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•The degradation efficiency of TC over the 0.3-p-Ag2S/n-BiVO4 can be achieved 90.2%.•Ten intermediate products for TC degradation were verified by the GC-MS.•The enhancing ...photocatalysis mechanism was attributed to the facilitated charge transfer.
Three-dimensional microsphere p-Ag2S/n-BiVO4 p-n heterojunction photocatalyst was successfully fabricated via depositing p-type Ag2S on n-type BiVO4, which showed excellent photocatalytic performance, compared with BiVO4 and Ag2S, for the photocatalytic degradation of tetracycline under visible light irradiation. The enhancing photocatalytic performance can be attributed to the facilitated charge transfer, and the increased lifetime of the charge carriers confirmed by the results of time-resolved fluorescence spectra and photoelectrochemical measures. Moreover, 10 photocatalytic degradation intermediates and products were also identified by the gas chromatography-mass spectrometer. Finally, the photocatalytic enhancement mechanism over p-Ag2S/n-BiVO4 was discussed. The strategy to form three-dimensional microspheres p-n heterojunction photocatalyst may open a new opportunity to design highly efficient photocatalyst for environmental treatment to control pollution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
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•A strong metal-edge interaction (SMEI) was formed between Pt NPs and edges of h-BN.•The SMEI was well characterized and the charge transfer was clarified.•The SMEI induced a promoted ...aerobic oxidative desulfurization activity.•The catalyst showed excellent stability because of the SMSI.
Platinum nanoparticles (Pt NPs) have long been regarded as efficient catalysts for numerous catalytic process, including catalytic oxidation, hydrogenation, etc. For Pt catalysis, tuning the electronic structure for a boosted catalytic performance and exploring a proper strategy for stabilization of the nanoparticles are the two central issues. In this work, we constructed strong metal-edge interactions (SMEI) between well-dispersed Pt NPs and hexagonal boron nitride (h-BN) support. The charge transfer between h-BN and Pt NPs was carefully studied, and it was found that the charge transfers from B atoms in h-BN to Pt NPs and from Pt NPs to N atoms in h-BN. The SMEI makes the Pt NPs positively charged for a boosted aerobic catalytic desulfurization activity with sulfur removals of 98.3%, 96.5%, 93.7% and 85.9% to dibenzothiophene, 4, 6-dimethyldibenzothiophene, 4-methylbenzothiophene, and benzothiophene, respectively. Additionally, the aerobic oxidative desulfurization system showed an excellent resistance performance to olefins and aromatic hydrocarbons. The SMEI also gives rise to an excellent stabilization of the Pt NPs without agglomeration after the reaction. Moreover, the catalyst can be recycled 5 times without a significant decrease in catalytic activity. Additionally, both the geometric structure and the SMEI were well investigated to illuminate the structure-activity relationship.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
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•Lifetime of the charge carriers was obtained by time-resolved fluorescence spectra.•Ag/p-Ag2O/n-BiVO4 plasmonic photocatalyst exhibits excellent photocatalytic activity.•The band ...structure was revealed via the valence band XPS and CASTEP code.•The enhancing photocatalysis mechanism was discussed.
Herein, we demonstrate the successful construction of a novel flowerlike Ag/p-Ag2O/n-BiVO4 plasmonic photocatalyst for the photocatalytic oxidation of BPA and reduction of chromium(VI) simultaneously under visible light irradiation. Among these samples, 2mM-Ag/p-Ag2O/n-BiVO4 exhibits the highest photocatalytic performances. The photocatalytic reduction and oxidation efficiency can achieve 69.8 and 91.9%, respectively, after 100 min visible-light irradiation. The enhancement mechanism for the plasmonic photocatalyst is explored, which can be attributed to the enhanced absorbance in the visible light region, and the facilitated charge transfer and the suppressed recombination of electron-hole pairs in the Ag/p-Ag2O/n-BiVO4. The results of the electrochemical impedance spectroscopy, the fluorescence emission spectra and the time-resolved fluorescence emission decay spectra indicate the enhanced charge separation in the Ag/p-Ag2O/n-BiVO4 plasmonic photocatalyst. In addition, the free radical scavenging test shows that h+ and OH radicals play crucial roles in the photocatalytic oxidation reaction. The photogenerated electrons in the photocatalytic reduction process, are confirmed by the DMPO spin-trapping technology. Moreover, the band structures of various photocatalysts are revealed via the valence band XPS spectra and the Fermi level obtained by CASTEP code.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
A heterogeneous catalyst system was synthesized by immobilizing phosphotungstic acid on ionic liquid-modified mesoporous silica SBA-15 and applied in oxidative desulfurization. Structure and ...properties of catalyst were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the contact angle. The results demonstrated that the synthesized catalyst possessed ordered mesopore structure and high special surface area. Due to the introduction of imidazole-based ionic liquid, the catalyst exhibited good wettability for model oil, which had significant contribution to desulfurization activity. Both DBT and 4,6-DMDBT could be removed completely at mild conditions (60 °C, 40 min). The removal of BT also can reach 81.3% within 60 min. Furthermore, the catalyst was recovered and reused in four reaction runs with a slight decrease in activity.
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IJS, KILJ, NUK, PNG, UL, UM
Oxidative desulfurization (ODS) has been proved to be an efficient strategy for the production of clean fuel oil. Numerous metal-based materials have been employed as excellent ODS catalysts, but ...being hindered by their high-cost and potential secondary pollution. In this work, we employed graphene analogous hexagonal boron nitride (h-BN) as a metal-free catalyst for ODS with hydrogen peroxide (H2O2) as the oxidant. The h-BN catalyst was characterized and proved to be a few-layered structure with relatively high specific surface areas. The h-BN catalyst showed a 99.4% of sulfur removal in fuel oil under the optimized reaction conditions. Besides, the h-BN can be recycled for 8 times without significant decrease in the catalytic performance. Detailed mechanism analysis found that it is the boron radicals in h-BN activated H2O2 to generate ·OH species, which can readily oxidize sulfides to corresponding sulfones for separation. This work would provide another choice in choosing metal-free catalysts for ODS.
Hexagonal boron nitride was employed as a metal-free catalyst in oxidative desulfurization of fuel with H2O2 as the oxidant. Due to the boron radicals, the H2O2 is readily activated, achieving ultra-deep desulfurization. Display omitted
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
We have investigated both the GTA (glycerol to aromatics) reaction routes and aromatic products distributions over a series of dealuminated HZSM-5 catalysts to produce BTX aromatics-enriched oil from ...biomass derived glycerol. As the acid site density in dealuminated HZSM-5 catalysts decreased, the induction period of GTA process became longer. The GTA reaction route was almost unaffected over HNO3 treated HZSM-5 catalyst. However, the liquid route of GTA procedure was enhanced while the gas route was restrained over steaming dealuminated HZSM-5 catalyst. The mild HNO3 treatment could preferentially remove the non-shape selective acid sites from HZSM-5 extra-framework, promoting BTX aromatics formation. In contrast, dealumination by harsh steaming transformed HZSM-5 framework tetrahedral Al species (FAL) into EFAl species, leading to a decrease in the BTX aromatics yields together with an increment in the yields of trimethylbenzene and durene. Furthermore, the steaming treatment created an intramesopore structure, which improved the diffusion property in the GTA process, resulting in an improved life span of dealuminated HZSM-5 catalyst. The successive steaming and HNO3 leaching over HZSM-5 could not only extract the EFAl species formed in 3 h 500 °C/HZSM-5 sample, reopening the EFAl-blocked micropores, but also create intracrystalline mesopores, as a consequence, non-shape selective catalytic side reactions and coking were restrained simultaneously during the GTA process, so the resulting catalyst produced BTX aromatics-enriched oil from biomass derived glycerol and exhibited significantly prolonged catalyst lifetime.
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•The induction period becomes longer with increasing the severity of dealumination.•The GTA reaction route was almost unaffected over HNO3 treated HZSM-5 catalyst.•The GTA reaction route was somewhat changed over steaming dealuminated HZSM-5.•Successive steaming and acid leaching HZSM-5 produced BTX aromatics-enriched oil.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Abstract
Missing older adults (MOAs) are older adults whose whereabouts cannot be established at present or at any time previously. The MOAs represent a notable intersection of old age and ...missingness, given the accelerating population aging and sizable missing persons in many societies. However, the prevalence and patterns of mental and cognitive conditions of MOAs have received little attention. This study aimed to address this gap. This study collected data from the Toutiao Alert, a large missing-person appeal platform in China. The analytical sample included 32885 MOAs (mean age, 73.6 years; female, 40.2%) who were reported missing on the platform between 2017 and 2021. The mental and cognitive impairments and other measures were extracted from the reported information. The results show that the overall levels of mental and cognitive impairments among MOAs were 10.6 and 41.5%, respectively. Moreover, these levels varied by gender, age, and spatiotemporal factors such as the region and year of missingness. Women exhibited higher levels of mental and cognitive impairments. Age was associated with lower levels of mental impairments but higher levels of cognitive impairments. Across regions, MOAs from Northeast China had lower levels of mental and cognitive impairments. From 2017 to 2021, the mental or cognitive impairment levels initially decreased, but then increased until the most recent year. The prevalence and patterns of mental and cognitive impairments revealed in this study contributed to our understanding of the health and well-being of MOAs as one of the distinct groups within the expanding elderly population. Future healthcare policies and services targeting MOAs may benefit from these findings.
A series of W-containing mesoporous silicas were designed, prepared and evaluated as the catalysts of oxidative desulfurization. Display omitted
•W-mesoporous silicas were synthesized by functional ...IL (n-C8H17)3NCH32W2O11.•The functional IL acted as template and W precursors during the synthesis process.•W species were highly dispersed into the mesoporous silica.•The catalysts showed good catalytic performance and reusability.
A series of W-containing mesoporous silicas with different calcination temperatures were in situ synthesized by using (n-C8H17)3NCH32W2O11 not merely as a novel template but also the W precursors. The catalysts were characterized by N2 adsorption–desorption, XRD, XPS, HRTEM, EDS, ICP, FTIR, and UV–vis DRS analysis. The N2 adsorption–desorption and HRTEM results indicated that these catalysts possessed mesoporous structure with relatively uniform pores and large internal surface areas. The XRD, ICP and HRTEM results indicated that the W species were highly dispersed on the surface and into the mesoporous silicas matrix. The catalysts also showed excellent catalytic performance on the removal of refractory bulky molecule sulfur compounds from the model oil with H2O2. Based on the removal of DBT in the model oil, the optimal calcination temperature of the catalysts is 450°C. The catalytic activity of different sulfur-containing substrates was also investigated. After 8-times recycling, the sulfur removal could still reach 99.2% without any significant decrease.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
The adsorption-enhancing TiO2-SBA-15 photocatalyst has been synthesized by an in situ etching displacement method, which possesses unique regular hexagonal pores and large specific surface area. The ...as-prepared TiO2-SBA-15 can effectively adsorb and increase the concentration of pollutants in the photocatalyst and collision likelihood with the photogenerated radicals, thus improving the efficiency of photocatalytic organic degradation. The structure and morphology have been characterized by N2 adsorption isotherms, X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and scanning electron microscopy (SEM). These characterizations confirm that TiF4 alcohol solution prefers to react with the internal surface of SBA-15 because of the Siphon effect. Fourier transform infrared (FTIR) spectra demonstrate that a Ti-O-Si bond formed after the reaction of TiF4 with SBA-15, which reveals a wonderful combination of TiO2 and SiO2 even at low temperatures. Through this function, the nanocomposite TiO2-SBA-15 could obviously improve the efficiency of photocatalytical removal of toluene in the gas phase.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
, or group A
, is a pathogen responsible for a wide range of clinical manifestations, from mild skin and soft tissue infections and pharyngitis to severe diseases. Its epidemiological characteristics ...should be comprehensively under surveillance for regulating the national prevention and treatment practice. Herein, a total of 140
, including 38 invasive and 102 noninvasive isolates, were collected from infected patients in 10 tertiary general hospitals from 7 cities/provinces in China during the years 2009-2016. All strains were characterized by classical and molecular techniques for its
types/subtypes, virulent factors and antibiotic resistance profiling. Of 140 isolates, 15 distinct
types and 31 subtypes were detected, dominated by
12 (60 isolates, 42.9%),
1(43, 30.7%), and
89 (10, 7.1%), and 8 new
variant subtypes were identified. All strains, invasive or not, harbored the superantigenic genes,
and
. The other virulence genes,
, and
accounted for 96.4, 91.4, and 87.1% of collected isolates, respectively. Further multilocus sequence typing (MLST) placed all strains into 22 individual sequence types (STs), including 4 newly-identified STs (11, 7.9%). All isolates were phenotypically susceptible to penicillin, ampicillin, cefotaxime, and vancomycin, whereas 131(93.5%), 132(94.2%), and 121(86.4%) were resistant to erythromycin, clindamycin, and tetracycline, respectively. Our study highlights high genotypic diversity and high prevalence of macrolide resistance of
among clinical isolates circulating in China.
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