Photocatalytic and photoelectrocatalytic degradation of metoprolol tartrate in aqueous media by recyclable Co doping Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/TiO<Subscript>2</Subscript> magnetic core–shell nanocomposites

Magnetically recoverable cobalt doping Fe₃O₄/TiO₂ magnetic nanocomposites with an acceptable core–shell structure were prepared via a sol-gel process at low calcination temperature. The crystalline size and structure, morphology, and magnetic properties of resulting particles have been characterized by X-ray diffraction (XRD), fourier transform infrared (FT-IR), FT-Raman, high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometry (VSM). Metoprolol tartrate (MET) as a pharmaceutical pollutant was used to observe the photocatalytic degradation ability of the magnetically recoverable particles. The process of degradation under UV irradiation at controlled temperature was studied and the remaining concentrations of MET as a contaminant were measured by UV-Vis spectrometer at λ = 229 nm. This ability remained 95.76% after three times of repetitive use at the same conditions. Various parameters such as reaction temperature, pH, and speed of stirring of the aqueous solution had an effect on the rate of degradation. The amount of cobalt dopant and nanocomposites are also effective on the rate of degradation. Coupling of electrical current with photocatalytic process has proven to be effective in the degradation of MET aqueous solution clearly.     

The effects of La2O3 on the early stages of crystallization for MgO-Al2O3-SiO2-TiO2-La2O3 glass-ceramics

The early stages of crystallization for MgO-Al₂O₃-SiO₂-TiO₂-La₂O₃ glasses with different La₂O₃ concentrations were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The glass transition temperature (Tg) of the glass decreases at first and then increases again with increasing La₂O₃ concentration. This indicates that the structure of the glass becomes weaker at first and then stronger again. Lanthanum acts in glasses as network modifier and will usually decrease the network connectivity of the glass structure. Nevertheless, if the La₂O₃ concentration is high enough, the oxygen and other ions start to agglomerate around La, resulting in a more closely packed structure. Heat-treatment of the sample with x = 0.1 at 770–810 °C results in the precipitation of a droplet phase with higher mean atomic weight embedded in a matrix with lower mean atomic weight. The initial crystalline phase magnesium aluminum titanate (MAT) precipitates from the droplet phase. Nevertheless, for the sample with x = 0.4, dendrite-like structure could be observed after heat-treatment of the glass at 810 °C. Furthermore, the crystalline phase first precipitated is the lanthanum containing perrierite, which could be attributed to the rearrangement of the glass structure as an effect of La³⁺ incorporation.     

Microwave synthesis of LaMO3 (M = Mn, Co, Fe) perovskites from crystalline hydrates of nitrates

The possibility of synthesizing perovskite-type LaMO₃ (M = Mn, Co, Fe) oxides by microwave irradiation of crystalline hydrates of nitrates was studied. Oxides with the perovskite structure form at the microwave irradiation stage; however, the resulting product is not singe-phase. Additional thermal treatment of the microwave synthesis product at 600 to 900°C for 5 h is needed for a single-phase oxide to be formed in the case of M = Mn. In the case of M = Co or Fe, the samples contain considerable amounts of the simple oxides La₂O₃ and Fe₂O₃ or Co₃O₄ along with the perovskite. The synthesized products were investigated in nitrous oxide decomposition and methane oxidation as model reactions. As compared to the samples obtained by other techniques, they have a larger specific surface area and are more active.     

Synthesis of La9.33Si6O26 nano-photocatalysts by ultrasonically accelerated method for comparing water treatment efficiency with changing conditions

Lanthanum silicates nanoparticles with La_9.33Si₆O₂₆ formula provided through sonochemical procedure in the presence of tetraethylenepentamine. The amine of tetraethylenepentamine plays two roles of alkaline agent and masking agent for controlling the morphology and size in the reaction process. Effect of sonication time and applying sonication method (non-stop or pulsed) as important parameters studied on the product characteristics. The obtained ideal sample applied as photocatalyst material for degradation of series of organic dyes. Also, dye concentration, catalyst dosage and pH are operational parameters in water treatment that choose to study in the designed photocatalytic tests. The photocatalytic degradation mechanism inquired to study the scavengers for active agents. Therefore, ideal efficiency (61.70%) obtained in the presence of 0.03 g La_9.33 Si₆ O₂₆ nano-photocatalysts in 10 ppm acid red 14 in the pH of 11 which proceeds in terms of mechanism with the help of superoxide species.     

Effect of lattice strain on structure,morphology, electrical conductivity and magneto-optical and catalytic properties of Ni-doped Mn3O4 nano-crystallites synthesized by microwave route

Ni-doped Mn₃O₄ nanoparticles (NPs) were synthesized by a simple one-pot microwave combustion procedure utilizing urea as a fuel. X-ray diffraction, transmission electron microscopy (TEM), diffuse reflectance spectroscopy, Photoluminescence spectra, and vibrating sample magnetometer. The particle size and the crystalline size measured from the HR-TEM monographs and XRD study suggest the similarity of the data collected from these two measurements. Photoluminescence (PL) spectra demonstrated increased luminescence amplitude with increased Ni concentration. Thus, the present study determines the time required for 4-nitrophenol yellow to colorless by Ni-doped Mn₃O₄ and Mn₃O₄ samples.     

Chemical solution deposited thin films of titanium,chromium, zirconium,and tin oxides

TiO₂, Cr₂O₃, ZrO₂, and SnO₂ films with thicknesses of ～10–100 nm were produced via dipping into solution and subsequent annealing in air. The films were studied by the methods of scanning electron microscopy, elemental X-ray spectral analysis, optical spectroscopy, and X-ray diffraction. The electrical conductivity of the films in air and in a vacuum was measured. The adhesion of most of the films to the substrate was found to be high. A crystalline structure was observed for films thicker than 10 nm. The films have a specific surface resistance of 10⁸–10¹² Ω in air and 10⁹–10¹⁴ Ω in a vacuum. The films are promising as coatings for various purposes, including the development of structures of the core–shell type.     

Magnetic materials containing LaSr manganite phase

Ferromagnetic glass–crystalline materials were produced by sintering of glasses from the systems Bi₂O₃B₂O₃MnO and crystalline phase La_0.6Sr_0.4MnO₃. The appropriate preparation procedure was applied as follows: synthesis of the starting components, mixing, milling, pressing and sintering at selected temperatures. The steps of the technological scheme were controlled by X-ray diffraction and infrared spectroscopy. Small crystals with size in the order of 1–5 μm were detected by transmission electron microscopy observations [TEM] after heath treatment. The magnetic properties were studied by a vibrating sample magnetometer [VSM] and the Curie temperature was detected at 353 K. The presence of a narrow hysteresis loop proves the ferromagnetic properties of the materials.     

La6(BN3)O6, ein Nitridoborat‐Oxid des Lanthans

La₆(BN₃)O₆, a Nitridoborate Oxide of Lanthanum Single‐crystals of La₆(BN₃)O₆ were formed in reactions of Li₃BN₂, Li₃N, and LaOCl at 950 °C. The structure was solved by single‐crystal X‐ray diffraction. La₆(BN₃)O₆crystallizes with the space group Cmcm (no. 63) containing Z = 4 formula units in the unit cell, with lattice parameters of a = 366.88(3) pm, b = 2509.2(3) pm, and c = 1101.1(1) pm (R1 = 0.054, wR2 = 0.065 for all collected symmetry independant reflections). The crystal structure reflects typical patterns obtained in structures of nitridoborates. Tri‐nitridoborate ions are coordinated by La³⁺ ions in a tricapped trigonal prismatic arrangement, being stacked via shared trigonal faces to form columns. The arrangement of the columns in the structure provides space for O^2— ions with CN = 4, 5, and 6.     

A new technique for the synthesis of lanthanum substituted nickel cobaltite nanocomposites for the photo catalytic degradation of organic dyes in wastewater

Developing cost-effective and more efficient nanocatalysts for the treatment of organic pollutants from process industry is always challenging for the researchers working in the field of chemistry, chemical, energy and environment engineering. In this work, a cost-effective and more efficient nanocatalysts, i.e., Nickel Cobaltite nanocomposites and its Lanthanum (La) doped derivatives with controlled surface morphology has been synthesized at 393.15 K through single step sol–gel method. The surface morphology, chemical composition, and crystal structure of the synthesized nanocomposites were analysed by scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), and X-rays diffraction (XRD), respectively. The rough surface and well-crystallized metallic nanocomposites confirm the successful synthesis of nanocatalysts. The molar ratio of Lanthanum to Cobalt (La_x:Co_y) showed a significant influence on the surface morphology and catalytic activity (K_app = 0.15–0.47 min⁻¹) of the products. Synthesized nanocomposites showed high catalytic activity for the reduction of methylene blue under solar irradiation. Photocatalytic results for the reduction of methylene blue show that the catalytic activity of synthesized nanocatalysts increases with the increase in the doping concentration of Lanthanum.     

ß‐Ga2O3 Nanorod Synthesis with a One‐step Microwave Irradiation Hydrothermal Method and its Efficient Photocatalytic Degradation for Perfluorooctanoic Acid

ß‐Ga₂O₃ nanorod was first directly prepared by the microwave irradiation hydrothermal way without any subsequent heat treatments, and its characterizations were analyzed by X‐ray diffraction (XRD), scanning electron microscope (SEM), high‐resolution transmission electron microscope (HRTEM), UV–Vis diffuse reflection spectroscopy techniques, and also its photocatalytic degradation for perfluorooctanoic acid (PFOA) was investigated. XRD patterns revealed that ß‐Ga₂O₃ crystallization increased with the enhancement of microwave power and the adding of active carbon (AC). PFOA, as an environmental and persistent pollutant, is hard decomposed by hydroxyl radicals (HO·); however, it is facilely destroyed by ß‐Ga₂O₃ photocatalytic reaction in an anaerobic atmosphere. The important factors such as pH, ß‐Ga₂O₃ dosage and bubbling atmosphere were researched, and the degradation and defluorination was 98.8% and 56.2%, respectively. Reductive atmosphere reveals that photoinduced electron may be the major reactant for PFOA. Furthermore, the degradation kinetics for PFOA was simulated and constant and half‐life was calculated, respectively.     

Synthesis,design of experiments and optimization of heterogeneous Fenton-like degradation of tartrazine by MgFe2O4 nano-catalyst

In this work, magnesium ferrites nanoparticles (MgFe₂O₄ NPs) were successfully fabricated by sol-gel auto-combustion (SGAC) method and were used in heterogeneous Fenton-like degradation of tartrazine. The obtained products were characterized using XRD, FTIR, SEM and EDX. XRD studies confirmed that the synthesized MgFe₂O₄ NPs had a cubic spinel structure. The average crystallite size was evaluated using the Debyee Scherrer formula and found to be in the range 16.18–28.55 nm. In FTIR spectra, two primary absorption bands at 571 cm^?1 and 415 cm^?1 were observed. The spinel ferrites are characterized by these bands and the EDX confirms the presence of the desired elements Mg, Fe, and O. The influences of operating parameters were examined using the Box Behnken statistical design (BD), including magnesium ferrite dosage (0.04–0.12 g/L), tartrazine concentration (30–50 mg/L) and H₂O₂ concentration (3.53–7.06 mM). Using analysis of variance, a significant quadratic model was created. Optimum conditions were magnesium ferrite dosage of 0.092 g/L, tartrazine concentration of 30.21 mg/L and H₂O₂ concentration of 6.66 mM, respectively. The predicted degradation efficiency within the optimum conditions as established by the suggested model was 98.4%. Confirmatory tests were carried out and the degradation efficiency of 98.9% was observed, which was in good agreement with the model's prediction. After five recuperation and reapplications, the catalyst's degradation efficiency remains stable. These findings indicate that a heterogeneous Fenton-like process utilizing MgFe₂O₄ is effective in advanced wastewater treatment.     

Effects of lithium insertion and deinsertion into V2O5 thin films: Optical,structural, and absorption properties

The lithiated/delithiated vanadium pentoxide films deposited by sol‐gel spin coating on indium tin oxide–coated glass substrates were analyzed by sputter‐induced photon spectroscopy, X‐ray diffraction, and optical absorption techniques. First, it is shown that the crystalline structure of V₂O₅ after intercalation remains practically unchanged. Particularly, in the optical spectra during 5 keV Kr⁺ ion bombardment of clean, intercalated, and deintercalated V₂O₅ films, a series of sharp lines and unexpected continuum radiation were observed and well explained. It is also demonstrated that the intercalation and deintercalation of lithium have strong influences on various characteristics of pentoxide vanadium. The interpretations of the obtained results in the 3 experiments—X‐ray diffraction, sputter‐induced photon spectroscopy, and optical absorption techniques—are coherent and complement each other.     

Investigation of opto-dielectric properties of Ti-doped Ga2O3 thin films

Several Ti-incorporated Ga-oxide (Ga₂O₃) thin films with different amounts of Ti contents have been prepared by vacuum evaporation method on glass and silicon substrates. The Ti incorporation level was measured with energy dispersion X-ray spectroscopy (EDX) method. The crystalline structure of the prepared films was determined with X-ray diffraction method. Experimental data indicate that Ti⁴⁺ ions doped in host Ga₂O₃ form solid solutions (SS) even with so large Ti% content ∼10.4% wt. All the prepared solid solutions have the known orthorhombic (ɛ-phase) phase of Ga₂O₃. The doping controls the optical and electrical properties of the host Ga₂O₃. It was found that the bandgap of the prepared undoped Ga oxide is 5.23 eV, which was decreased monotonically with increasing of Ti doping level so that it is possible to engineer the bandgap. Furthermore, the electrical measurements show that with Ti doping, it is possible to turn the high-k Ga oxide into low-k dielectric material. The optical sensitivity of the capacitance, dissipation factor, and ac-conductance of the Ga₂O₃:Ti films grown on Si was studied as a function of Ti-doping level. It was observed that the prepared Ga₂O₃:Ti film with 6–10% doping level has the highest photosensitivity among the other samples.     

Formation and decomposition of Lanthanum Monoxocarbonate

Amorphous lanthanum carbonate was prepared by hydrolysis of lanthanum isopropoxide using ammonia water in the atmosphere. Lanthanum monoxocarbonate, La₂O(CO₃)₂ · H₂O, crystallizes when this amorphous material was washed with hot water. The crystallization and thermal behavior of the crystalline material are studied by X-ray diffraction, thermal analysis, and infrared spectroscopy. The decomposition of La₂O(CO₃)₂ · H₂O into type-IA (LaO)₂CO₃ is observed at 440 to 540°C. Decomposition isotherms are described by the contracting cube equation, the activation energy being 42.6 kcal mol^?1. Type-IA (LaO)₂CO₃ subsequently decomposes to A-type La₂O₃ at 750 to 870°C. The kinetics is also interpreted in terms of the contracting cube equation, the activation energy being 58.3 kcal mol^?1.     

Photocatalytic degradation of azophloxine on porous La2Ti2O7 prepared by sol-gel method

Cetyltrimethyl ammonium bromide (CTAB) was used in a sol-gel route to synthesize porous lanthanum titanate. The materials are composed of perovskite La₂Ti₂O₇ in monoclinic system. The addition of CTAB does not cause phase transformation, but leads to a slight decreasing tendency of La₂Ti₂O₇ crystallite size. Both the pore volume and pore size distribution range are enlarged after using CTAB. The sample obtained with 4 g CTAB has the maximum BET specific surface area of 42.4 m²/g. When the amount of CTAB is less than 4 g, the increase in photocatalytic degradation efficiency is almost in linear relationship to the amount of CTAB. The reaction rate constants are 0.0032, 0.0116 and 0.0237 min⁻¹ on the La₂Ti₂O₇ samples obtained using 0, 2 and 4 g CTAB. The functional groups in azophloxine molecule are decomposed during photocatalytic oxidation with extending irradiation time.     

Comparison of photocatalytic and antibacterial activities of allotropes of graphene doped Sm2O3 nanocomposites: Optical,thermal, and structural studies

This study mainly focuses on the synthesis of two allotropes of graphene, graphene oxide (GO) and reduced graphene oxide (rGO), by the modified Hummers' method and chemical reduction method, respectively. Sm₂O₃/GO and Sm₂O₃/rGO nanocomposites were further synthesized in the presence of the cationic surfactant CTAB via the sol–gel method followed by the reflux method. Synthesized nanocomposites were subjected to characterization by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and UV–Visible spectroscopy to explore structural, thermal, optical, and photocatalytic properties. Characteristic FTIR peaks were observed in nanocomposites, and the bond length of the Sm-O bond was calculated. The Coats-Redfern method was employed to calculate the kinetics and thermodynamic parameters. Hexagonal crystallite shapes of Sm₂O₃/GO and Sm₂O₃/rGO nanocomposites with 11.8 and 13.13 nm crystallite sizes and 3.9 and 2.5 eV optical band gaps were observed. The photocatalytic efficiency of Sm₂O₃/GO and Sm₂O₃/rGO nanocomposites was assessed against the degradation of methylene blue in the presence of sunlight, and its degradation was confirmed through FTIR. The antimicrobial activities were also performed against the bacterial strains Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.     

经Opuntia dilenii haw植物提取液绿色合成制备的纳米铝酸锌的催化性质(英文)

Various nanosized zinc aluminate(ZnAl2O4) samples were prepared by a conventional and a mi- crowave method both with and without using Opuntia dilenii haw plant extract,and were charac- terized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),high resolution scanning electron microscopy(HRSEM),energy dispersion scanning(EDX),temperature dependent conductance measurements, thermoelectric power measurements, ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy,and photoluminescence spectroscopy.The formation of a pure ZnAl2O4 phase was confirmed by XRD and FT-IR.A change in morphology from nanosized plates to nanosized sheets with,respectively,the conventional and microwave heating methods was clearly shown by HRSEM.UV-Vis diffusion reflectance spectroscopy measured the band gaps of ZnAl2O4 nanosized plates and nanosized sheets as 3.5 and 3.9 eV,respectively.The synthesized ZnAl2O4 was single crystalline and has three photoluminescence emissions at 482,528,and 540 nm.ZnAl2O4 nanosized sheets prepared by the microwave method showed higher catalytic activity for the oxida- tion of benzyl alcohol(85% conversion) than ZnAl2O4 nanosized plates prepared by the convention- al method(60% conversion).     

Chemical deposition of zirconium doped tin silicate ion-exchanger and its characterization

Doping of inorganic ion-exchange material tin silicate with zirconium ion by sol-gel technique was conducted for the production of a novel ion-exchanger. Undoped and doped tin silicate has been characterized by elemental analysis (X-ray fluorescence), Fourier transform infrared spectroscopy (FT-IR), thermal analysis and X-ray diffraction studies. The structures of two ion-exchangers were identified and the empirical formulas found as SnSi₂O₆·6H₂O and SnZr₄Si₄O₁₂·16H₂O for tin silicate and zirconium doped tin silicate, respectively. The effect of zirconium ion concentration of the doped tin silicate on the crystalline size and strain of tin silicate was investigated. The probable structure of both materials was assessed by the ChemDraw Ultra program. Finally, application of these materials for the treatment of radionuclides in terms of capacity measurements was investigated.     

Flash microwave synthesis and sintering of nanosized La0.75Sr0.25Cr0.93Ru0.07o3-δ for fuel cell application

Perovskite-oxide nanocrystals of La_0.75Sr_0.25Cr_0.93Ru_0.07O_3-δ with a mean size around 10 nm were prepared by microwave flash synthesis. This reaction was performed in alcoholic solution using metallic salts, sodium ethoxide and microwave autoclave. The obtained powder was characterised after purification by energy dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), BET adsorption technique, photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM). The results show that integrated perovskite-type phase and uniform particle size were obtained in the microwave treated samples. At last the synthesised powder was directly used in a sintering process. A porous solid, in accordance with the expected applications, was then obtained at low sintering temperature (1000 °C) without use of pore forming agent.     

Growing kinetics and structural characterization of oxide film formed on La-doped Co-40Cr alloy

The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM)) were used to examine the oxidized film's morphology and the structure after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by La-doping and its in?uence on formation of Cr2O3 film. Laser Raman spectrum was used to examine the tress changes within oxidized films. It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co-40Cr and improved the anti-cracking and anti-spalling properties of Cr2O3 film. The reasons were that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide, increased the high temperature plasticity of oxidized film. Lanthanum mainly existed in the outer surface of Cr2O3 film in the forms of fine La2O3 and LaCrO3 spinel particles.