Micro & Nano Letters
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2020
·Vol. 15
·期 13
·938-942
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IF 0.975
Pengjiao Zhang,Wei Li
Copper oxide/manganese dioxide (CuO/MnO 2 ) nanocomposites were prepared by a facile microwave-assisted synthesis method in an ordinary household microwave oven and used for electrochemical supercapacitor. The nanocomposites were characterised by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Electrochemical results demonstrate that CuO/MnO 2 nanocomposites have better capacitance performance than pure CuO material. The CuO/MnO 2 nanocomposites have a high specific capacitance of 499.0 F/g at a current density of 0.5 A/g in 6 M KOH electrolyte. In addition, an asymmetric supercapacitor with activated carbon as a negative electrode and CuO/MnO 2 nanocomposite as a positive electrode was also successfully prepared. This asymmetric device exhibits a high energy density of 32.07 Wh/kg at a power density of 375.02 W/kg and fairly good cycling stability.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Meiqiang Cai,Yu Zhang,Chunying Dong,Wentao Wu,Qian Wang,Zhijun Song,Yuejing Shi,Liguang Wu,Micong Jin,Dionysios D. Dionysiou,Zongsu Wei
The heterogeneous catalytic process has been under development for aqueous pollutant degradation , yet electron transfer efficiency often limits the effectiveness of catalytic reactions . In this study, a novel composite material, manganese doped iron–carbon (Mn–Fe–C), was tailor designed to promote the catalytic electron transfer. The Mn–Fe–C composite, synthesized via a facile carbothermal reduction method, was characterized and evaluated for its performance to activate persulfate (PS) and degrade Rhodamine Blue (RhB) dye under different pH, catalyst dosages, PS dosages, and pollutant concentrations . Electron spin resonance, along with quenching results by ethanol, tert -butanol, phenol , nitrobenzene and benzoquinone , indicated that surface bounded SO 4 •− was the main contributor for RhB degradation, while the roles of aqueous SO 4 •− and • OH were very minor. Through characterization by XRD, XPS and FTIR analysis, it was determined that the electron transfer during activation of PS was accelerated by the oxygen functional groups on catalyst surface and the promoted redox cycle of Fe 3+ and Fe 2+ by Mn. Finally, the Mn–Fe–C composite catalyst exhibited an excellent reusability and stability with negligible leached Fe and Mn ions in solutions. Results of this study provide a promising design for heterogeneous catalysts that can effectively activate PS to remove organic pollutants from water at circumneutral pH conditions.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2020
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IF 4.65
Jianfei Xiao,Yuan Wang,Tian C. Zhang,Shaojun Yuan
A novel porous carbon derived from glucose and dicyandiamide incorporated with reduced graphene oxide (rGO) was prepared for CO 2 capture and supercapacitors . In this synthesis, one-pot hydrothermal and KOH activation were employed to obtain reducing graphene oxide/N-doped porous carbon (rGO/NPC) composites. Among the rGO/NPC composites derived, the sorbent rGO/NPC-600-2-1 (1 represents the addition amount of graphene oxide is 1% of the total mass of glucose and dicyandiamide, 2 represents the mass ratio of potassium hydroxide to the precursor of carbon composite material is 2 and 600 means activation temperature is 600 °C) had a large surface area of 865.1 m 2 g −1 , a rich nitrogen doping amount of 7.07 wt%, and a high CO 2 capture ability of 5.77 mmol/g at 298 K. Additionally, the as-synthesized rGO/NPC-600-2-1 was used as a supercapacitor electrode, providing a specific capacitance 210.8 F g −1 in 6 M KOH electrolyte under ambient conditions and excellent charge and discharge long cycle stability (circa 100% capacitance retention at a current density of 10 A g −1 after 10000 cycles). Even at a high current density of 20 A g −1 , a capacity of 141.1 F g -1 is still maintained. The results above suggested that the rGO/NPC composites are applicable candidates for both electrochemical energy storage and CO 2 capture.
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CARBOHYDRATE POLYMERS
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2020
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IF 7.182
Xiaoyu Zhang,Huabing Yang,Junping Zheng,Nan Jiang,Guangjun Sun,Xinkun Bao,Aizhen Lin,Hongtao Liu
This study was designed to explore the improvement of chitosan oligosaccharides (COS) on constipation through regulation of gut microbiota. Here, we proved that COS treatment profoundly boosted intestinal motility, restrained inflammatory responses, improved water-electrolyte metabolism and prevented gut barrier damage in constipated mice induced by loperamide . By 16S rDNA gene sequencing, the disbalanced gut microbiota was observed in constipated mice, while COS treatment statistically reversed the abundance changes of several intestinal bacteria at either phylum, family and genus levels, which partly led to the balance in production of intestinal metabolites including bile acids, short-chain fatty acids and tryptophan catabolites. In addition, COS failed to relieve the constipation in mice with intestinal flora depletion, confirming the essentiality of gut microbiota in COS-initiated prevention against constipation. In summary, COS can ameliorate the development of loperamide-induced constipation in mice by remodeling the structure of gut microbial community.
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ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Chongbo Cheng,Pengfei Li,Wenbing Yu,Dekui Shen,Xiaoxiang Jiang,Sai Gu
Lignin containing numerous phenylpropane units is considered to be a renewable and abundant resource for the production of value-added aromatic chemicals. A series of nonprecious metal/bimetallic catalysts were prepared for the catalytic hydrogenolysis of organosolv poplar lignin (OPL) in ethanol/isopropanol solvent in this work. Effects of Ni/C, Cu/C, NiCu/C, and NiW/C catalysts on OPL depolymerization were investigated, where the NiCu/C catalyst was found to be optimal for the conversion of OPL to phenolic monomers at a yield of 63.4 wt % at 270 °C for 4 h without external H2. The synergistic effect of mixed solvent was remarkable during the catalytic hydrogenolysis process, leading to the increased yield of monomer products. The catalytic process of OPL conversion and possible reaction route of ethanol/isopropanol solvent were proposed with regard to the analysis of products and fresh/spent catalysts. The effects of reaction temperature, reaction time, catalyst recyclability, solvent recyclability, and feedstock adaptability were investigated in view of bio-oil and monomer yields. This work provides an economical and sustainable method for the efficient conversion of lignin to high-value chemicals.
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CHEMOSPHERE
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2020
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IF 5.778
Ying Pan,Qiongjie Ding,Baohong Li,Xiaoxiong Wang,Yiwei Liu,Junhao Chen,Fei Ke,Jianqiang Liu
The construction of efficient and superior adsorbed materials for the precise removal of hazardous contaminants from water have gained significant attention by the scientific community. In this work, a facile bimetallic zeolitic-imidazolate framework (Co x Zn y -JUC-160) by using self-adjusted strategy (SAS) was developed to synthesize various N-doped Co-based hierarchical porous carbon composites through sacrificial template route. A series of highly porous magnetic materials with well-dispersed or reduced Co particle size have been fabricated by fine tuning the ratio of Co and Zn in the precursors. For the first time the effect of the Co/Zn ratio on the textural properties and drug adsorption performance of the resultant porous carbon composites have been investigated systematically. Remarkably, the optimal Co@NC-1/4-900 possesses large specific surface area, hierarchical pore structures, and well-distributed Co adsorption sites which facilitates the exposure of active Co center and realizes fast diffusion of amodiaquine (ADQ) molecules with record-high adsorption capacities (890.23 mg g −1 ). The presented synthetic strategy provides deep insights into the development of highly efficient recyclable magnetic adsorbent for the removal of contaminants.
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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2020
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IF 3.209
Dandan Ren,Jie Mei,Jian Bao,Fangdi Wei,Guanhong Xu,Jing Yang,Yong Sun,Qin Hu,Yao Cen
In this work, we reported a novel and convenient profuse color card for naked eye determination of iodide (I − ) in urine using chromogenic substrate 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). I − catalyzed the oxidation of ABTS by peroxyacetic acid causing ABTS to yield cyan product ABTS + with a new absorption peak at 730 nm. The addition of rose-red dye rhodamine B (RhB) changes the overall color of the solution from pink to purple and finally to blue, which makes the solution multicolor and easy to distinguish. A good linear relationship for I − was obtained ranging from 10.0 to 500.0 μg/L with the detection limit of 9.2 μg/L. Importantly, the sensor can semi-quantitatively estimate the concentration of I − in human urine with naked eye through the standard color card and assess the deficiency or excess of iodine in human body. The proposed profuse color card opens up a new colorimetric method for the rapid, simple and reliable determination of I − in clinic, and has promising applications in developing assay kit for the clinical diagnosis of I − in urine.
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SCIENCE OF THE TOTAL ENVIRONMENT
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2020
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IF 6.551
Meiying Yu,Wulin Yang,Xiaole Yuan,Yunfei Li,Nan Li,Weihua He,Yujie Feng,Jia Liu
Membrane filtration electrode based microbial fuel cell provides a promising route to simultaneously recover energy and produce high-quality effluent during water treatment . Enhancing effluent quality and oxygen reduction reaction (ORR) activity of the membrane electrode still remains a major challenge. In this study, filtration types of membrane electrodes with Prussian blue (PB) doping and PVDF-PVC-PEG triblock copolymers were prepared by a simple phase inversion fabrication process. The PB-0.2 membrane electrode with optimal 0.2 wt% of PB obtained the highest current density (12.0 A m −2 ) and the lowest charge transfer resistance (5.0 ± 0.1 Ω). Rotating disk electrode (RDE) results also demonstrated that the PB-0.2 catalyst exhibited the superior ORR activity with the highest number of transferred electrons ( n = 3.90). Furthermore, the MFC with PB-0.2 produced the maximum power density of 1401 ± 17 mW m −2 , which was 186.5% higher than that of the control. Moreover, the filtrated effluent tCOD eff was 20.6 ± 1.2 mg L −1 for the PB-0.2, which was significantly reduced by 63% compared with the control. These results showed that the addition of PB was an effective strategy to enhance the overall oxygen reduction performance and improve effluent quality of microbial fuel cells.
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EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
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2020
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IF 3.616
Xiaoyu Zhang,Junping Zheng,Nan Jiang,Guangjun Sun,Xinkun Bao,Mingwang Kong,Xue Cheng,Aizhen Lin,Hongtao Liu
Lactulose is a common laxative and has been widely applied to clinical treatment for constipation. This study aimed to explore the improving effect of lactulose on constipation through the mediation of gut microbiota and intestinal metabolites. BALB/c mice with constipation induced by loperamide were orally treated with lactulose for four weeks. After the treatment, the constipation-related factors were determined. The effect of lactulose on the composition of gut microbiota was assessed by 16S rDNA gene sequencing. Gas chromatography or liquid chromatography-mass spectrometer (GC/LC-MS) analysis was used for the quantification of intestinal metabolites. The treatment of constipated mice with lactulose accelerated intestinal motility, suppressed inflammatory responses, protected gut barrier, and improved metabolisms of water and salt in the intestinal tract. These therapeutic effects were attributed to the reversed gut microbiota dysfunction, which conferred the benefit to the production of intestinal metabolites including bile acids, short-chain fatty acids, and tryptophan catabolites. Further, the depletion of intestinal flora from loperamide- or (loperamide + lactulose)-treated mice confirmed the significance of gut microbiota in the mediation of constipation. In summary, this study leads us to propose that lactulose may improve constipation through a prebiotic effect on gut microbiota and intestinal metabolites.
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Journal of Environmental Sciences
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2020
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IF 4.302
Kai Liu,Fangbai Li,Qingwen Tian,Chengrong Nie,Yibing Ma,Zhenlong Zhu,Liping Fang,Yuanying Huang,Siwen Liu
Paddy soil and irrigation water are commonly contaminated with hexavalent chromium [Cr(VI)] near urban industrial areas, thereby threatening the safety of agricultural products and human health. In this study, we develop a porous and high specific area bone char (BC) to support nanoscale zero-valent iron (nZVI) and apply it to remediate Cr(VI) pollution in water and paddy soil under anaerobic conditions. The batch experiments reveal that BC/nZVI exhibits a higher removal capacity of 516.7 mg/(g•nZVI) for Cr(VI) than nZVI when normalized to the actual nZVI content, which is 2.8 times that of nZVI; moreover, the highest nZVI utilization is the nZVI loading of 15% (BC/nZVI15). The Cr(VI) removal efficiency of BC/nZVI15 decreases with increasing pH (4 – 10). Coexisting ions (phosphate and carbonate) and humic acid can inhibit the removal of Cr(VI) with BC/nZVI15. Additionally, BC exhibits a strong advantage in promoting Cr(VI) removal by nZVI compared to the widely used biochar and activated carbon. Our results demonstrate that reduction and coprecipitation are the dominant Cr(VI) removal mechanisms. Furthermore, BC/nZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(VI) in paddy soil, as compared to nZVI. These findings provide a new effective material for remediating Cr(VI) pollution from water and soil.
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TRIBOLOGY INTERNATIONAL
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2020
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IF 4.271
Can Wu,Kai Yang,Ying Chen,Jing Ni,Lidan Yao,Xinglin Li
This paper presents a comparative study of the tribological and vibration performance of the synthesized lithium complex grease (LCG) containing Carbon black, Fe 3 O 4 and Al 2 O 3 nanoparticles on rolling bearing . The micromorphology, friction coefficient , worn surface and bearing vibration experiment of four greases were studied. The results show that in presence of nanoparticles friction and wear behaviors are improved compared to LCG without nanoparticles. The best tribological performance is obtained in presence of Al 2 O 3 nanoparticle, which is mainly attributed to its high hardness, cylindrical shape and deposition on the worn surface. Further, the wettability test shows that Al 2 O 3 nanoparticles can effectively promote the flow of base oil on the LCG soap fibers, which results in the most effective bearing vibration suppression.
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Journal of Environmental Chemical Engineering
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2020
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IF 4.3
Yangyi Xiao,Xun Wang,Chenxing Li,Huan Peng,Tuqiao Zhang,Miaomiao Ye
Recently, great efforts have been focused on solar evaporators because they can localize solar heat on the air-water interface resulting in enhanced photothermal conversion efficiency. However, to prevent salt accumulation during evaporation while maintaining high evaporation rates is still a challenge. In this work, a salt-rejecting solar evaporator was fabricated for continuous seawater desalination. The evaporator was composed of a top layer of carbon black (CB) nanoparticles for solar absorbance, an interlayer of superhydrophilic melamine formaldehyde (MF) foam for both seawater and concentrated brine delivery, and an outlayer of expandable polyethylene (EPE) foam for floating and heat insulation. The superhydrophilic MF foam could offer a channel for rapid exchange of the concentrated brine with the solution beneath, thereby preventing salt accumulation in the evaporator. It was demonstrated that the salt-rejecting solar evaporator produced a high water evaporation rate of 1.24 kg·m −2 ·h −1 under 1 kW·m −2 solar irradiance, which was 3.2 times higher than that of the pristine simulated seawater (3.5 wt% NaCl solution). Furthermore, the salt-rejecting evaporator displayed an excellent stability as the water evaporation rate remained constant even after 16-cycles of use within 20 days.
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