Water pollution is one of the main global concerns affecting humans and numerous people die annually because of the diseases inflicted by contaminated water. Due to the toxicity and carcinogenic ...potential of the dyes in effluent, it is necessary to attain an efficient method for wastewater treatment using the highly active and reusable photocatalyst. This study presents a promising green approach for the preparation of heterogeneous catalytic nanoparticles by investigating the synergistic effect of metal ions in spinel structure to enhance their photocatalytic activity. Herein, Mg0.5Zn0.5FeMnO4 magnetic nanoparticles (MNPs) were prepared by a green sol-gel process and thoroughly characterized by X-ray Photoelectron Spectroscopy (XPS), powder X-ray diffraction (XRD), Electrochemical Impedance Spectroscopy (EIS), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), transmission electron microscope (TEM), Brunauer Emmett Teller (BET), Fourier transform infrared spectroscopy (FT-IR), high-solution transmission electron microscopy (HRTEM) images and selected area electron diffraction (SAED), Differential reflectance spectroscopy (DRS), vibrating sample magnetometer (VSM), and elemental mapping. XRD pattern confirmed the spinel structure of Mg0.5Zn0.5FeMnO4 MNPs which displayed good photocatalytic performance for the decolorization of Reactive Blue 21 (RB21) dye under ambient conditions and at natural pH (pH = 6) wherein 96% of dye was degraded in 30 min and total organic carbon removal followed in 30, 60, and 120 min. Mechanistic aspects of the photodegradation were ascertained in presence of scavenger agents and the degradation products were studied by Gas chromatography–mass spectrometry (GC-MS) with identification of smaller ensuing fragmented molecules. Magnetic nanoparticles could be recycled by applying an external magnet, and their efficiency was maintained intact even after five cycles while retaining their structural integrity as attested by XRD, and FESEM analysis after reuse.
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•Green synthesis of Mg0.5Zn0.5FeMnO4 MNPs by Tragacanth gel.•Mg0.5Zn0.5FeMnO4 photocatalyst has a band gap of 1.56 eV and low electron transfer resistance.•96% of RB21 dye was photo degraded after short time 30 min with 48% removal of TOC.•GC-MS results show that the RB21 dye molecules were completely degraded and break down into small molecules.
Patients with multivessel coronary artery disease were randomly assigned to PCI with everolimus-eluting stents or CABG. At 2 years, the composite of death, myocardial infarction, or target-vessel ...revascularization occurred more frequently in the PCI group.
Randomized trials and observational studies have shown that the rates of most adverse clinical outcomes among patients with multivessel coronary artery disease are lower after coronary-artery bypass grafting (CABG) than after percutaneous coronary intervention (PCI).
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Current clinical guidelines thus recommend CABG as the preferred revascularization strategy, particularly in patients with complex coronary lesions and without excessive operative risk.
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However, previous trials may have been limited by their use of first-generation drug-eluting stents. Although these stents reduced the rate of restenosis, their use was associated with a relatively high rate of stent-related thrombotic events.
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Results from the Synergy between . . .
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•Cost effective CO2 adsorbent could be prepared from petroleum coke.•CO2 uptakes have good correlation with narrow micropores (<0.8nm).•The prepared microporous carbon showed ...excellent CO2 adsorption performance.
The capture of CO2 via adsorption is considered an effective technology for decreasing global warming issues; hence, adsorbents for CO2 capture have been actively developed. Taking into account cost-effectiveness and environmental concerns, the development of CO2 adsorbents from waste materials is attracting considerable attention. In this study, petroleum coke (PC), which is the carbon residue remaining after heavy oil upgrading, was used to produce high-value-added porous carbon for CO2 capture. Porous carbon materials were prepared by KOH activation using different weight ratios of KOH/PC (1:1, 2:1, 3:1, and 4:1) and activation temperatures (600, 700, and 800°C). The specific surface area and total pore volume of resulting porous carbon materials increased with KOH amount, reaching up to 2433m2/g and 1.11cm3/g, respectively. The sample prepared under moderate conditions with a KOH/PC weight ratio of 2:1 and activation temperature of 700°C exhibited the highest CO2 adsorption uptake of 3.68mmol/g at 25°C and 1bar. Interestingly, CO2 adsorption uptake was linearly correlated with the volume of micropores less than 0.8nm, indicating that narrow micropore volume is crucial for CO2 adsorption. The prepared porous carbon materials also exhibited good selectivity for CO2 over N2, rapid adsorption, facile regeneration, and stable adsorption–desorption cyclic performance, demonstrating potential as a candidate for CO2 capture.
Abstract This paper reports a simple, biogenic and green approach to obtain narrow band gap and visible light-active TiO 2 nanoparticles. Commercial white TiO 2 ( w -TiO 2 ) was treated in the ...cathode chamber of a Microbial Fuel Cell (MFC), which produced modified light gray TiO 2 ( g -TiO 2 ) nanoparticles. The DRS, PL, XRD, EPR, HR-TEM, and XPS were performed to understand the band gap decline of g -TiO 2 . The optical study revealed a significant decrease in the band gap of the g -TiO 2 (E g = 2.80 eV) compared to the w -TiO 2 (E g = 3.10 eV). The XPS revealed variations in the surface states, composition, Ti 4+ to Ti 3+ ratio, and oxygen vacancies in the g -TiO 2 . The Ti 3+ and oxygen vacancy-induced enhanced visible light photocatalytic activity of g -TiO 2 was confirmed by degrading different model dyes. The enhanced photoelectrochemical response under visible light irradiation further supported the improved performance of the g -TiO 2 owing to a decrease in the electron transfer resistance and an increase in charge transfer rate. During the TiO 2 treatment process, electricity generation in MFC was also observed, which was ~0.3979 V corresponding to a power density of 70.39 mW/m 2 . This study confirms narrow band gap TiO 2 can be easily obtained and used effectively as photocatalysts and photoelectrode material.
We synthesized echinoid-like BiOI microspheres with various doped concentrations of Ag (0.1, 1.0, 5.0, 10.0 mol%) and Ti (1.0, 5.0, 10.0, 30.0, 50.0 mol%) in ethylene glycol and then examined their ...fundamental properties by scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, UV-visible absorption, FT-IR, Raman, photoluminescence and Brunauer–Emmett–Teller (BET) surface area measurements. We also measured the adsorption and photocatalytic dye-degradation performance of the catalysts using methyl orange (MO), Rhodamine B (RhB) and methylene blue (MB). The adsorption performance was found to be in the order of MO < RhB < MB, and to depend somewhat upon the Ag and Ti-loadings. MO was degraded in the order of BiOI < Ag–BiOI < Ti–BiOI under UV and visible light irradiation, while the degradation of RhB was in the order of Ag–BiOI ≈ Ti–BiOI ≪ BiOI, and Ag–BiOI < BiOI < Ti–BiOI, respectively. MB showed poor photodegradation under UV and visible light. Finally, we used an indirect chemical probe method with active species scavengers and photoluminescence spectroscopy to clarify the dye-sensitized photodegradation mechanism. In the mechanism, ˙O 2 − and h + were active species under visible light irradiation. No ˙OH radicals were found by luminescence spectroscopy.
UV–vis absorption changes of MO (10ppm) in the presence of MnFe2O4/g-C3N4/TiO2 (0.5g/L) under simulated solar light irradiation.
•A magnetic nanocomposite was prepared by chemical impregnation ...method.•The absorption of TiO2 was red shifted after modification with MnFe2O4/g-C3N4.•99.27% of MO degradation was achieved using MnFe2O4/g-C3N4/TiO2.•MnFe2O4/g-C3N4/TiO2 could be easily recovered from water using a magnet.
A magnetic nanocomposite composed of manganese ferrite (MnFe2O4), graphitic-carbon nitride (g-C3N4) and titanium dioxide-P25 (TiO2) was synthesized via chemical impregnation method. The as-synthesized nanocomposite (MnFe2O4/g-C3N4/TiO2) was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution TEM (HR-TEM) elemental mapping, energy dispersive X-ray spectroscopy (EDX), UV–visible diffuse reflectance spectroscopy (UV-vis-DRS), photoluminescence (PL), B.E.T. surface area analysis, X-ray photo-electron spectroscopy and vibrating sample magnetometery (VSM) techniques. The band gap of TiO2 was decreased after surface modification with MnFe2O4/g-C3N4. The photocatalytic activity was tested for the degradation of methyl orange (MO) dye as a model pollutant under simulated solar light irradiation. It was found that MnFe2O4/g-C3N4/TiO2 displayed excellent photocatalytic activity than that of g-C3N4, MnFe2O4 and MnFe2O4/g-C3N4. The enhancement in the photocatalytic activity was ascribed to the synergism between TiO2, g-C3N4 and MnFe2O4. VSM results revealed that ferromagnetism was retained in the nanocomposite (MnFe2O4/g-C3N4/TiO2) and it could be easily removed using an external magnet after the photo-reaction. Besides, the durability and stability of magnetic nanocomposite was tested by recycling experiments.
We compared the 10-year graft occlusion rates and long-term clinical outcomes of right gastroepiploic artery (RGEA) composite grafts with those of right internal thoracic artery (RITA) composite ...grafts.
From 2000 to 2008, 548 patients had undergone total arterial revascularization for multivessel coronary artery disease using the RGEA (RGEA group; n = 389) or RITA (RITA group; n = 159) as a second-limb Y-composite graft based on the in situ left ITA. A propensity score-matched analysis was used to match the RGEA group (n = 152) with the RITA group (n = 152). The 10-year angiographic occlusion rates and long-term clinical outcomes were compared. The follow-up data were complete for all 304 patients (100%) with a median follow-up of 143.7 months.
The early clinical outcomes were similar between the matched groups. The overall graft occlusion rate was 9.5% at 10 years in the matched group patients (matched RGEA and RITA groups, 10.3% and 8.4%, respectively; P = .639). The 10-year occlusion rates of the second-limb conduits showed no differences between the matched RGEA and RITA groups (14.1% and 10.2%, respectively; P = .487). No statistically significant differences were found at 15 years postoperatively in the overall survival (52.9% vs 49.4%; P = .470), cardiac mortality-free survival (92.1% vs 90.9%; P = .560), freedom from target vessel revascularization (83.0% vs 91.4%; P = .230), freedom from reintervention (68.8% vs 76.2%; P = .731), or freedom from major adverse cardiac and cerebrovascular events (56.4% vs 64.6%; P = .364) rates between the matched groups.
Total arterial revascularization using RGEA composite grafts showed comparable results to those using RITA composite grafts in terms of the 10-year occlusion rates and long-term clinical outcomes.
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In a randomized trial involving patients who had undergone percutaneous coronary intervention, routine functional testing did not improve clinical outcomes at 2 years.
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