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In this study, cryptomelane-type (1D) MnO2 was doped with boron powder by ball-milling in an inert organic solvent under various experimental conditions. The structural, thermal, morphological, and surface features of samples prepared by the ball-milling method were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy, and surface measurements. The electrocatalytic oxygen evolution reaction (OER) performances of the samples were tested and compared with the bare cryptomelane to reveal the effect of boron doping into manganese oxide. It was found that boron particles transformed to trigonal BO3 units in the cryptomelane structure via mechanical activation, and accordingly, the oxidation state of manganese in this structure relatively changed. The 0.25% B-doped cryptomelane sample prepared at 12 h grinding time exhibited the overpotential of 425 mV at a current density of 1 mAcm(-2) with a Tafel slope of similar to 95 mV dec(-1). It showed a remarkable catalytic performance among the other electrocatalysts under neutral pH compared to bare cryptomelane. When the elemental boron doping exceeded 1%, the electrochemical performance dramatically decreased depending on the blocking of the Mn3+ active sites. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The development of electrocatalysts for the OER (oxygen evolution reaction) process is an ongoing challenge in producing sustainable energy systems. Herein, we report QS (quasi-spherical), IR (irregular), and NR (nanorod) Mn2OBO3 (manganese oxoborate), modified with a carbon support, as candidate electrocatalysts for OER in a neutral medium. QS-, IR- and NR-Mn2OBO3 catalysts displayed low onset potentials of 201 mV, 205 mV, and 208 mV and Tafel slope results of 94 mV dec(-1), 97 mV dec(-1), and 106 mV dec(-1), respectively. As a result of the long-term stability tests, it was determined that the NR-Mn2OBO3 sample was extremely stable compared to the QS- and IR-catalysts. This work introduces a new Mn2OBO3/C composite catalyst that displays efficient OER performance at a neutral medium and provides a different perspective for catalyst development strategies. TENMAK-National Boron Research Institute [2018-30-06-30-005] This work was supported by TENMAK-National Boron Research Institute under grant code: 2018-30-06-30-005. WOS:000706309700001 2-s2.0-85116886154

This study examines manganese oxoborate synthesis in three different routes and the role of process parameters on structure and morphology of the products. Borax or boric acid and simple manganese salts were used as raw materials. In this regard, the samples prepared by hydrothermal, solid-state, and solution combustion methods were characterized by powder X-ray diffraction (XRD), vibrational spectroscopy (FT-IR and Raman), thermal analysis (DSC and TGA), scanning and transmission electron microscopy (SEM and TEM), chemical analysis and BET surface area measurements. It was found that all three strategies yielded warwickite-type Mn2OBO3 nanoparticles, but with significant changes in morphology, size, and surface characteristics. The hydrothermal approach has proven to be a general approach for synthesizing manganese oxoborate nanorods at pH 7.5. Solution combustion technique appeared the most practical and promising not only as a time-saving route but also in the production of ca. 100 nm, quasi-spherical, mesoporous manganese oxoborate nanoparticles. TENMAK-National Boron Research Institute, Turkey [2018-30-06-30-005] We gratefully acknowledge the financial and technical support provided by TENMAK-National Boron Research Institute, Turkey (grant number: 2018-30-06-30-005). WOS:000648613400007 2-s2.0-85102455292

The removal of bisphenol-A (BPA) from the aqueous environment is a vital issue for public health due to its toxic effect. In this work, variable amounts of the dextran coated-magnetite doped metal–organic framework nanocomposites (MOF:Fe3O4@Dex) were successfully prepared and used as an adsorbent for the removal of BPA from aqueous solution. Firstly, dextran-coated magnetite nanoparticles (Fe3O4@Dex) were synthesized via the co-precipitation method, and then MIL-100(Fe) nanocomposites (MOF:Fe3O4@Dex), including different amounts of Fe3O4@Dex nanoparticles, were prepared by the reflux method. The obtained nanocomposites were characterized through Fourier transform infrared spectroscopy, powder X-ray diffraction, thermogravimetric analysis, scanning and transmission electron microscopy, and magnetic and surface measurements. The batch adsorption method was carried out as a function of pH, adsorbent amount, contact time, and initial BPA concentration for the removal of BPA using the MOF:Fe3O4@Dex nanocomposite. The adsorption of BPA could be completed within approximately 60 min at room temperature using 300 mg L−1, 100 mL, pH 5 BPA solution. The maximum adsorption capacity of BPA on the MOF:Fe3O4@Dex nanocomposite was calculated as 347 mg g−1, which is quite a high value compared to that of the previously reported adsorbents. After five cycles, the adsorption capacity of the MOF:Fe3O4@Dex nanocomposite was still retained at a high level. The adsorption kinetics, isotherms, and mechanisms were also investigated. All the results proved that the magnetic nanocomposite (MOF:Fe3O4@Dex) could be a potential candidate for water purification applications.

The new borophosphates were successfully synthesized by solution combustion synthesis assisted with glycine. The obtained materials were systematically characterized by Fourier-transform infrared spectroscopy, X-ray powder diffraction, UV–visible spectroscopy, thermogravimetric analysis, scanning electron microscopy, Brauner-Emmett-Teller surface area, and magnetometry. The Rietveld refinements indicated that Fe2B(PO4)3 is a hexagonal, space group P63/m with a = b = 8.029 and c = 7.408. As Cr substitutes the Fe atoms, there is a significant decrease in the lattice parameters. When all Fe atoms are replaced by Cr, Cr2B(PO4)3 is formed and the structure turns out to be a trigonal, space group P3 with a = b = 7.950 and c = 7.360. The materials are thermally stable and demonstrate paramagnetic behavior at room temperature. The magnetization increases as the iron content increases because of the high magnetic moment of the iron ion. Temperature-dependent magnetic measurements reveal that Fe2B(PO4)3 has a Neel transition at 30 K and the Neel temperature decreases with Cr substitution.

Finding new catalysts and improving the characteristics of existing catalysts are major research issues for boosting dye degradation efficiency. For this purpose, iron vanadates have been prepared by the solution combustion method using oxalyldihydrazide (ODH) and glycine (GLY) as fuel. The surface properties of catalysts were altered, and the degradation efficiency of methylene blue (MB) was improved, depending on the synthesis process and fuel type. When the ODH-assisted FeVO4 has irregular morphology, the GLY-assisted FeVO4 has 100–200-nm uniform nanoparticles with a surface area of 21.96 g/m2 and it is performed as an excellent heterogeneous nanocatalyst for Fenton-like degradation of MB using H2O2 under sunlight. The narrow bandgap allows the adsorption of light and enhances photocatalytic activity. After the optimization of the catalyst amount, H2O2 concentration, and degradation time, the degradation efficiency of MB was found to be nearly 100% with high reusability. The process has a high-rate constant of 0.0304 min−1 and the possible reaction mechanism has been proposed using GC–MS. The GLY-assisted FeVO4 can be a potentially powerful and reusable heterogeneous catalyst for the other contaminants.

This work presents the Fenton-type aqueous-phase oxidation of phenol with two MIL-100(Fe) catalysts prepared by hydrothermal and reflux methods. The catalysts were systematically characterized by infrared spectroscopy, X-ray powder diffraction, thermogravimetry, scanning electron microscopy, and surface analysis techniques. The influence of various experimental parameters on the course of the oxidation process conducted at room temperature was examined. The catalysts showed significant stability when phenol/H2O2 = 1:1 molar ratio was applied. In this case, 93% conversion was obtained with minimal iron leaching (ca. 0.2%). The hydrothermally prepared MIL-100(Fe) catalyst displayed higher catalytic activity due to its larger surface area. The results were also discussed to evaluate the “dark-Fenton” contribution of the system in “photo-Fenton” reactions previously reported with similar catalysts for phenol oxidation. This study has demonstrated that dark-Fenton reaction with MIL-100(Fe) catalysts has an important contribution to the mineralization of phenol without requiring irradiation or ZnO assistance. A schematic illustration of the fabrication processes of MIL-100(Fe) catalysts and their use in Fenton-type phenol oxidation reaction.

For the removal of toxic organic phenol pollutants, to find a new alternative oxidation catalyst has been an important topic for a long time. Iron terephthalate (MIL-53) is an efficient catalyst for oxidation processes with high porosity and high surface area. In this study, MIL-53 was used for the oxidation of phenol. The catalyst was synthesized by hydrothermal method at 150°C for 2 h. It was structurally characterized by FT-IR and p-XRD. Thermal properties were also examined. The surface area was found as 152 m2 /g with micropore areas. The liquid phase oxidation of phenol by hydrogen peroxide was performed on MIL-53. The reaction time, reaction temperature, catalyst amount and oxidant amount were also investigated. The phenol was removed with 91% conversion for 3 hours at 80°C. MIL-53 was enhanced as an alternative catalyst for liquid phase oxidation of phenol with high efficiency, selectivity, and conversion.

In this study, iron oxyborate (Fe3BO6 was synthesized through the solution combustion method as a potential anode material for lithium-ion batteries. Urea, glycine, citric acid, carbohydrazide, hexamethylene tetramine, and starch were used as fuel sources and the effects of the fuels were investigated. The obtained materials were structurally characterized by FT-IR, powder-XRD, solid UV-Vis, TGA and VSM. The pure crystalline Fe3BO6 was synthesized at low temperature and short reaction time using glycine-assisted solution combustion method. It was thermally stable up to 945 °C with a non-uniform morphology and a highly porous structure. The magnetic properties were also studied and Fe3BO6 shows antiferromagnetic behavior. © 2019, Turkish Chemical Society. All rights reserved.

In this study, titanium dioxide was synthesized via solution combustion method. Titanium(IV) oxysulfate was used as a titanium source. The fuel type, reaction time, and reaction temperature were tested for optimization. The glycine was set as a suitable fuel. Structural properties of the final product were characterized by p-XRD. Scanning electron microscopy (SEM) and BET techniques were used to examine the morphology. The synthesized products were compared to the commercial TiO$_{2}$ and it was found that the titanium dioxide with the high surface area (63.628 m$^{2}$/g) has been successfully synthesized by solution combustion method with time and energy saving. In the second part of the study, the adsorption efficiencies of synthesized titanium dioxide were tested, removal of Cr(VI) from wastewater was carried out. It was found that titanium dioxide obtained via solution combustion method has a better capacity for Cr(VI) removal from wastewater than commercial titanium dioxide. In consequence, the chosen synthesis method modified the surface properties and improved the chromium adsorption capacity.

Lithium copper pyrophosphate has been synthesized by the solution combustion method for the first time. Urea and hexamethylenetetramine were used as fuel. The samples were successfully prepared in low reaction temperature and short reaction time. The products were structurally characterized by FT-IR and p-XRD. Thermal behavior of samples was also investigated through TG/DT analyses. Magnetic measurements showed that the urea- and hexamethylenetetramine-assisted Li2CuP2O7 were paramagnetic at room temperature. Surface analyses indicated that the fuel types changed the surface properties of samples because of exothermic redox reaction during combustion, and electrochemical performances showed clear differences. The charge capacity of urea- and hexamethylenetetramine-assisted synthesized Li2CuP2O7 was calculated as 180 mAhg−1 and 146 mAhg−1. Synthesis method enlarged the charge capacity and prepared lithium copper pyrophosphate to have a potential for use in lithium-ion batteries.

Mechanochemistry has gained significant interest as a powerful, more sustainable, timesaving, environmentally friendly, and more economical synthesis method to prepare new functional materials. This method depends on the chemical and physicochemical transformations through mechanical force forming by grinding and milling. This study is a systematic review of the history, principles, mechanisms, and kinetics of mechanochemistry. The effects of mechanochemical synthesis parameters (milling types, materials, size, time, temperature, atmosphere, revolution speed, frequency, ball/powder weight ratio, filling ratio, process control agents) were detailed explained. The current researches about the mechanochemical synthesis of co-crystals, inorganic materials, metal–organic frameworks, porous organic materials, and polymers, their respective characteristics, challenges, and future improvements were briefly discussed.

Two mixed ligand complexes containing acesulfame (acs) and 3-aminopyridine (3-ap) ligands of Mn(II) and Co(II) were synthesized. The obtained compounds were characterized by various analysis methods. The geometries of complexes, C18H28MnN6O12S2 (1) and C18H32CoN6O14S2 (2), are distorted octahedra. Coordination of metal cations is provided by two molecules of 3-ap and four water ligands. In both structures, the 2+ charge of the metal required two monoanionic acs molecules located outside the coordination sphere. Complex 1 contains no hydrate water, while 2 contains two molecules of hydrate water. The crystal system of 1 is monoclinic and space group P2(1)/c, while the crystal system of 2 is triclinic and space group P-1. Data on the removal of hydrate and crystalline waters in structures from thermal analysis curves support the described molecular structures. The bending vibrations of the bonds obtained from the FT-IR spectra match the crystal structure described. As a result of thermal analysis of both complexes, it was determined that the relevant metal cations remained in the reaction vessel as oxide (MnO and CoO) residues. WOS:000626933900001 2-s2.0-85102252527

Cathodes for lithium-ion batteries (LIBs) present stability and performance issues; therefore, searching for alternative novel electrode materials or modifications of known ones is one of the main issues. Warwickite-type Mn2OBO3 samples synthesized by hydrothermal (HT), solid-state (SS), and solution combustion (SC) methods were investigated for the first time as cathode materials for LIBs. The prepared Mn2OBO3 electrodes were analyzed using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in order to correlate the surface properties and electrochemical behaviour. X-ray photoelectron spectroscopy (XPS) revealed the existence of +2 and + 3 oxidation states of Mn in the electrodes. The band gaps (Eg) for all electrodes were calculated between 1.75 and 2.04 eV. The electrochemical performance of the Mn2OBO3 electrodes (E) prepared with the SC method was significantly improved. The E-SC electrode showed the highest initial discharge capacity of about 155 mAhg-1 and found to be more stable at a current density of 30 mAg-1. The results presented here provide a new approach to the utilization of manganese oxoborate compounds as promising cathode materials for high-performance energy storage systems and emphasize that homogeneously structured cathode electrodes with a high surface area are desirable for LIBs. © 2021 Elsevier Ltd and Techna Group S.r.l. Ulusal Bor Araştırma Enstitüsü, BOREN: 2018-30-06-30-005 This work was supported by TENMAK- National Boron Research Institute, Turkey under grant code: 2018-30-06-30-005 . This work was supported by TENMAK-National Boron Research Institute, Turkey under grant code: 2018-30-06-30-005. 2-s2.0-85115769232

© 2021 Elsevier B.V.Novel tetrahydrocarbazole and carbazole-based chemosensors have been synthesized, and their interactions with various anions (F¯, Cl¯, Br¯, I¯, AcO¯, CN¯, H2PO4¯, NO3¯, ClO4¯, and HSO4¯) have been investigated in organic and aqueous environments. As a result of the reversibility studies and 1H NMR experiments, it has been determined that the interaction mechanisms are di-deprotonation. Moreover, chemosensors can be used successfully to determine CN¯ and OH¯ anions in an aqueous medium. Experimental studies were supported with density functional theory calculations.

Using two different synthesis methods, two diversified magnesium and calcium complexes were successfully prepared. When the ion exchange method was used, C9H14MgO11.H2O and C18H30Ca3O24 complexes were obtained. When the one-pot self-assembly reaction was used, C18H34Mg3O26.4H2O and C9H12CaO10 complexes were produced. The structural characterizations were performed by using X-ray diffraction, FT-IR and elemental analyses. Thermal behavior of complexes were also determined via TGA method. The both complexes of magnesium and calcium trimesate have micro and mesoporosity with low porosity because of hydrogen bonds. Then hydrogen storage capacities of complexes were also determined. The differences in synthesis method result in the differences on complexes structure, morphology (shape, particle size and specific surface area) and hydrogen storage capacities. © 2017 Elsevier B.V.

The new metal-organic framework materials based on boric acid reported herein. Sodium and boron containing metal-organic frameworks were synthesized by one-pot self-assembly reaction in the presence of trimesic acid and terephthalic acid in water/ethanol solution. Boric acid is a relatively cheap boron source and boric acid mediated metal-organic framework prepared mild conditions compared to the other boron source based metal-organic framework. The synthesized compounds were characterized by FT-IR, p-XRD, TGA/DTA, elemental analysis, 13C-MAS NMR, 11B-NMR and single crystal measurements. The molecular formulas of compounds were estimated as C18H33B2Na5O28 and C8H24B2Na2O17 according to the structural analysis. The obtained complexes were thermally stable. Surface properties of inorganic polymer complexes were investigated by BET analyses and hydrogen storage properties of compound were also calculated. © 2017 Elsevier B.V.

This study illustrates for the first time the performance of nano-manganese ferrite supported-manganese oxide catalyst in benzyl alcohol (BzOH) oxidation without employing any oxidizing agent other than the air present in the reactor. The magnetic catalyst displayed moderate activity but 100% selectivity in conversion to benzaldehyde (BzH) under mild conditions. Compared to the other heterogeneous MnO x -based systems, the catalyst deserves attention in that an enhancement of the activity can be achieved by tuning the core-shell composition which plays a synergistic role in the catalytic reaction.

The salt type mixed ligand metal complexes of CoII (I), NiII (II), CuII (III), ZnII (IV) and MnII (V) were synthesized using neutral ligand nicotinamide and anionic ligand acesulfame. The structural characterizations of complexes were performed by using elemental analysis, magnetic susceptibility, solid-state UV–Vis, FTIR spectra, thermoanalytic TG-DTG/DTA, and single crystal X-ray diffraction methods. The complexes of I, III, IV, and V were obtained suitable crystal form for single crystal analysis by SC-XRD diffraction. The complexes of II was believed that the others structures so, the spectroscopic results of all the complexes are suitable for each other. The complexes are salt type compounds, and they have 2 mol nicotinamide ligands as monodentate coordination to metal center by pyridine N atoms and 4 mol aqua ligands in coordination sphere and 2 mol anionic acesulfamate ligands located outside of coordination unit as a counter ion. The metal(II) cationic atoms in complexes have octahedral geometry. Thermal decomposition steps of compounds are started with dehydration. © 2018 2-s2.0-85054713426

A novel sensor for fluoride was successfully developed. The sensor was characterized by FT-IR and NMR. The anion sensitivity and selectivity of the compound were studied with some anions (Fˉ, Clˉ, Brˉ, Iˉ, CNˉ, ClO4ˉ, H2PO4ˉ, HSO4ˉ, NO3ˉ and AcOˉ) in DMSO, and their interaction mechanisms were evaluated by 1H NMR titration technique. Thermal properties of the sensor were also investigated. To gain more insight into the three-dimensional geometries and the frontier molecular orbital characteristics of the sensor NA along with its possible deprotonated species, DFT and TD-DFT calculations at B3LYP/6-311 + G(2d,p) level in DMSO were performed. Theoretical results indicate that interaction of the sensor with fluoride anion cause a decrease in the HOMO-LUMO energy gap of NA, which explains the bathochromic shift in the absorption spectrum of the sensor through the addition of fluoride ion.

Three boric acid mediated metal organic frameworks were synthesized by solution method with using succinic acid, fumaric acid and acetylene dicarboxylic acid as a ligand source and sodium as a metal source. The complexes were characterized by FT-IR, powder XRD, elemental analyses and single crystal measurements. The complexes with the formula, C4H18B2Na2O14, C4H16B2Na2O14 and C4H14B2Na2O14 were successfully obtained. BET surface area of complexes were calculated and found as 13.474 m2/g for catena-(tetrakis(?2-hydroxo)-(?2-trihydrogen borate)-(?2-succinato)-di-sodium boric acid solvate), 1.692 m2/g for catena-(tetrakis(?2-hydroxo)-(?2-trihydrogen borate)-(?2-fumarato)-di-sodium boric acid solvate) and 5.600 m2/g for catena-(tetrakis(?2-hydroxo)-(?2-trihydrogen borate)-(?2-acetylenedicarboxylato)-di-sodium boric acid solvate). Hydrogen storage capacities of the complexes were also studied at 77 K 1 bar pressure and found as 0.108%, 0.033%, 0.021% by mass. When different ligands were used, the pore volume, pore width and surface area of the obtained complexes were changed. As a consequence, hydrogen storage capacities also changed. © 2017 Elsevier B.V.

To investigate the effects of ketamine+midazolam and propofol+sevoflurane anesthesia on surgical site hemorrhage during circumcision procedures.The boys undergoing circumcision surgery were included in the study. The patients were divided into two groups. In Group 1 (n = 50), 0.01 mg/kg midazolam and 2 mg/kg IV ketamine were administered. In Group 2 (n = 50), 1 ?g/kg fentanyl, 1 mg/kg lidocaine 2%, and 2-3 mg/kg IV propofol were administered, and patency of airway was ensured with a laryngeal mask airway. The intraoperative bleeding scale was recorded during the procedure to evaluate surgical site bleeding. Hemorrhage was checked for the first three hours using the postoperative bleeding scale to follow the amount of hemorrhage.Intraoperative bleeding scores were significantly higher in Group 1 as compared to Group 2. However, there was no significant difference between the groups regarding frequency of postoperative hemorrhage. Themean blood pressure values measured at 5th, 10th, 15th minutes and recovery room were significantly higher in Group 1.The intraoperative bleeding scores were significantly higher with ketamine+midazolam compared to propofol+sevoflurane. On the other hand this hemorrhage can be controlled easily with appropriate hemostasis, and the amount of blood loss was not clinically significant. We think that our study makes a positive contribution to the literature about the effects of anesthetics on the surgical site bleeding during circumcision.ACTRN12616000189426.

Horner’s syndrome is rarely observed in epidural anaesthesia; it is characterized by ptosis and enophthalmos on the affected side; miosis, anisocoria, and conjunctival hyperemia in the affected eye and anhydrosis, flushing on the affected side of the face. It is usually a complication spontaneously resolved without permanent neurological deficits. Intraoral anaesthesia, stellate, cervical and brachial plexus block, thoracic, lumbar and caudal epidural anaesthesia and intrapleural analgesia are the main causes associated with Horner’s syndrome in anaesthesia. Among the other causes of Horner’s syndrome are head and neck surgery, trauma and puncture of the internal jugular vein. We aimed to present a case with unilateral Horner’s syndrome, which appeared in the morbidly obese parturient after lumbar epidural anaesthesia.