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1.
BMC Gastroenterol ; 24(1): 42, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38254056

RESUMO

BACKGROUND/AIMS: Upper gastrointestinal bleeding (UGIB) is a frequent medical issue. The primary risk factors for bleeding peptic ulcers are Helicobacter pylori infection and non-steroidal anti-inflammatory drugs. The association between acute gastric/duodenal ulcer and opium use has been previously proposed; however, there is no available data on endoscopic findings of patients with acute UGIB who use opium. MATERIALS AND METHODS: In the present descriptive cross-sectional study, endoscopic data of 50 consecutive patients with oral opium use and 50 consecutive patients without any opium use who were admitted for UGIB were recorded. The size (5-10 mm, 11-20 mm, or more than 20 mm), number (single, double, or multiple), and location of the ulcers (esophagus, gastric corpus including the fundus and body, antrum, angulus, or duodenum) were examined by endoscopy in both groups. RESULTS: Three or more ulcers were observed in 46% and 16% of patients with oral opium use and without opium use, respectively (P-value = 0.001). The rate of giant ulcers (> 20 mm) was significantly higher in patients who used oral opium (40% vs. 12%; P-value = 0.007). Esophageal ulcers were also more common in oral opium users (30%) than non-users (8%) with UGIB (P-value = 0.01). Nevertheless, the location of the ulcers between the two groups generally was not statistically different. CONCLUSIONS: This study has demonstrated that multiple, large peptic ulcers in GIB are potential complications of oral opium use. This could aid the needed modifications in the treatment protocol for these patients.


Assuntos
Úlcera Duodenal , Infecções por Helicobacter , Helicobacter pylori , Dependência de Ópio , Úlcera Péptica , Úlcera Gástrica , Humanos , Ópio/efeitos adversos , Úlcera , Estudos Transversais , Infecções por Helicobacter/complicações , Úlcera Péptica/complicações , Hemorragia Gastrointestinal/induzido quimicamente , Úlcera Duodenal/complicações , Úlcera Gástrica/complicações
2.
Phys Chem Chem Phys ; 25(32): 21336-21349, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37529865

RESUMO

In this study, hexagonal boron nitride (BN) with a sheet-like morphology is successfully synthesized by reacting borax (Na2B4O7·10H2O) and urea (CO(NH2)2) powders in air via a facile microwave-assisted method within a short reaction time (15 min). The as-prepared product is structurally characterized via Fourier transformation infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersion X-ray analyzer (EDX), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) surface area measurements. The adsorption process of methyl violet (MV) as a model of organic dyes and ciprofloxacin (CIP) as a model of antibiotics onto the boron nitride nanosheets has been experimentally and theoretically studied. The BN nanosheets exhibit the maximum adsorption capacity of 320.94 mg g-1 for MV dye and 266.29 mg g-1 for CIP antibiotic. The Freundlich isotherm model was suitable to describe the adsorption equilibrium isotherm data and the pseudo second-order model reflected the adsorption kinetics well. The calculated thermodynamic parameters show that the adsorption process is spontaneous under the measured conditions. The adsorption of CIP, MV and CIP + MV molecules on the surface of BN has been investigated through DFT calculations. The charge transfer and high adsorption capacity demonstrate the potential of BN nanosheets as an adsorbent for the simultaneous removal of MV dye and CIP drug from contaminated water.

3.
Langmuir ; 35(34): 11188-11199, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31373498

RESUMO

Herein, in a new approach, highly porous alumina materials (HiPAs) have been synthesized through cetyltrimethylammonium bromide (CTAB) bloated micelles or merged CTAB/dicarboxylic acid vesicular aggregates (di-acids with 8, 10, and 12 carbon atoms) as novel templates and characterized by N2 sorption, low- and wide-angle XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy), TEM (transmission electron microscopy), HR-TEM (high-resolution transmission electron microscopy), DLS (dynamic light scattering), and AFM (atomic force microscopy) analyses. In the absence of dicarboxylic acids, CTAB bloated micelles in ethanol-aqueous solutions were conductive to the formation of mesoporous γ-alumina hollow spheres (HiPA-CT) with high surface area (394 m2 g-1) and ultralarge pore volume (1.8 cm3 g-1). Notably, merged giant vesicular assemblies formed between dicarboxylic acids and CTAB endowed the mesoporous alumina nanoparticle aggregates with tunable and unprecedented pore features (surface area of 415-735 m2 g-1 and ultrahigh pore volume of 1.37-2.57 cm3 g-1), in which their pinnacle was obtained via CTAB/10 (HiPA-CT-10). Due to the tailored porosity, the HiPA-CT and HiPA-CT-10 were exploited for ciprofloxacin (CIP) adsorption experiments. The adsorption efficiency attained a climax at pH 6. At CIP concentrations below 1 ppm, 91 and 86% of CIP were removed by HiPA-CT and HiPA-CT-10, respectively. The maximum adsorption capacities of HiPA-CT and HiPA-CT-10 are 120 and 184 mg g-1, respectively, in which the latter is surpassing those of inorganic antibiotic adsorbents reported so far. The kinetic results showed that the removal of CIP by HiPA-CT was faster due to the presence of macropores and more accessible active sites on mesoporous surfaces. The reusability test was acceptable after eight runs. The results signify that these novel materials have high potential for reducing our environmental concerns.

4.
Acta Chim Slov ; 65(2): 448-461, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29993113

RESUMO

Novel magnetically separable Bi2O2CO3/CoFe2O4 nanocomposites were fabricated by a feasible hydrothermal route. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), vibrating sample magnetometer (VSM), and N2 adsorption-desorption analysis were employed to examine the structure, morphology, particle size, phase composition, optical and magnetic properties of the as-synthesized nanocomposites. The results of the findings showed demonstrated the successful coupling of spherical CoFe2O4 nanoparticles and plate-like Bi2O2CO3 nanostructures. The catalytic performance of magnetic Bi2O2CO3/CoFe2O4 nanocamposites was evaluated in the reduction of some aromatic nitrocompounds such as nitrophenols and nitroanilines by using sodium borohydride (NaBH4) aqueous solution at room temperature. The Bi2O2CO3/CoFe2O4 nanocamposite with 30 %wt. CoFe2O4 exhibited the best performance in the reduction of aromatic nitrocompounds with 100% conversion into the corresponding amino compounds within 15-30 min with rate constant of 0.10-0.24 min-1. The effect of catalyst dosage was also investigated on the efficiency of reduction process. Furthermore, magnetic Bi2O2CO3/CoFe2O4 nanocomposite could be easily removed by an external magnet from the reaction system.

5.
Acta Chim Slov ; 64(4): 1005-1019, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29318291

RESUMO

In this study, the PMo12O403- polyanion was immobilized chemically on amino functionalized magnetic graphene oxide nanosheets. The as-prepared ternary magnetic nanocomposite (Fe3O4/GO-NH2/H3PMo12O40) was characterized by powder X-ray powder diffraction (XRD), fourier transformation infrared spectroscopy (FTIR), Raman spectroscopy, energy dispersive spectroscopy (EDX), field emission scanning electron microscopy (FESEM), BET surface area measurements, magnetic measurements (VSM) and atomic force microscopy (AFM). The results demonstrated the successful loading of H3PMo12O40 (~36.5 wt.%) on the surface of magnetic graphene oxide. The nanocomposite showed a higher specific surface area (77.07 m2/g) than pure H3PMo12O40 (≤10 m2/g). The adsorption efficiency of this nanocomposite for removing methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) from aqueous solutions was evaluated. The nanocomposite showed rapid and selective adsorption for cationic dyes from mixed dye solutions. The adsorption rate and capacity of Fe3O4/GO-NH2/H3PMo12O40 were enhanced as compared with GO, GO-NH2, Fe3O4/GO-NH2, and H3PMo12O40 samples due to enhanced electrostatic attraction and hydrogen-bonding interactions. The nanocomposite is magnetically separated and reused without any change in structure. Thus, it could be a promising green adsorbent for removing organic pollutants in water.

6.
Acta Chim Slov ; 64(4): 945-958, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29318306

RESUMO

In this work, graphene oxide/Co3O4 nanocomposite was synthesized via hydrothermal decomposition of [Co(en)3] (NO3)3 complex onto graphene oxide nanosheets. The as-prepared nanocomposite (denoted as GO/Co3O4) was structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopies (TEM and SEM), energy dispersive X-ray (EDX) spectroscopy, magnetic measurements, and N2 adsorption-desorption analysis. The results demonstrated successful immobilization of Co3O4 nanoparticles with an average diameter size of around 12.5 nm on the surface of graphene oxide nanosheets. The adsorption performance of GO/Co3O4 nanocomposite was investigated towards different organic dyes in aqueous solutions. The results displayed that the adsorption rate of the GO/Co3O4 nanocomposite was 98% for methylene blue (MB) in 12 min, and 66% and 45% for Rhodamine B (RhB) and methyl orange (MO) in 40 min, respectively. The effects of various important parameters including adsorbent dosage, contact time, pH, and temperature on the adsorption process were investigated in detail. The equilibrium adsorption data were better fitted by Langmuir isotherm. Adsorption kinetics is well-modeled using pseudo-second-order model. Different thermodynamic parameters indicated that the adsorption process was physisorption and spontaneous. The findings of the present work highlighted facile fabrication of GO/Co3O4 and its application for rapid and efficient removal of MB from wastewater.

7.
Acta Chim Slov ; 64(1): 129-143, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28380222

RESUMO

In this work, we have synthesized spherical silver nanoparticles (Ag NPs) by a low-cost, rapid, simple and ecofriendly approach using Date palm fruit extract as a novel natural reducing and stabilizing agent. The product was characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), energy-dispersive X-ray (EDX) spectroscopy and Zeta potential measurements. The reaction conditions including time, content of reducing agent and silver nitrate, temperature and pH were investigated. The optimum yield of Ag NPs was obtained when 10 mM of silver nitrate was reacted with Date fruit extract at pH 11 and heated it to 55 °C within 10 minutes. The elemental and crystalline nature of Ag NPs were confirmed from EDX and XRD analysis. SEM and TEM images showed that the Ag NPs were spherical and with sizes in the range of 25-60 nm. On the base of FT-IR analysis, it can be stated that the functional groups present in bio-molecules of Date fruits are responsible for the reduction and stabilization of Ag NPs, respectively. The Ag NPs showed good antibacterial activity against a few human pathogenic bacteria. The catalytic activity of the Ag NPs for rapid and efficient reduction of toxic nitro compounds into less toxic corresponding amines by using NaBH4 was also investigated.


Assuntos
Antibacterianos/farmacologia , Nanopartículas Metálicas , Phoeniceae/química , Extratos Vegetais/farmacologia , Prata/química , Antibacterianos/química , Catálise , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Microscopia/métodos , Extratos Vegetais/química , Análise Espectral/métodos
8.
RSC Adv ; 14(16): 11037-11056, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38586447

RESUMO

In this study, MoS2/NiFe2O4/MIL-101(Fe) nanocomposite was synthesized by hydrothermal method and used as an adsorbent for the elimination of organic dyes and some antibiotic drugs in aqueous solutions. The synthesized nanocomposite underwent characterization through different techniques, including scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) surface area analysis, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), zeta potential analysis, vibrating sample magnetometry (VSM), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). These results demonstrated the successful insertion of MoS2within the cavities of MIL-101(Fe). The as-prepared magnetic nanocomposite was used as a new magnetic adsorbent for removing methylene blue (MB) and rhodamine B (RhB) organic dyes and tetracycline (TC) and ciprofloxacin (CIP) antibiotic drugs. For achieving the optimized conditions, the effects of initial pH, initial dye and drug concentration, temperature, and adsorbent dose on MB, TC, and CIP elimination were investigated. The results revealed that at a temperature of 25 °C, the highest adsorption capacities of MoS2/NiFe2O4/MIL-101(Fe) for MB, TC, and CIP were determined to be 999.1, 2991.3, and 1994.2 mg g-1, respectively. The pseudo-second-order model and Freundlich model are considered suitable for explaining the adsorption behavior of the MoS2/NiFe2O4/MIL-101(Fe) nanocomposite. The magnetic nanocomposite was very stable and had good recycling capability without any change in its structure.

9.
RSC Adv ; 13(10): 6356-6367, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36845582

RESUMO

In this work, a magnetic H3PW12O40/Fe3O4/MIL-88A (Fe) rod-like nanocomposite as a stable and effective ternary adsorbent was fabricated by the hydrothermal method and utilized for the removal of ciprofloxacin (CIP), tetracycline (TC) and organic dyes from aqueous solution. Characterization of the magnetic nanocomposite was accomplished by FT-IR, XRD, Raman spectroscopy, SEM, EDX, TEM, VSM, BET specific surface area and zeta potential analyses. The influencing factors on the adsorption potency of the H3PW12O40/Fe3O4/MIL-88A (Fe) rod-like nanocomposite including initial dye concentration, temperature and adsorbent dose were studied. The maximum adsorption capacities of H3PW12O40/Fe3O4/MIL-88A (Fe) for TC and CIP were 370.37 mg g-1 and 333.33 mg g-1 at 25 °C, respectively. In addition, the H3PW12O40/Fe3O4/MIL-88A (Fe) adsorbent had high regeneration and reusability capacity after four cycles. In addition, the adsorbent was recovered through magnetic decantation and reused for three consecutive cycles without a considerable reduction in its performance. The adsorption mechanism was mainly ascribed to electrostatic and π-π interactions. According to these results, H3PW12O40/Fe3O4/MIL-88A (Fe) can act as a reusable effective adsorbent for the fast elimination of tetracycline (TC), ciprofloxacin (CIP) and cationic dyes from aqueous solutions.

10.
RSC Adv ; 13(16): 10940-10955, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37033431

RESUMO

A novel magnetic g-C3N4/CoFe2O4 nanocomposite was successfully synthesized by a simple hydrothermal method and applied as a new graphene-like carbon nitride-based sonocatalyst for sonodegradation of pollutant dyes. The as-prepared samples were characterized by using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (DRS), BET surface area measurements and photoluminescence (PL) spectroscopy. The results indicate that the nanocomposite sample is composed of spherical CoFe2O4 nanoparticles adhered to g-C3N4 naosheets. The g-C3N4/CoFe2O4 nanocomposites were used as a new magnetically separable sonocatalyst in H2O2-assisted sonodegradation of methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) dyes in aqueous media. The results showed complete degradation (ca. 100%) of dyes within short times (30-35 min). The sonocatalytic activity of graphitic carbon nitride (g-C3N4) was greatly enhanced with CoFe2O4 modification. Trapping experiments indicated that the g-C3N4/CoFe2O4 nanocomposites serves as a generator of hydroxyl radical (˙OH) via activation of H2O2 for degradation of dyes under ultrasound irradiation. Furthermore, the magnetic sonocatalyst can be separated from solution by an external magnet and reused several times without observable loss of activity. The possible mechanism of sonocatalytic activity was also proposed according to experimental results.

11.
RSC Adv ; 13(20): 13683-13697, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37152578

RESUMO

A rod-like magnetic nanocomposite was successfully synthesized in this work by loading Ag and Fe3O4 nanoparticles onto the surface of the hydroxyapatite/MIL-101(Fe) metal-organic framework. Various techniques were used to investigate the crystalline nature, size, morphology, and magnetic and structural properties of the HAP/MIL-101(Fe)/Ag/Fe3O4 nanocomposite, including X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), BET surface area measurements, and zeta potential analysis. The results indicate that the nanocomposite sample is composed of Ag and Fe3O4 nanoparticles adhered to rod-like hydroxyapatite/MIL-101(Fe). The catalytic and antibacterial abilities of the as-prepared HAP/MIL-101(Fe)/Ag/Fe3O4 were studied. This nanocomposite was utilized as a heterogeneous catalyst for the catalytic reduction of toxic pollutants, including 4-nitrophenol (4-NP), 2-nitrophenol (2-NP), 2,4-dinitrophenol (2,4-NP), 4-nitroaniline (4-NA), and 2-nitroaniline (2-NA) by NaBH4 in water and at room temperature. These compounds were converted to their amine derivatives within 8-18 min with rate constant values equal to 0.2, 0.3, 0.33, and 0.47 min-1, respectively. This quaternary magnetic catalyst can be easily separated from the reaction medium using an external magnetic field and reused. The synthesized nanocomposite maintained its efficiency in reducing nitroaromatic compounds after 5 runs, showing the high stability of the catalyst. Besides, the antibacterial activity of the nanocomposite against Gram-negative and Gram-positive bacteria was evaluated using the disk diffusion method. The inhibition zone diameter of the nanocomposite against Staphylococcus aureus, Staphylococcus saprophyticus, and Escherichia coli was measured to be 17, 14, and 12 mm, respectively.

12.
RSC Adv ; 12(53): 34438-34453, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36545621

RESUMO

A novel porous nanocomposite composed of hydroxyapatite nanorods (HAP), a MIL-101(Fe) metal-organic framework, and Fe3O4 nanoparticles was successfully fabricated in this work. The magnetic HAP/MIL-101(Fe)/Fe3O4 ternary nanocomposite was identified by various techniques, namely FT-IR spectroscopy, XRD, Raman spectroscopy, SEM, EDX, TEM, BET specific surface area, zeta potential, and VSM measurements. Tetracycline (TC) and ciprofloxacin (CIP) aqueous solutions were used to evaluate the adsorption performance of the resulting HAP/MIL-101(Fe)/Fe3O4 composite. The adsorption rate and capacity of HAP/MIL-101(Fe)/Fe3O4 were increased as compared with HAP, MIL-101(Fe), and HAP/MIL-101(Fe) samples due to the increased attraction. The influence of initial drug concentration, adsorbent dosage, temperature, and pH on the adsorption process was investigated. The results showed that the removal efficiencies of HAP/MIL-101(Fe)/Fe3O4 for TC and CIP were 95% and 93%, under the determined optimum conditions: pH of 7, drug concentration of 50 mg L-1, adsorbent dosage of 30 mg, and temperature of 25 °C. The maximum adsorption capacities of HAP/MIL-101(Fe)/Fe3O4 for TC and CIP were 120.48 mg g-1 and 112.35 mg g-1, respectively. Reusability of the prepared nanocomposite was easily achieved up to three times without significant change in its structure. As a result, the synthesized magnetic nanocomposite can be reused as a suitable absorbent for TC and CIP removal from aqueous solutions.

13.
Food Chem ; 373(Pt A): 131423, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-34700035

RESUMO

A new hybrid of silica aerogel with a Preyssler-type polyoxometalate and MIL-101(Cr) metal-organic framework was prepared and used as a highly porous fiber coating for headspace solid-phase microextraction of Ferulago angulata volatile components. Applying a permanent magnetic field to the sorbent increased the extraction efficiency for most of the plant's components, up to 5.53 times. Optimization of the extraction parameters was carried out using a GC-MS instrument and by a simplex method. The extraction efficiency of the P5W30/MIL-101(Cr)/silica aerogel fiber exceeded 3.5 times of a mesoporous SBA-15 fiber. The prepared fiber was stable in multiple injections with relative standard deviations of 5.3 to 10.9% for 5 replicates. The proposed method was successfully applied to the extraction and identification of volatile components of some F. angulata samples. According to the results obtained by GC-FID, ß-bourbonene, ß-gurjunene, ß-elemene and cedrenol were the main components of the plant.


Assuntos
Estruturas Metalorgânicas , Ânions , Fenômenos Magnéticos , Polieletrólitos , Dióxido de Silício , Microextração em Fase Sólida
14.
RSC Adv ; 10(65): 39881-39893, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-35515376

RESUMO

In this study, the MIL-101(Cr) metal-organic framework was functionalized with a Dowson-type polyoxometalate (P2W18O62 6-; POM) and magnetic spinel cobalt ferrite (CoFe2O4; CFO) through a hydrothermal route and was characterized by means of FT-IR, XRD, FE-SEM, EDX, BET, and VSM measurements. All analyses confirmed the successful encapsulation of POM (∼32.2 wt%) into the magnetic MIL-101(Cr) framework. Compared to the pristine MIL-101(Cr) MOF, the as-prepared magnetic ternary nanocomposite (abbreviated as POM/CFO/MIL-101(Cr)) demonstrated a notable decrease in both the surface area and pore volume because of the incorporation of CoFe2O4 nanoparticles and huge P2W18O62 6- polyanions into the cages of the MIL-101(Cr) framework. The POM/CFO/MIL-101(Cr) was then applied as a magnetically separable adsorbent for the rapid elimination of rhodamine B (RhB), methyl orange (MO), and methylene blue (MB) dye pollutants from aqueous solutions. For achieving the optimized conditions, the effects of initial pH, initial dye concentration, temperature, salt effect, and adsorbent dose on MB and RhB elimination were investigated. The dye adsorption isotherms followed the Langmuir model and pseudo-second-order kinetic model. The POM/CFO/MIL-101(Cr) composite material not only exhibited a fast adsorption rate towards dye molecules, but also demonstrated the selective adsorption of the cationic dyes in wastewater. The recycling experiments also demonstrated that the POM/CFO/MIL-101(Cr) adsorbent was highly stable and could be quickly recovered under a magnetic field without any alteration in the structure. The high adsorption capacity, simple fabrication method, rapid separation by a magnet and supreme reusability of the POM/CFO/MIL-101(Cr) nanocomposite make it an attractive adsorbent for the elimination of cationic dyes from wastewater.

15.
RSC Adv ; 10(17): 10082-10096, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-35498565

RESUMO

In this research, a novel magnetic sonocatalyst nanocomposite, CoFe2O4@Cr-MIL-101/Y zeolite, has been successfully fabricated employing a simple hydrothermal method. The as-prepared catalyst was thoroughly identified using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), EDS elemental dot-mapping, transmission electron microscopy (TEM), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), and nitrogen Brunauer-Emmett-Teller (N2-BET) analyses. The procured CoFe2O4@Cr-MIL-101/Y nanocomposite was then assessed for the decomposition of three types of organic dyes namely methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) from water solution using ultrasound irradiation and subsequently monitored via UV-Vis absorption technique. The sonodecomposition reactions of organic dyes were accomplished in the presence of the H2O2 solution as a green oxidizing agent. Furthermore, the influence of various experimental independent factors such as irradiation time, process type, initial dye concentration, catalyst dosage, H2O2 concentration, scavenger type, and catalyst regeneration on the decomposition of MB, RhB and MO were surveyed. Additionally, a first order kinetic model was applied to investigate the sonodecomposition reactions of dye contaminants. The rate constant (k) and half-life (t 1/2) data were gained as 0.0675 min-1 and 10.2666 min, respectively, for the decomposition of MB in the US/H2O2/CoFe2O4@Cr-MIL-101/Y system. Besides, evaluating the attained results, the distinctive performance of ˙OH as the radical scavenger originating from H2O2 throughout the sonodecomposition process is vividly approved.

16.
RSC Adv ; 10(72): 44034-44049, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-35517154

RESUMO

In this work, the novel magnetically separable NaY zeolite/MgFe2O4/CdS nanorods/MoS2 nanoflowers nanocomposite was successfully synthesized through the ultrasonic-assisted solvothermal approach. FESEM, EDAX, XRD, FTIR, TEM, AFM, VSM, N2-BET, UV-vis DRS and PL were utilized to identify the as-synthesized nanocomposite. Subsequently, the sonocatalytic activity of this nanocomposite was assessed in the degradation of organic dyes, including methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) from water solutions for the first time. Several analytical parameters like irradiation time, process type, initial MB concentration, H2O2 concentration, catalyst dosage, organic dye type, and US power have been systematically investigated to attain the maximum sonocatalytic yield. Regarding the acquired data, the NaY/MgFe2O4/CdS NRs/MoS2 NFs sonocatalyst was incredibly able to completely eliminate the MB via engaging the US/H2O2 system. The kinetic evaluates demonstrated the sonodegradation reactions of the MB followed a first-order model. The apparent rate constant (k app) and half-life time (t 1/2) acquired for the sonodegradation process of MB utilizing the US/H2O2/NaY/MgFe2O4/CdS NRs/MoS2 NFs system were measured to be 1.162 min and 0.596 min-1, respectively. The free ˙OH radicals were also recognized as the main reactive oxygen species in the MB sonodegradation process under US irradiation. In addition, the outcomes of the recyclability study of the NaY/MgFe2O4/CdS NRs/MoS2 NFs sonocatalytic clearly displayed a less than 6% drop of the catalytic activity in up to four sequential runs. Lastly, a plausible mechanism for the sonodegradation reaction of organic dyes was suggested and discussed.

17.
RSC Adv ; 10(54): 32845-32855, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35516469

RESUMO

In this study, for the first time, a novel magnetically recyclable MIL-101(Cr)/CoFe2O4 nanocomposite was prepared via a facile solvothermal method. The morphology, structural, magnetic and optical properties of the nanocomposite were characterized via field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), UV-visible spectroscopy (UV-visible) and BET surface area analysis. Furthermore, the sonocatalytic activity of the MIL-101(Cr)-based magnetic nanocomposite was explored for the degradation of organic dye pollutants such as Rhodamine B (RhB) and methyl orange (MO) under ultrasound irradiation in the presence of H2O2. Under optimized conditions, the degradation efficiency reached 96% for RhB and 88% for MO. The sonocatalytic activity of MIL-101(Cr)/CoFe2O4 was almost 12 and 4 times higher than that of the raw MIL-101(Cr) and pure CoFe2O4, respectively. The improved sonocatalytic performance of the as-prepared binary nanocomposite can be attributed to the relatively high specific surface area of MIL-101(Cr) and magnetic property of CoFe2O4, as well as the fast generation and separation of charge carriers (electrons and holes) in MIL-101(Cr) and CoFe2O4. In addition, the trapping tests demonstrated that ·OH radicals are the main active species in the dye degradation process. Moreover, the most influencing factors on the sonocatalytic activity such as the H2O2 amount, initial dye concentration and catalyst dosage were investigated. Finally, the nanocomposite was magnetically separated and reused without any observable change in its structure and performance even after four consecutive runs.

18.
RSC Adv ; 10(66): 40005-40018, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-35520823

RESUMO

In this work, an inorganic-organic hybrid nanomaterial, P2Mo18/MIL-101(Cr), based on Wells-Dawson-type (NH4)6P2Mo18O62 polyoxometalate (abbreviated as P2Mo18) and the MIL-101(Cr) metal-organic framework was fabricated by the reaction of (NH4)6P2Mo18O62, Cr(NO3)3·9H2O and terephthalic acid under hydrothermal conditions. The as-prepared recyclable nanohybrid was fully characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) equipped with energy dispersive X-ray microanalysis (EDX), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy and Brunauer-Emmett-Teller (BET) specific surface area studies. All the analyses confirmed the successful insertion of P2Mo18O62 6- heteropolyanion within the cavities of MIL-101(Cr). The encapsulated MIL-101(Cr) showed a considerable decrease in both pore volume and surface area compared with MIL-101(Cr) due to incorporation of the very large Dowson-type polyoxometalate into the three-dimensional porous MIL-101(Cr). The nanohybrid had a specific surface area of 800.42 m2 g-1. The adsorption efficiency of this nanohybrid for removal of methylene blue (MB), rhodamine B (RhB), and methyl orange (MO) from aqueous solutions was evaluated. Surprisingly, the composite not only presented a high adsorption capacity of 312.5 mg g-1 for MB, but also has the ability to rapidly remove 100% MB from a dye solution of 50 mg L-1 within 3 min. These results confirmed that this adsorbent is applicable in a wide pH range of 2-10. The nanohybrid showed rapid and selective adsorption for cationic MB and RhB dyes from MB/MO, MB/RhB, MO/RhB and MB/MO/RhB mixed dye solutions. The equilibrium adsorption data were better fitted by the Langmuir isotherm. Kinetics data indicate that the adsorption of the dye follows a pseudo-second order kinetics model. Also, this material could be effortlessly separated and recycled without any structural modification. Accordingly, it is an efficient adsorbent for removing cationic dyes.

19.
Spectrochim Acta A Mol Biomol Spectrosc ; 240: 118595, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32599480

RESUMO

In the present study, biological synthesis of Ag-ZnO nanocomposites was performed using hydroalcoholic extract of fenugreek leaves. Metal/semiconductor oxide nanocomposites are excellent owing to their optical, electrical, magnetic, and chemical properties that are not detected in single individual constituents. The synthesized Ag-ZnO nanocomposites were investigated through the use of methods such as FTIR, UV vis DRS, SEM-EDX, TEM, XRD, zeta potential analysis, and DLS. The synthesized Ag-ZnO nanocomposites had an average particle size of about 75 nm and a zeta potential of -37.5 mV. The XRD results confirmed that Ag was successfully introduced into the Ag-ZnO nanocomposites via a hydrothermal method. The antimicrobial and antifungal activities of Ag-ZnO nanocomposites were evaluated by agar well diffusion method against three microbial and fungal strains; it was found that the Ag-ZnO nanocomposites were toxic against all the tested microbial and fungal strains. Ag-ZnO nanocomposites was observed to have significant antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals. The Ag-ZnO nanocomposites exhibited excellent photocatalytic activity and stability against the degradation of malachite green under visible light irradiation. The study successfully applied a simple and eco-friendly method for synthesizing efficient multifunctional Ag-ZnO nanocomposites using green synthetic approach.


Assuntos
Nanocompostos , Trigonella , Óxido de Zinco , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Prata
20.
Ultrason Sonochem ; 64: 104727, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31810872

RESUMO

A new organic-inorganic nanohybrid compound, ([Cu{(HOCH2CH2)2NCS2}2]3[PMo12O40] (1)), has been prepared by sonochemical technique using copper(II) dithiocarbamate complex and a Keggin-type polyoxomolybdate in this research. FT-IR, XRD, FE-SEM, TEM, EDX, UV-Vis, TGA, BET, and single crystal XRD analyses were applied to describe the properties of the composition of the nanohybrid. Compound (1) is composed of [PMo12O40]3- building blocks and [Cu{(HOCH2CH2)2NCS2}2]1+ cationic moieties, and electrostatic forces and substantial hydrogen-bonding interactions were applied to pack them; and consequently, a three dimensional supramolecular framework was made based on single-crystal X-ray diffraction patterns. FE-SEM and TEM images approved the morphology of the nanohybrid sample to be extremely penetrable. Very good sonocatalytic performance is shown by this supramolecular nanohybrid in the degradation of Rhodamine B (RhB), which is a cationic organic dye. The results showed complete degradation of cationic RhB (25 mg/L) within 70 min with the rate constant of 0.039min-1 in the presence of nanohybrid (1) and H2O2 (4 mmol/L). Also, sonocatalytic activity of the nanohybrid (1) was higher than H3PMo12O40, showing that the combining Cu(DEDTC)2 complex with H3PMo12O40 could be an excellent choice to improve its sonocatalytic activity. The used nanohybrid (1) can be recycled after easily removing from the reaction media by centrifuging, and there was no considerable loss of catalytic activity and retention of the structure.

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