Synthesis of MIL-101@g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> nanocomposite for enhanced adsorption capacity towards CO<Subscript>2</Subscript>

MIL-101@g-C₃N₄ nanocomposite was prepared by solvothermal synthesis and used for CO₂ adsorption. The parent materials (MIL-101 and g-C₃N₄) and the MIL-101@g-C₃N₄ were characterized by X-ray diffraction, argon adsorption/desorption, Fourier transform infrared spectroscopy, thermal analysis (TG/DTA), transmission electronic microscopy, and Energy-dispersive X-ray spectroscopy. The results confirmed the formation of well-defined MIL-101@g-C₃N₄ with interesting surface area and pore volume. Furthermore, both MIL-101 and MIL-101@g-C₃N₄ were accomplished in carbon dioxide capture at different temperatures (280, 288, 273 and 298 K) at lower pressure. The adsorption isotherms show that the nanocomposite has a good CO₂ adsorption affinity compared to MIL-101. The best adsorption capacity is about 1.6 mmol g^?1 obtained for the nanocomposite material which is two times higher than that of MIL-101, indicating strong interactions between CO₂ and MIL-101@g-C₃N₄. This difference in efficacy is mainly due to the presence of the amine groups dispersed in the nanocomposite. Finally, we have developed a simple route for the preparation of an effective and new adsorbent for the removal of CO₂, which can be used as an excellent candidate for gas storage, catalysis, and adsorption.     

Cardiovascular and neurohumoral responses to behavioral challenge as a function of race and sex.

Cardiovascular and hormonal responses to a structured interview, an electronic video game, a cold pressor test, and exercise on a bicycle ergometer were assessed in 83 normotensive Black and White men and women (aged 25–44 yrs). Black Ss showed significantly greater diastolic blood pressure (DBP) responses than White Ss during the cold pressor test, which were not accounted for by an increase in plasma catecholamines. Exercise produced reliably greater systolic blood pressure (SBP) increases in Black women than in Black men or White women. Men showed significantly greater SBP and DBP changes than women during the video game. The pattern of physiological reactivity elicited by challenge may be related to the Ss' race and sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High Stable Al-MCM-41: Structural Characterization and Evaluation for Removal of Methylene Blue from Aqueous Solution

Aluminosilicate (Al-MCM-41) was synthesized via a modified wet-method in a Si/Al atomic ratio of 13.64:1.00 and calcination at 500 °C. The structural     

Electrochemical Investigation of Calcium Substituted Monoclinic Li3V2(PO4)3 Negative Electrode Materials for Sodium- and Potassium-Ion Batteries

Herein, the electrochemical properties and reaction mechanism of Li_3‒2xCa_xV₂(PO₄)₃/C (x = 0, 0.5, 1, and 1.5) as negative electrode materials for sodium-ion/potassium-ion batteries (SIBs/PIBs) are investigated. All samples undergo a mixed contribution of diffusion-controlled and pseudocapacitive-type processes in SIBs and PIBs via Trasatti Differentiation Method, while the latter increases with Ca content increase. Among them, Li₃V₂(PO₄)₃/C exhibits the highest reversible capacity in SIBs and PIBs, while Ca_1.5V₂(PO₄)₃/C shows the best rate performance with a capacity retention of 46% at 20 C in SIBs and 47% at 10 C in PIBs. This study demonstrates that the specific capacity of this type of material in SIBs and PIBs does not increase with the Ca-content as previously observed in lithium-ion system, but the stability and performance at a high C-rate can be improved by replacing Li⁺ with Ca²⁺. This indicates that the insertion of different monovalent cations (Na⁺/K⁺) can strongly influence the redox reaction and structure evolution of the host materials, due to the larger ion size of Na⁺ and K⁺ and their different kinetic properties with respect to Li⁺. Furthermore, the working mechanism of both LVP/C and Ca_1.5V₂(PO₄)₃/C in SIBs are elucidated via in operando synchrotron diffraction and in operando X-ray absorption spectroscopy.     

Far-infrared spectroscopy of interlayer vibrations of Cu(II), Mg(II), Zn(II), and Al(III) intercalated muscovite

In this study the intercalation behavior of di- and trivalent cations like Cu(II), Mg(II), Zn(II), and Al(III) into the interlayers of muscovite was investigated by X-ray diffraction and far-infrared spectroscopy. The X-ray diffractometry shows that the original material is a muscovite 2M(1). During the metal cation treatment, new peaks occur at about 1.1 and 2.2 nm, while the original peaks strongly decrease. This gives evidence for the formation of a strongly modified mica structure. The occurrence of bands at low wavenumbers (93 cm(-1) and 104 cm(-1)) in the far-infrared spectra show that the untreated material was partly dehydroxylated. The strong decrease of the band at 93 cm(-1) and the occurrence of a band at 110 cm(-1) during the intercalation are strong hints about the rehydroxylation of the mineral. The strong increase of the band intensity at 88 cm(-1) and the occurrence of a band at 119 cm(-1) in the treated muscovites prove the formation of a new, strongly modified mica phase that has both the new cations and the potassium incorporated into the interlayer space.     

Preparation of Nano-TiO2/Diatomite Composites by Non-hydrolytic Sol–Gel Process and its Application in Photocatalytic Degradation of Crystal Violet

Silicon - The dispersion of anatase TiO2 on diatomic material was a prospective route to avoid agglomerates of these particles. In this work, the TiO2/diatomite composites were prepared using a...     

Magnetic Cores with Porous Coatings: Growth of Metal‐Organic Frameworks on Particles Using Liquid Phase Epitaxy

A novel method for the homogeneous coating of magnetic nanoparticles with metal organic frameworks (MOFs) is reported. Using a liquid phase epitaxy process, a well‐defined number of [Cu₃(btc)₂]nH₂O, HKUST‐1, layers are grown on COOH terminated silica magnetic beads. The structure and porosity of the deposited MOF coatings are studied using X‐ray diffraction and BET analysis. In addition, size and shape of the fabricated composites are analyzed by transmission electron microscopy. Potential applications of particle based MOF films include catalytic coatings and chromatographic media.     

BET Sample Pretreatment of Synthetic Ferrihydrite and its Influence on the Determination of Surface Area and Porosity

Ferrihydrite is a poorly-ordered iron oxyhydroxide which possesses a high specific surface area (>200 m²/g). This makes it an important constituent for surface related processes in nature and catalysis. This study focuses on the precautions that have to be taken in the sample preparation prior to BET measurements in order to avoid essential structural transformations. The experiments showed that temperatures between 90 and 120°C are necessary to remove surface contaminations and simultaneously prevent structural transformation of the ferrihydrite during the outgassing procedure. Furthermore, care has to be taken to keep the humidity low in the immediate proximity of the sample, due to the strong impact of this parameter on the structural stability of ferrihydrite.     

Phosphorus removal and recovery from wastewater by tobermorite-seeded crystallisation of calcium phosphate.

Investigations were focused on the development of a technology for phosphorus (P) recovery straight from wastewater. Facing the finiteness of the natural resources of this essential nutrient, the declared goal must be the sustainable use of available phosphorus sinks such as wastewater treatment plants (WWTP) for the generation of P rock substitutes. A feasible method for simultaneous elimination and recovery of phosphorus from wastewater proved to be the P-RoC process - the phosphorus recovery from wastewater by induced crystallisation of calcium phosphate, applying tobermorite-rich waste compounds of the construction industry. The experiments were performed in fixed bed-, stirred- and expanded bed reactors in laboratory--as well as in pilot-scale experiments. The efficiency and longevity of the P-RoC process was determined by the supply of Ca ions and the initial P concentration. Total P (P-tot) contents in the generated crystallisation products of up to 13% P-tot (30% P2O5) were achieved. Mineralogical investigations proved the formation of a hydroxy-apatite-(HAP)-like coating onto the seed material's surface. Reuse options for the generated crystallisation products, such as substitute for phosphate rock or as new fertiliser, were assessed.