Methanol dehydration process to dimethyl ether (DME) has been considered as one of the main routes to produce clean fuel i.e. DME. Thus, efficient catalyst is highly required for selective production of DME. Herein, UiO-66 was used as a precursor for the synthesis of zirconium oxide sulfate embedded carbon (ZrOSO4@C). The synthesis method involves one-step carbonization of UiO-66 in the presence of sulfuric acid (10 wt.%). Materials characterization using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), Raman spectroscopy approve the formation of high crystalline phase of ZrOSO4@C. Nitrogen adsorption-desorption isotherms and high resolution transmission electron microscope (HR-TEM) confirm the mesopore structure of the materials. Acidity analysis using pyridine-temperature programmed desorption (TPD), isopropanol dehydration corroborate that ZrOSO4@C has weak and intermediate acidic sites making ZrOSO4@C effective catalyst for methanol dehydration to DME. The materials offered full conversion (100%) with excellent selectivity (100%) at a relatively low temperature (250 oC). The catalyst exhibited a long-term stability for 120 h. Based on these results, DME is produced efficiently in terms of conversion, selectivity, and long-term stability.

Tin dioxide (SnO2) and titanium dioxide (TiO2) are popular metal oxide semiconductors; they are explored for many applications because of their unique properties. This paper details that electronic and electrical properties of SnO2 and TiO2 can be synergistically combined in an one-dimensional nanostructure, such as electrospun nanofibers. The resulting composite nanofibers (CNFs) showed beneficial properties when used as a photoanode in dye-sensitized solar cells (DSSCs). In particular, the CNFs showed higher conduction band energy than SnO2 and higher electrical conductivity than TiO2. The SnO2-TiO2 CNFs are synthesized by electrospinning a polymeric solution containing equimolar concentration of tin chloride and titanium alkoxide precursors and subsequent annealing. The composite formation is demonstrated by X-ray diffraction and energy dispersive X-ray measurements and morphology by …

Hierarchical porous zeolitic imidazolate frameworks (HZIFs) are promising materials for several applications, including adsorption, separation, and nanomedicine. Herein, the conversion of zinc hydroxide nitrate nanosheets into HZIF-8 nanocomposite with graphene oxide (GO) and magnetic nanoparticles (MNPs) is reported. The conversion takes place at room temperature in water. This approach has been successfully applied for the formation of leaf-like ZIF(ZIF-L), and their nanocomposites with nanoparticles, such as GO and MNPs. This method offers a simple approach for the synthesis of tunable pore structure using nanoparticles and fast room temperature conversion (30 min) without any visible residual impurities of zinc hydroxide nitrates. The applications of HZIF-8, ZIF-L, and their nanocomposites, for CO2 sorption, exhibit excellent adsorption properties. The synthesized composites exhibit enhanced CO2 adsorption capacity due to the synergistic effect between nanoparticles (GO, or MNPs), and ZIF-8. The materials have good potential for further applications.

The development of simple, low-cost, and specific detection method for mercury (Hg(II)) ions in aqueous media using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) is a challenge due to matrix interferences and acidity that destroy weak interactions. Herein, a new binary matrix consists of mefenamic acid, and thymine (T) is applied for simple and specific detection of Hg(II) in aqueous solution and blood sample. Mass spectra show metal-to-ligand ratio of 1:2 (Hg(II):T) in which Hg(II) ions are bound to two T molecules and two water molecules, i.e., [Hg(T)2(H2O)2]. The method is simple and fast, and requires cheap reagents. In addition, the spectra show extremely specific signals for Hg(II) ions and insignificant signals in case of other competing metal ions. The concept of our protocol can be applied for other metals. The new matrix may be used for the analysis of small molecules with minimal interferences peaks.

This article deals with investigation of fine-scale precipitation in Al-Mg-Zn alloys with compositions of Al - 2 at% Mgx
at% Zn, (x = 1.8, 2 and 4.2). The precipitates morphology was examined by scanning electron microscope (SEM) and
correlated with the microhardness (HV) and differential scanning calorimetry (DSC) of the specimens. The precipitates
are characterized as ’ (MgZn2) and  (MgZn2) phases of hexagonal structure of the same composition with a slight
difference in lattice parameters. In addition, T-phase pf composition (Mg32 (Al, Zn)49) having a cubic crystal structure.
Owing to the determined activation energies of the precipitates, the kinetics associated with their nucleation and growth
can be characterized. The thermal energy acquired during aging leads to the agglomeration of precipitates to or larger
particle sizes.

This article deals with investigation of fine-scale precipitation in Al-Mg-Zn alloys with compositions of Al - 2 at% Mgx
at% Zn, (x = 1.8, 2 and 4.2). The precipitates morphology was examined by scanning electron microscope (SEM) and
correlated with the microhardness (HV) and differential scanning calorimetry (DSC) of the specimens. The precipitates
are characterized as ’ (MgZn2) and  (MgZn2) phases of hexagonal structure of the same composition with a slight
difference in lattice parameters. In addition, T-phase pf composition (Mg32 (Al, Zn)49) having a cubic crystal structure.
Owing to the determined activation energies of the precipitates, the kinetics associated with their nucleation and growth
can be characterized. The thermal energy acquired during aging leads to the agglomeration of precipitates to or larger
particle sizes.

This article deals with investigation of fine-scale precipitation in Al-Mg-Zn alloys with compositions of Al - 2 at% Mgx
at% Zn, (x = 1.8, 2 and 4.2). The precipitates morphology was examined by scanning electron microscope (SEM) and
correlated with the microhardness (HV) and differential scanning calorimetry (DSC) of the specimens. The precipitates
are characterized as ’ (MgZn2) and  (MgZn2) phases of hexagonal structure of the same composition with a slight
difference in lattice parameters. In addition, T-phase pf composition (Mg32 (Al, Zn)49) having a cubic crystal structure.
Owing to the determined activation energies of the precipitates, the kinetics associated with their nucleation and growth
can be characterized. The thermal energy acquired during aging leads to the agglomeration of precipitates to or larger
particle sizes.

Network of new quaternary borate glasses Bi2O3–Y2O3–Al2O3–B2O3 was studied by FTIR and UV spectroscopies.
According to the FTIR results, the addition of Y2O3 increases the amount of bridging oxygens and changes the coordination
number of the glasses by creating [BO4] structural units. FTIR investigations explained the increase of
the computed elastic moduli according to Makishima–Mackenzie model. The optical parameters such as the UV
transmission, the polarizability, and the basicity are found to be sensitive to the concentration of Y2O3. The results
of the elastic moduli and the optical parameters were interpreted in terms of the vibrations of structural groups
and the strength of the bonds.

Network of new quaternary borate glasses Bi2O3–Y2O3–Al2O3–B2O3 was studied by FTIR and UV spectroscopies.
According to the FTIR results, the addition of Y2O3 increases the amount of bridging oxygens and changes the coordination
number of the glasses by creating [BO4] structural units. FTIR investigations explained the increase of
the computed elastic moduli according to Makishima–Mackenzie model. The optical parameters such as the UV
transmission, the polarizability, and the basicity are found to be sensitive to the concentration of Y2O3. The results
of the elastic moduli and the optical parameters were interpreted in terms of the vibrations of structural groups
and the strength of the bonds.

This study reports on the optical parameters of MoO3–V2O5–PbO films. The measured transmittance spectra in
the spectral range 300–2500 nm was used for precise calculations of the complex index of refraction (real (n) and
imaginary (k) parts) as well as the film thicknesses. With the addition of MoO3, a blue shift of the absorption
edge was represented while the index of refraction (n) was decreased. The decrease of the index of refraction was
discussed in terms of the dispersion model. A good correlation between the bulk modulus Kop, the optical band
gap Eg and the index of refraction was observed. With the help of Kop, Eg and n values, the electronic polarizability
has been calculated for the films under study. The results well discussed in terms of the density, electronegativity
and polarizability changes due to the addition of MoO3 content.