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In this study, the production of two-stage metal-free catalysts from pistachio shells, which are abundant in Turkey and the world, is designed. The first stage of the study includes activated carbon(AC) production, and the second stage includes the production of heteroatom-doped catalysts as a result of hydrothermal heating of the obtained activated carbon with nitric acid. These metal-free catalysts obtained were used for the production of hydrogen (H2) from sodium borohydride (NaBH4) in methanol. In H2 production experiments, the NaBH4 concentration effect, temperature effect and catalyst amount effect and catalyst reusability parameters were investigated. HGR values obtained from the methanolysis using metal-free catalysts treated by the nitric acid/water ratio: 1:2, 1:3, 1:4, 1:5 are 8041, 8955, 10600 and 8333 ml min−1 g−1, respectively. The activation energy (Ea) of the production of H2 from NaBH4(NaBH4–H2–P) in methanol by the metal-free catalyst was 18.19 kJ mol−1. Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), CHNS elemental analysis, scanning electron microscopy (SEM), and nitrogen adsorption analyses were performed for the characterization of the metal-free catalysts obtained. In addition, the mechanism of the obtained metal-free catalysts on the NaBH4–H2–P in methanol is discussed. [ABSTRACT FROM AUTHOR]

Vanadium (IV) chalcogenide materials are of increasing interest for use in catalysis and energy conversion-related applications. Since no ternary compounds are yet known in the V–Se–Te system, we studied ternary VwSeyTe2−y (w = 1.10, 1.13; y = 0.42, 0.72) phases crystallizing in space group P 3 ¯ m1 (no. 164). Two single-crystal specimens with differing compositions of a solid solution were obtained using the ceramic method. All products were characterized by either single-crystal or powder X-ray diffraction. The lattice parameters increase with rising tellurium content in accordance with the larger ionic radius of the tellurium anion compared to selenium. The chemical compositions were confirmed by energy-dispersive X-ray spectroscopy. Furthermore, magnetic measurements mostly revealed antiferromagnetic properties. Simultaneous differential scanning calorimetry/thermogravimetric analyses in a nitrogen atmosphere showed endothermic decomposition accompanied by the formation of VN. The decomposition of VSe and VTe was observed in an argon atmosphere. The results of this work can serve as a basis for the synthesis of new phases in the V–Se–Te and related vanadium chalcogenide systems. [ABSTRACT FROM AUTHOR]

A bimetallic catalyst (Ni/Cu‐MCM‐41) is prepared via co‐condensation method. The latter is characterized by Fourier transform infrared (FT‐IR), X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), diffuse reflectance spectroscopy (DRS), and nitrogen adsorption–desorption analysis. Catalytic performance of Ni/Cu‐MCM‐41 is probed in N‐alkylation of amines with alcohols through a hydrogen autotransfer process. Noteworthy, this catalytic system appears very efficient for synthesis of a range of secondary and tertiary amines in good to excellent isolated yields. Moreover, the catalyst is successfully recovered and reused four times without notable decrease in its activity. [ABSTRACT FROM AUTHOR]

An efficient utilization of broad‐spectrum solar light to harvest energy for photocatalysis in a sustainable manner remains a critical challenge in the area of environmental remediation for a long time. To address this challenge, N‐doped TiO2‐CoS nanocomposite was successfully synthesized for the first‐time via a benign hydrothermal treatment adopting combination of doping, dimensional diversity and coupling strategies. The phase composition, surface morphology, nitrogen adsorption‐desorption analysis and photocatalytic degradation of Rhodamine B dye (RhB) in aqueous solution under simulated sunlight were well characterized and analyzed. The powder X‐ray diffraction patterns demonstrated the crystalline anatase phase of TiO2 in all photocatalysts. Scanning electron microscopy confirmed the formation of N‐doped TiO2 nanofibrous (NTNF) structure without phase alteration of TiO2 and demonstrated the co‐existence of spherical CoS particles that were randomly wrapped within the NTNF fibrous structure making the NTNF‐CoS nanocomposite. Nitrogen adsorption‐desorption analysis revealed higher specific surface area and larger pore volume of NTNF with mesoporous structure compared to those of N‐doped TiO2 nanoparticle (NTNP). The NTNF‐CoS nanocomposite showed superior photocatalytic degradation of RhB under visible light, which was predominantly ascribed to the synergistic effects of enhanced surface area, narrower band gap and efficient separation of photogenerated charge carriers. Thus, the NTNF‐CoS nanocomposite could be considered as a potential candidate for the removal or degradation of micro‐pollutant from the wastewater. [ABSTRACT FROM AUTHOR]

Coordination polymers of 2′,3′,5′,6′-tetramethyl-[1,1′:4′,1′′-terphenyl]-4,4′′-dicarboxylic acid with Cu(II), Co(II) and Cd(II) have been synthesized and characterized by IR spectroscopy, single crystal X-ray diffraction, thermogravimetric analysis and nitrogen sorption studies. Three new 3D-metal–organic frameworks based on 2′,3′,5′,6′-tetramethyl-[1,1′:4′,1′′-terphenyl]-4,4′′-dicarboxylic acid (H 2 L) and Co, Cu, and Cd nodes have been synthesized. The complexes were characterized by elemental, thermogravimetric analysis, IR spectroscopy, single crystal, powder X-ray diffraction and gas sorption experiments. The crystal structure of [Cu 2 L 2 (H 2 O) 2 ] n (1) corresponds to a two-dimensional coordination polymer, in which the metal nodes are two crystallographically equivalent Cu(II) atoms linked by four μ 2 -O,O′ carboxylate ligands in a centrosymmetric {Cu 2 O 10 } paddle-wheel building block. The structure of compound [CoL(dmso)] n (2) has a 3D metal–organic coordination lattice, in which the metal centers are connected by the linear organic ligand to generate a dense three-dimensional coordination polymer. Also, a three-dimensional coordination network was identified in the case of compound [Cd 2 L 2 (dmf)] n (3), whose structure is very similar to that of compound 2. In compound 3 , the carboxylate groups of the linear L2− spacers behave as μ 2 - κ3O, O′:O tridentate bridging ligands. The compounds have a high thermal stability. Polymers 3 and 1 have moderate porosity (specific surface areas of approximately 900 m2/g and 600 m2/g, respectively), while polymer 2 has a dense structure. [ABSTRACT FROM AUTHOR]

Synthetic saponites were successfully used to prepare phase change materials (PCMs) based on paraffin/synthetic saponite. Paraffin/synthetic saponites PCMs were prepared by a solution intercalation process. The PCMs were characterized by powder X-ray diffraction, FT-IR spectroscopy, thermal analyses and nitrogen adsorption. The thermal properties and the stability of PCMs were measured by DSC analysis and from heating–cooling curves. The results showed that the prepared PCMs have a higher heating rate and a lower cooling speed than paraffin because the heat storage was improved with the synthetic saponite. A one-pot synthesis method for obtaining PCM has been successfully developed in this work. The material thus obtained had better results for heat storage applications. [ABSTRACT FROM AUTHOR]

• Hierarchical NiCo 2 O 4 microtubules are synthesized by a template-assisted route. • The as-obtained NiCo 2 O 4 hollow microtubules show high specific surface area (127.1 m2/g). • The as-obtained NiCo 2 O 4 hollow microtubules display rapid response and recovery time to xylene. • The excellent sensing performance is attributed to the unique structural merits. Complex hollow structures with ultra-thin 2D building blocks represent a unique type of functional nanostructures because of their structural merits. In this work, hierarchical NiCo 2 O 4 hollow microtubules assembled by ultra-thin 2D nanosheets have been successfully prepared via a template-assisted process with subsequent etching treatment. The purity, morphology, crystallographic information and surface chemical composition of as-obtained hierarchical NiCo 2 O 4 hollow microtubules are characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM), element mapping, X-ray photoelectron spectroscopy (XPS) and Nitrogen adsorption–desorption analysis. Gas sensing performance of hierarchical NiCo 2 O 4 hollow microtubules is discussed in detail. The results show that hierarchical NiCo 2 O 4 hollow microtubules not only exhibit rapid response/recovery (20/9 s) speed to 100 ppm xylene at relatively low working temperature of 220 °C, but also show low detection limit (1 ppm), high response, excellent gas selectivity and superior long-term stability, which are significantly better than irregular NiCo 2 O 4 nanosheets. The results demonstrate that unique hierarchical NiCo 2 O 4 hollow microtubules are promising candidates for efficient and reliable detection of xylene. [ABSTRACT FROM AUTHOR]

• Selective catalytic reduction of NO x by CO. • Mo helping the dispersion of the Co, Ni or Pt active sites. • Pto and Mo6+ redox pair and low interaction PtMo with the support. • High CO and NO x adsorption to form CO 2 and N 2. • Inhibition of sulfatation and coking over PtMo/Al 2 O 3 -La 2 O 3. Promotional effect of molybdenum on bimetallic Al 2 O 3 -La 2 O 3 -based catalysts was investigated in the selective catalytic reduction (CO-SCR) reaction. The physicochemical properties of the solids were evaluated through X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), nitrogen physisorption analyses, Temperature programmed reduction (TPR), NH 3 -temperature programmed desorption (NH 3 -TPD) and Transmission electron microscopy (TEM). Structural characterizations confirmed the formation of porous nanostructured solids with molybdenum helping the dispersion of the Ni or Pt active sites close to the molybdenum particles. The catalysts have acid sites of medium to low strengths effectively enhancing the catalytic activity of the solids. Investigation of the various active sites revealed PtMo supported on Al 2 O 3 -La 2 O 3 as the best catalyst using distinct temperatures and poisoning conditions in the CO-SCR reaction, rather than NiMo and CoMo counterparts. The oxidation of the species and phase transformation were more significant on the CoMo than NiMo catalyst, with the latter having a modest performance. The low interaction of the PtMo with the support provided the formation of a Pto and Mo6+ redox pair, which resulted in high CO and NO x adsorption to form CO 2 and N 2. This was due to the synergistic effect of valence-rich Mo transition oxides with Pt species, resulting in the inhibition of irreversible sulfatation and coking over PtMo/Al 2 O 3 -La 2 O 3 catalyst. [ABSTRACT FROM AUTHOR]

Supercritical solvent impregnation (SSI) is a green unconventional technique for preparing amorphous drug formulations. A mesoporous nanostructured ZnO (mesoNsZnO) carrier with 8-nm pores, spherical-nanoparticle morphology, and an SSA of 75 m2/g has been synthesized and, for the first time, subjected to SSI with poorly water-soluble drugs. Ibuprofen (IBU), clotrimazole (CTZ), and hydrocortisone (HC) were selected as highly, moderately, and poorly CO2-soluble drugs. Powder X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, nitrogen adsorption analysis, and ethanol extraction coupled with ultraviolet spectroscopy were employed to characterize the samples and quantify drug loading. Successful results were obtained with IBU and CTZ while HC loading was negligible, which could be related to different solubilities in CO2, drug size, and polarity. Successful SSI resulted in amorphous multilayer confinement of the drug. The mesoNsZnO-IBU system showed double drug loading than the mesoNsZnO-CTZ one, with a maximum uptake of 0.24 g/g. Variation of contact time during SSI of the mesoNsZnO-IBU system showed that drug loading triplicated between 3 and 8 h with an additional 30% increment between 8 h and 24 h. SSI did not affect the mesoNsZnO structure, and the presence of the adsorbed drug reduced the chemisorption of CO2 on the carrier surface. [ABSTRACT FROM AUTHOR]