temperature. Aniline derivatives were obtained with high yields under mild conditions and a practical catalytic system was developed by the use of CPG.