CHROMATOGRAPHIA
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2018
·Vol. 82
·期 3
·695-704
·
IF 1.401
Xue Jiaying,Zhang Dong,Wu Xiangwei,Pan Dandan,Hua Rimao
A new in-tube pretreatment method based on ultrasound assisted dispersive solid–liquid microextraction using self-assembly and solidification of an alkanol-based floating organic droplet was developed for the determination of eight pyrethroid insecticides in chrysanthemum by gas chromatography with electron capture detection. This method fully utilized the restricted access property of a 1-decanol/acetonitrile mixture for effective extraction of the analytes from chrysanthemum under ultrasonication, and the self-assembly and coacervation process of 1-decanol by adding water. The 1-decanol phase aggregated and floated on the surface, solidified in an ice bath, and thus was easily collected. For the first time, extraction, separation and preconcentration were combined in a tube, not requiring stepwise preparation for a solid matrix. The recoveries ranged from 75 to 104% with the relative standard deviations of < 8%. The limits of quantification were in the range of 0.15–1.5 µg kg − 1 up to 52-fold compared with the conventional QuEChERS-based, SPE, and solid–liquid dispersive microextraction methods. The results demonstrated that the proposed method was time-saving, sensitive, and environmentally friendly for pyrethroids analysis in chrysanthemum.
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CELLULOSE
·
2018
·Vol. 25
·期 7
·4133-4144
·
IF 3.809
Geng Aobo,Meng Liang,Han Jingquan,Zhong Qiang,Li Meirun,Han Shuguang,Mei Changtong,Xu Lijie,Tan Lin,Gan Lu
Abstract There is an urgent need to explore alternatives to replace traditional carbonaceous materials because of dwindling oil reserves and increasing atomospheric carbon dioxide. In the present study, the cellulose derived carbon nanofibers (CCNF) were prepared and used to hybridize with bismuth oxybromide to prepare novel photocatalyst composites (CCNF/BiOBr). The structural properties of the prepared composites were then characterized. Afterwards, the photocatalytic performance of the CCNF/BiOBr composites was investigated through degrading rhodamine B (RhB) under continuous visible light irradiation. The results indicated that the pyrolysis process could convert the cellulose to carbon nanofiber with high graphitization degree. The photocatalytic performance of the CCNF/BiOBr composite was better than that of the pure BiOBr, which was ascribed to the introduction of the CCNF into the composite system. The present work provides a promising way to design new photocatalyst composites with desirable carbon alternatives from biomass materials for effective treatment of organic contaminants in water media. Graphical Abstract
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WATER AIR AND SOIL POLLUTION
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2018
·Vol. 229
·期 6
·1-11
·
IF 1.769
Wang Jian,Yan Yanan,Tian Lili,Wang Qinmei,Zhang Yan,Cao Weiqin,Yang Chun
Reactive Red 141 (RR 141) was efficiently adsorbed and enriched from an aqueous solution by oppositely charged cryogels. The cryogels were prepared with acryl amide (AAm) and dimethyl diallyl ammonium chloride (DDAC) as the monomers, along with N,N′-methylene-bis acrylamide (MBA) as the cross-linker. In the presence of DDAC, the prepared macroporous cryogels hold a strong affinity to the reactive dye. The elasticity and mechanical properties of the cryogels were improved when the mass ratio of the monomer and the cross-linker was 2:1. A maximum adsorption capacity was achieved with 21 wt% of DDAC in reactants. The impacts of conditions of non-aqueous electrolysis such as solvent types, electrolytic voltages, and electrolyte concentrations were investigated. When subjected to non-aqueous electrolysis in organic media of N-methyl pyrrolidone (NMP), propylene carbonate (PC), and ethylene carbonate (EC), the cryogel-adsorbed dye underwent a quick and efficient degradation. Higher Faradaic efficiencies were obtained compared with that from the same operations in aqueous media. The specific degradation rate of RR 141 in a non-aqueous electrolysis is substantially larger than that reported. In addition, both the cryogel and the organic solvents can be repeatedly used, making it a sustainable method to deal with related pollution problems of reactive dyes.
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Nano Research
·
2018
·Vol. 11
·期 6
·3396-3410
·
IF 7.994
Wu Dongyan,Wang Huaisong,Hou Xiaoshuang,Chen Huan,Ma Yu,Hou Yanglong,Hong Jin,Ding Ya
Studies on the influence of one critical parameter (e.g., size), targeting a specific disease, while keeping other factors unchanged, are important for improving understanding and application of the molecular design of biomedical nanomaterials. In this study, we used doxorubicin (Dox)-conjugated gold nanoparticles (GNPs) to investigate the effects of the size of the gold core (10, 20, or 60 nm) on the performance of their conjugates. We found that all three conjugates differed slightly in their physicochemical properties, facilitating a direct and accurate assessment of the size effects of GNP-Dox conjugates on their in vitro and in vivo performance. The cytological properties (the cell penetration rate and efficiency, as well as the cytotoxicity) and antitumor performance (the intratumoral penetration, treatment efficacy, and biodistribution) were highly correlated to the size of the inorganic core. Among all test groups, although the conjugate with a 60-nm gold core had the highest drug loading and release efficiency, the conjugate with a 10-nm gold core displayed the best antitumor efficacy toward the liver cancer models. This was because it showed the deepest tumor permeability and the highest tumor cell-killing ability of Dox transported by the relatively small GNPs. This study provides important evidence for better understanding the effect of size on in vitro and in vivo properties of potential therapeutic nanosystems and their structure design.
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JOURNAL OF ELECTRONIC MATERIALS
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2018
·Vol. 47
·期 7
·4085-4089
·
IF 1.566
Shao Li-Huan,Shen Si-Yun,Zheng Hui,Zheng Peng,Wu Qiong,Zheng Liang
Compact hexagonal barium ferrite (BaFe 12 O 19 , BaM) ceramics with excellent magnetic properties have been prepared from powder with the optimal grain size. The dependence of the microstructure and magnetic properties of the ceramics on powder grain size was studied in detail. Single-phase hexagonal barium ferrite powder with grain size of 177 nm, 256 nm, 327 nm, and 454 nm was obtained by calcination under different conditions. Scanning electron microscopy revealed that 327-nm powder was beneficial for obtaining homogeneous grain size and compact ceramic. In addition, magnetic hysteresis loops and complex permeability spectra demonstrated that the highest saturation magnetization (67.2 emu/g) and real part of the permeability (1.11) at 1 GHz were also obtained using powder with grain size of 327 nm. This relationship between the powder grain size and the properties of the resulting BaM ceramic could be significant for development of microwave devices.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 21
·20756-20768
·
IF 2.8
Wang Zhiwei,Bu Yibin,Zhao Yonghe,Zhang Zuotai,Liu Lifen,Zhou Hao
Although tellurite is highly toxic to organisms, elemental tellurium nanomaterials (TeNMs) have many uses. The microbe-mediated reduction of tellurite to Te(0) has been shown to be a green and cost-effective approach for turning waste into wealth. However, it is difficult to tune the morphology of biogenic nanomaterials. In this study, a series of experiments was conducted to investigate the factors influencing tellurite reduction by the tellurite-reducing bacterium Lysinibacillus sp. ZYM-1, including pH, tellurite concentration, temperature, and heavy metal ions. The optimal removal efficiency of tellurite was respectively achieved at pH 8, 0.5 mM tellurite, and 40 °C. All of the tested metal ions retarded the reduction of tellurite, especially Cd 2+ and Co 2+ , which completely inhibited its reduction. Further characterization of the biogenic TeNMs indicated that their morphology could be tuned by the tellurite concentration, pH, temperature, and organic solvents used. Regular Te nanosheets were produced using 5 mM tellurite. The TeNMs were primarily synthesized in the cell membrane. Hexagonal Te nanoplates, nanorods, nanoflowers, and nanobranches were synthesized when combining membrane fractions with tellurite and NADH. The diverse morphologies are assumed to be induced by the synergy between the reduction kinetics and the protein structure. Therefore, this study confirmed that the bacterium can tune the morphology of TeNMs, broadening the potential application of biogenic TeNMs.
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PubMed
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Nano Research
·
2018
·Vol. 11
·期 5
·2450-2459
·
IF 7.994
Zhang Bing,Zhao Tian-Jian,Feng Wei-Jie,Liu Yong-Xing,Wang Hong-Hui,Su Hui,Lv Li-Bing,Li Xin-Hao,Chen Jie-Sheng
The greenhouse effect and global warming are serious problems because the increasing global demand for fossil fuels has led to a rapid rise in greenhouse gas exhaust emissions in the atmosphere and disruptive changes in climate. As a major contributor, CO 2 has attracted much attention from scientists, who have attempted to convert it into useful products by electrochemical or photoelectrochemical reduction methods. Facile design of efficient but inexpensive and abundant catalysts to convert CO 2 into fuels or valuable chemical products is essential for materials chemistry and catalysis in addressing global climate change as well as the energy crisis. Herein, we show that two-dimensional fewlayer graphitic carbon nitride (g-C 3 N 4 ) can function as an efficient metal-free electrocatalyst for selective reduction of CO 2 to CO at low overpotentials with a high Faradaic efficiency of ~ 80%. The polarized surface of ultrathin g-C 3 N 4 layers (thickness: ~ 1 nm), with a more reductive conduction band, yields excellent electrochemical activity for CO 2 reduction.
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CELLULOSE
·
2018
·Vol. 25
·期 7
·4167-4177
·
IF 3.809
Dang Baokang,Chen Yipeng,Yang Ning,Jin Chunde,Sun Qingfeng
Abstract Functionalized lignocellulose (LC) wrapped with aluminosilicate was fabricated via a facial mechanical grinding assisted hot-pressing method, which used for flame retardant composite. The aluminosilicate particles with an average size of 3 μm were distributed on the lignocellulose surface by hydrogen bonds and viscous polyacrylamide (PAM). The as-prepared aluminosilicate-PAM/lignocellulose (A-PAM/LC) composite exhibited the excellent flame-retardancy and mechanical properties. The thermal decomposition of A-PAM/LC composite delayed by 31 °C as the aluminosilicate was loaded. The heat release rate (HRR) and total heat release (THR) of A-PAM/LC composite was reduced by 20.6 and 41.1%, respectively. Meanwhile, the A-PAM/LC composite showed the maximum bending strength of 34.23 ± 1.52 MPa and increased by 67.3% compared to the PAM/LC composite. Graphical Abstract Aluminosilicate wrapped PAM/lignocellulose composite showed excellent flame-retardant and mechanical properties.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 13
·11336-11344
·
IF 2.324
Qiu Zhilei,Tian Xuemin,Li Yan,Zeng Yan,Fan Chao,Wang Mengjun,Hua Zhongqiu
In this paper, WO 3 nanosheets were prepared by an acidification method and Ru catalyst was loaded on the surface of nanosheets through a conventional impregnation process. NH 3 gas sensors based on the neat and Ru-loaded WO 3 nanosheets were fabricated by the scree-printing technique and their sensing properties to NH 3 were investigated. The morphologies and surface structures of neat and Ru-loaded WO 3 nanosheets were analyzed. It is revealed that WO 3 nanosheets have an irregular flake shape and Ru catalyst is found on the surface of nanosheets with an oxided state. It is also found that the sensor response of WO 3 is greatly improved by the loading of Ru. Based on the power-law response of oxygen and TPR results, the sensitization mechanism of Ru is explained. It is proposed that the introduction of Ru promotes the catalytic activity of WO 3 and in turn modulates the reaction route of NH 3 with oxygen adsorbates on the surface, which inhibit the generation of nitrogen oxides and consequently reduces the competitive adsorption with oxygen during the sensor responses.
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MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 7
·1-9
·
IF 5.705
Da Qiang,Gu Yuanyuan,Peng Xiafeng,Zhang Liying,Du Shuhu
A colorimetric and visual method is described for the determination of mercury(II) ion. A gel consisting of agar-stabilized silver-coated gold nanoparticles (Au@Ag NPs) was prepared. The reaction with dithiothreitol (DTT) via thiol-Ag chemistry results in an orange to purple color change of the gel. However, in the presence of Hg(II), the reaction of DTT with the silver shells is suppressed due to the strong thiophilicity of Hg(II). The color of the gel changes from purple to red to orange in the presence of increasing concentrations of Hg(II). The Au@Ag NPs therefore are a viable optical probe for Hg(II) which can be detected in concentration as low as 78 nM via dual-wavelength ratiometric absorbance (A 390 /A 520 ), and at 1 μM levels with bare eyes. The use of agar as a support is mandatory to prevent the aggregation of the NPs and also improves selectivity. The method was applied to the analysis of spiked samples, and recoveries ranged between 96.3 and 104%. The assay is easy, inexpensive, and in our perception represents an attractive tool for on-site visual detection of Hg(II).
Schematic of the assay. With increasing concentrations of Hg(II), the oxidative etching of silver shells caused by dithiothreitol (DTT) is gradually inhibited, and the color of agar-stabilized Au@Ag NP gel varies from purple to red, and finally to orange. This can be used for visual detection of Hg(II).
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 26
·26069-26078
·
IF 2.8
Peng Na,Wang Kaifeng,Lin Siwu,Wu Libin
Photolysis of the widely used beta-blocker propranolol (PRO) was investigated in the presence of fulvic acid (FA) and inorganic ions under simulated solar irradiation. PRO undergoes direct photolysis proceeding mainly via degradation of the triplet excited state, 3 PRO*. FA and inorganic ions inhibited photolysis of PRO in the order of FA > Fe 3+ > Cl − > Ca 2+ > Mg 2+ > NO 3 − > K + . An antagonistic effect between FA and inorganic ions toward the suppression of PRO photolysis was exhibited. The binding behaviors of PRO, FA, and inorganic ions were examined through fluorescence quenching experiments, which showed that inorganic ions affected the binding between FA and PRO through competing for the binding sites of FA or PRO. The correlation analysis demonstrated a positive correlation between the binding constant ( K OC ) of FA-PRO and the inhibition rate of FA on PRO photolysis. The observed rate constants of photolysis ( k obs ) have opposite correlations with the concentration of singlet oxygen ( 1 O 2 ). These findings strongly suggest that inorganic ions decrease the inhibition effect of FA on PRO photolysis via restraining the complexation of FA-PRO and production of 1 O 2 .
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高影响因子
Nature Energy
·
2018
·Vol. 3
·期 8
·674-681
·
IF 46.859
Zeng Ziqi,Murugesan Vijayakumar,Han Kee Sung,Jiang Xiaoyu,Cao Yuliang,Xiao Lifen,Ai Xinping,Yang Hanxi,Zhang Ji-Guang,Sushko Maria L.,Liu Jun
Non-flammable electrolytes could intrinsically eliminate fire hazards and improve battery safety, but their compatibility with electrode materials, especially graphite anodes, remains an obstacle owing to the strong catalytic activity of the anode surfaces. Here, we report an approach that improves the stability of non-flammable phosphate electrolytes by adjusting the molar ratio of Li salt to solvent. At a high Li salt-to-solvent molar ratio (~1:2), the phosphate solvent molecules are mostly coordinated with the Li + cations, and the undesired reactivity of the solvent molecules toward the graphite anode can be effectively suppressed. High cycling Coulombic efficiency (99.7%), good cycle life and safe operation of commercial 18650 Li-ion cells with these electrolytes are demonstrated. In addition, these non-flammable electrolytes show reduced reactivity toward Li-metal electrodes. Non-dendritic Li-metal plating and stripping in Li–Cu half-cells are demonstrated with high Coulombic efficiency (>99%) and good stability.
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