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Aluminum oxide is an important ceramic material for coatings and catalyst support for high-temperature applications. In this work, spherical aluminum oxide (AlOx) nanoparticles (NPs) are synthesized via the thermal decomposition of aluminum oleate using oleic acid as a stabilizing agent. X-ray diffraction analysis confirms its crystallization to γ-Al2O3 and α-Al2O3 after annealing at 700 and 1100 °C, respectively, revealing their gradual phase transition. Morphological and crystallinity changes of spherical nanoparticles upon annealing were investigated by transmission electron microscopy. The chemical composition and phase transitions to Al2O3 NPs were supported by X-ray photoelectron spectroscopy as a function of temperature. Monolayer assembly of as-synthesized NPs onto quartz substrate was performed using organic linker molecules (11-phosphonoundecanoic acid), which was confirmed by atomic force microscopy imaging. The optical band gap of the monolayer assembly was evaluated after annealing at different temperatures along with transmittance properties to compare with the current literature by UV–visible spectroscopy. [ABSTRACT FROM AUTHOR]

This manuscript presents the preparation of polymer layers based on polythiophene (PTh) and its 3-substituted derivatives (substituents 4-(CH3O)C6H4 and 4-(CF3)C6H4 marked as PThOCH3 and PThCF3, respectively) on platinum electrodes by cyclic voltammetry (CV). The polymerization process and the morphology of resulting layers were discussed analysing of CV-voltammograms and scanning electron microscopy (SEM), respectively. Subsequently, the prepared polymers were tested as active/sensitive media of two types of sensors: (i) electrochemical sensor detecting ammonia in aqueous environment, whose response was evaluated by electrochemical impedance spectroscopy (EIS); (ii) chemiresistor detecting NH3 in atmosphere, whose response was evaluated by measurement of resistance. It was found that both the physical (morphology, homogeneity, relative thickness) and receptor properties of the polymer layer deposited on electrode surface are significantly affected by the nature of substituent attached to the thiophene ring. The mutual context of ammonia detection in both environments is discussed. [ABSTRACT FROM AUTHOR]

The characterization of materials surface is essential, as the initial in vivo response is highly dependent on surface properties. Surface topography is a key aspect that influences the response of cells to products resulting from interaction with the surface of a titanium alloy, including parameters such as adhesion, spread, migration, proliferation, and differentiation of cells. Various surface modifications are used to improve the interface properties between MC3T3 and NHDF cells and the Ti–13Nb–13Zr-based surface. Among the techniques discussed in this paper, scanning electron microscopy, laser confocal scanning microscopy, and computed tomography are adequate to investigate materials topography at different scale levels. Chemical characterization of the outer layers of Ti–13Nb–13Zr samples was performed with X-ray photoelectron spectrometry. Studies have shown that the surfaces resulting from the treatment enabling the formation of titanium oxide and zirconium oxide show the lowest cytotoxicity. Implants made from the new generation of titanium alloy, not containing toxic elements, with the use of surface modification could be an essential innovation in implantology. [ABSTRACT FROM AUTHOR]

Rapid developments in the electric industry have promoted an increasing demand for lithium resources. Lithium in salt lake brines has emerged as the main source for industrial lithium extraction, owing to its low cost and extensive reserves. The effective separation of Mg2+ and Li+ is critical to achieving high recovery efficiency and purity of the final lithium product. This paper summarizes Mg2+/Li+ separation materials and methods in the field of lithium recovery from salt lake brines. The review begins with an introduction to the global distribution and demand for lithium resources, followed by a description of the materials used in various separation techniques, including precipitation, adsorption, solvent extraction, nanofiltration membrane, electrodialysis, and electrochemical methods. A comparison, analysis, and outlook of such methods are comprehensively discussed in terms of principles, mechanisms, synthesis/operation, development, and industrial applications. We conclude with a presentation of challenges and insights into the future directions of lithium extraction from salt lake brines. A combination of the advantages of various materials is the most logical step toward developing novel methods for extracting lithium from brines with high separation selectivity, stability, low cost, and environmentally friendly characteristics. [ABSTRACT FROM AUTHOR]

The application of TiO2 acetone monitor is highly limited by the high operating temperature and poor sensitivity. In this work, black TiO2 (B-TiO2) is produced by Ti3+ self-doping and is followed by Ag modification to form B-TiO2@Ag. It is first demonstrated that the operating temperature and sensitivity of TiO2 to acetone can be promoted evidently. By introducing a Ti3+ self-doped layer on the surface of TiO2, as observed in TEM images, the band gap of TiO2 is reduced to 3.01 eV. Ag surface decoration is carried out for the enhancement of electron generation. Optical absorption and the Hall effect results prove that B-TiO2@Ag exhibits highest photoelectrical properties. As a result, the B-TiO2@Ag gas sensor with a low operating temperature at 250 °C and high response of 68.19 to 50 ppm acetone is realized. The low detection limit of B-TiO2@Ag sensor reaches 887 ppb, which provides an applicable way for non-invasive detection of blood glucose. [ABSTRACT FROM AUTHOR]

Hierarchical magnesium oxide (MgO) microspheres with high adsorption capacity of heavy metal ions and potent antibacterial activity were synthesized by an aerosol-assisted method. It is a facile, efficient and economical route for the large-scale synthesis of MgO microspheres using neither precipitants nor surfactants. The prepared MgO microspheres are made up of nanosheets with large pore volume, and they exhibit the maximum adsorption capacity of Pb(II) which is 4091 mg/g. The adsorption processes of Pb(II) are well accorded with pseudo-secondary kinetic model and Langmuir thermodynamic model. The adsorption mechanism was studied by analyzing the adsorbed products which indicate the hydroxylation of the MgO surface is crucial for chemisorption. Additionally, MgO microspheres show excellent antibacterial activity against both Escherichia coli and Staphylococcus aureus. The as-prepared MgO microspheres show promising application for the treatment of heavy metal ion and bacteria-contaminated wastewater. [ABSTRACT FROM AUTHOR]

Anatase TiO nanoparticles were synthesized from sol-gel processing, and they were used as a precursor for titanate nanotubes (TNT) formation. TNT were synthesized under reflux heating of anatase TiO in concentrated NaOH solution followed by repeated washing with distilled water and 0.1 M HCl. The nanotubular structure was preserved till 450 °C, above which nanorod formation started. The as-synthesized nanotubes were found to have mixed crystal structure of anatase and NaHTiO·nHO (where 0 < x < 2), contrary to what has been reported before. The XRD peaks of titanate were slightly shifted to higher angles upon calcination along with prominent anatase peaks. Complete transformation to nanorods occurred at 600 °C and crystal structure was transformed to NaTiO and anatase. Sodium presence in TNT was confirmed by EDX, and Na-O and H-O-H along with Ti-OH vibrations were found by FTIR. Ti-OH/H-O-H vibrations were less prominent for samples calcined at 500 °C and above, which confirms structural water loss is associated with morphological change. The as-synthesized TNTs had a specific surface area of 157 m g, and it decreased by increasing calcination temperature. TNTs were applied to methylene blue aqueous solution to observe their decolorization capability under UV irradiation. The as-synthesized TNTs showed enhanced photocatalytic decolorization as compared to anatase titania nanoparticles due to presence of Ti-OH groups and higher specific surface area. The photocatalytic activity reduced when TNTs were annealed at high temperatures. The changes in the photocatalytic activity are related to the existence of hydroxyl groups in the structure, decrease in specific surface area of annealed nanotubes, change in morphology from nanotubes to nanorods, and bandgap shift to visible light when TNTs were calcined at higher temperatures. [ABSTRACT FROM AUTHOR]