Mesoporous titania aerogel with high surfaces area (1086
m
2
g
−1) were prepared by two steps: heterogeneous precipitation of aqueous solution containing TiOSO
4 and ammonia, followed by continuous ...supercritical extraction with CO
2 after replacement of the water with
n-propanol/benzene mixture. The total pore volume of as obtained aerogel is 3.44
cm
−3
g
−1 and the main pore diameter is 20–80
nm. The structure evolution of titania aerogel during heating was studied by DTA and high temperature XRD analyses. At 450
°C titania aerogel transforms to polycrystalline anatase. The morphology and microstructure characteristics of both titania aerogel and anatase samples were obtained by SEM, HRTEM, BET and BJH methods. Anatase reveals high photocatalytic activity during the degradation of 4-chlorophenol in aqueous suspension.
Sonochemical synthesis followed by supercritical drying was used to prepare MgO nanoparticles from Mg(OCH3)2 and Mg(OC2H5)2. Their physicochemical properties were examined by means of X-ray ...diffraction (XRD), simultaneous thermal analysis (DTA, TG, EGA), specific surface area measurement, scanning and transmission electron microscopy. The dehydrated MgO oxides were free of –OCH3 groups. The highest values of specific surface area (1236 m2 g−1) have been obtained by hydrolysis of magnesium methoxide using toluene as solvent agent.
Hydrous iron (III) oxides agglomerated into uniform porous spherical clusters with submicrometre size and high specific surface area were obtained. Homogeneous precipitation of iron (III) sulphate ...was carried out in boiling aqueous solution that contained excess of urea. The prepared precursor precipitates were heated for 2 h at various temperature (from 200 to 800 °C) to yield fine iron oxides powders. The structure evolution during heating of powders was investigated by X-ray diffraction (XRD). The morphology and microstructure characteristics were also obtained by means of scanning electron microscopy (SEM), (BET) and (BJH). In order to see the phase transition temperature thermogravimetric analysis/differential thermal analysis studies were performed. It was found that formation of different hydrous iron (III) oxides was affected by experimental conditions: aging time, mixing procedure, pH and temperature.
The study reported herein describes for the first time a method for producing defect-free graphene directly from its mineral ore. This was achieved by treating graphite ore in an ionic liquid ...containing biphasic solvent system, applying pressurized intense cavitation ultrasound. Without any graphite ore pre-treatment, large few layer thick graphene sheets, as well as micrometric layered crumpled graphene structures, were produced. This opens new opportunities for the development of graphene-based technologies.
Here we report a novel method of intercalation of a quaternary ammonium salt bearing a polymerizable group in between graphite galleries. By the exfoliation of the intercalate during its subsequent ...polymerization with n -butyl methacrylate, a polymer membrane with homogenously dispersed graphene nanostructures was obtained.
This work describes a straightforward procedure for the preparation of graphene by opening multi-walled carbon nanotubes (CNT), using ionic liquids (IL) as lubricating and stabilizing agents. The ...sequential application of vacuum and sonication allows the successful opening and unrolling of the CNT, and the final nanocarbon morphology is IL-dependent. This enabled the preparation of epoxy-based nanocomposites with morphologically distinct carbon nanofillers. The CNT–IL mixtures and nanocomposites obtained were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy.
Rutile TiO
2
and Eskolaite Cr
2
O
3
powders were mechanically mixed and fed into the plasma jet simultaneously. The influence of the ratio of components on behavior of the plasma-sprayed coatings was ...observed using two different compositions, both at two different feeding distances. The produced coatings were analyzed by XRD, SEM, XPS, and light microscopy. Electrical resistivity was measured at voltages from 1 to 100 V. Photocatalytic decomposition of butane on the coatings was studied using visible light together with a setup typically used for UV-light tests. For the coatings with high TiO
2
content, besides rutile, low anatase content was identified. The coatings with predominant Cr
2
O
3
exhibited lower porosity and higher hardness. All coatings are relatively efficient photocatalysts for butane decomposition. Moreover, they have good mechanical properties governed predominantly by Cr
2
O
3
content as the harder component. It was proven that the spray process led to obtaining of robust photocatalytically active coatings.
This study examines the photocatalytic activity of coatings produced by atmospheric plasma spraying (APS). The applied spraying tools were gas-stabilized (GSP) and water-stabilized (WSP) plasma guns. ...The TiO2–Fe2O3 powder with and without Na2SiO3 additive was produced as agglomerates suitable for feeding into the plasma jet. The coatings are analyzed by scanning electron microscopy, X-ray fluorescence and X-ray diffraction. Photocatalytic degradation of butane under UV and under visible light, as well as the growth kinetics of the products – carbon dioxide and carbon monoxide – is quantified for all coatings and compared with a pure TiO2 coating. The coatings show a lamellar structure, as it is typical for this process. However, their porosity is rather high. Anatase titania from the feedstock powder is converted into rutile phase in all coatings; whereas the presence of FeTiO3 is detected in the coating without Na2SiO3 made by WSP and metallic iron in the GSP coating. The coating from powder with Na2SiO3 admixture is partly amorphous. This coating is photocatalytically active especially under UV, whereas under visible light it is overcome by the WSP coating. The GSP coating has the best photocatalytic activity under both different radiations.
Macrocrystalline oxides of alkaline earth metals (Mg and Ca) or light metals (Al and Ti) can respond to standard warfare agents such as sulfur mustard, soman, or agent VX. In this paper, we compared ...the decontamination ability of sodium hydroxide (NaOH) and sodium hypochlorite (NaClO) for nitrogen mustards (cyclophosphamide CP and ifosfamide IFOS) with a new procedure using a destructive sorbent based on nanocrystalline and nanodispersive titanium dioxide (TiO
) as a new efficient and cheap material for complete decontamination of surfaces.
Titanium (IV) dioxide nanoparticles were prepared by the homogeneous hydrolysis of titanium(IV) oxysulfate (TiOSO
) with urea. The as-prepared TiO
nanoparticles were used for the fast and safe decontamination of cytostatics from the nitrogen mustard family (CP and IFOS) in water. The adsorption-degradation process of cytostatics in the presence of TiO
was compared with decontamination agents (0.01 M solution of sodium hydroxide and 5% solution of sodium hypochlorite). The mechanism of the decontamination process and the degradation efficiency were determined by high-performance liquid chromatography with mass spectrometry.
It was demonstrated that a 0.01 M solution of sodium hydroxide (NaOH) decomposes CP to 3-((amino(bis(2-chloroethyl)amino)phosphoryl)oxy)propanoic acid and sodium hypochlorite formed two reaction products, namely, IFOS and 4-hydroxy-cyclophosphamide. IFOS is cytotoxic, and 4-hydroxy-cyclophosphamide is a known metabolite of CP after its partial metabolism by CYP/CYP450. IFOS degrades in the pres¬ence of NaOH to toxic IFOS mustard. Titanium(IV) dioxide nanoparticles adsorbed on its surface CP after 5 minutes and on IFOS after 10 minutes. The adsorption-degradation process of CP in water and in the presence of TiO
led to 4-hydroxy-cyclophosphamide and IFOS, respectively, which decayed to oxidation product 4-hydroxy-ifosfamide.
Nanodispersive TiO
is an effective degradation agent for decontamination of surfaces from cytostatics in medical facilities.
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