JOURNAL OF CHROMATOGRAPHY A
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2019
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IF 3.858
Ning Zhang,Lishen Su,Suning Man,Xiaoyun Lei,Ting Huang,Chunling Zhu,Lan Zhang,Xiaoping Wu
A direct immersion solid-phase microextraction (DI-SPME) approach for gas chromatography-mass spectrometry (GC–MS) based on hybrid fiber coating of ionic liquid and polyhedral oligomeric silsesquioxane (POSS) is presented. To fabricate the task-specific coating for the enrichment of polycyclic aromatic hydrocarbons (PAHs), 1-butyl-3-vinylimidazolium bis[(trifluoromethyl)sulfonyl]imide (IL) and POSS were rapidly photoinitiated copolymerized within 5 min on a stainless steel fiber. The high efficient extraction of target analytes can be attributed to a combined result of multiple interactions including the strong C F⋯H C pseudohydrogen bonding, π-π stacking, hydrophobic force, and molecular sieve effect. A wide linear range (0.04–400 ng L −1 ) with low detection limits in the range of 0.004 and 0.5 ng L −1 were obtained for PAHs by GC–MS. The applicability of this coupling method was successfully demonstrated by the analysis of trace PAHs in real river water and soil samples, with satisfied recoveries (84.2–108.6%) and relative standard deviations (<8.1%). Compared to the other commercial fiber-based SPME methods, the IL/POSS hybrid coating-based SPME is much cheaper, thermally stable and capable of eliminating possible deleterious effects as well.
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Nature Communications
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2019
·Vol. 10
·期 1
·1-8
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IF 11.878
Wang Mengfan,Liu Sisi,Qian Tao,Liu Jie,Zhou Jinqiu,Ji Haoqing,Xiong Jie,Zhong Jun,Yan Chenglin
Ambient electrochemical N 2 reduction is emerging as a highly promising alternative to the Haber–Bosch process but is typically hampered by a high reaction barrier and competing hydrogen evolution, leading to an extremely low Faradaic efficiency. Here, we demonstrate that under ambient conditions, a single-atom catalyst, iron on nitrogen-doped carbon, could positively shift the ammonia synthesis process to an onset potential of 0.193 V, enabling a dramatically enhanced Faradaic efficiency of 56.55%. The only doublet coupling representing 15 NH 4 + in an isotopic labeling experiment confirms reliable NH 3 production data. Molecular dynamics simulations suggest efficient N 2 access to the single-atom iron with only a small energy barrier, which benefits preferential N 2 adsorption instead of H adsorption via a strong exothermic process, as further confirmed by first-principle calculations. The released energy helps promote the following process and the reaction bottleneck, which is widely considered to be the first hydrogenation step, is successfully overcome.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Chen-Xuan Li,Chang-Bin Chen,Yun-Jie Wang,Xian-Zhong Fu,Shuo Cui,Jia-Yuan Lu,Jie Li,Hou-Qi Liu,Wen-Wei Li,Tai-Chu Lau
The formation of halogenated disinfection byproducts (DBPs) during organic pollutants degradation in advanced oxidation processes (AOPs) has raised growing concerns globally. However, the detailed roles of chlorine ions (Cl − ) in pollutant degradation by peroxymonosulfate (PMS) alone remain controversial so far. Here, we shed light on the PMS-Cl − -phenol interactions and revealed a previously overlooked pH-dependent phenol transformation pathway. At acidic pH, Cl − significantly accelerated the phenol removal. The Cl − -PMS reaction resulted in abundant reactive chlorine species, which attacked phenol to form 4-chlorophenol and 2, 4-dichlorophenol as the main transformation products. In contrast, the impact of Cl − became negligible at alkaline pH. Raising the pH severely suppressed the phenol chlorination and significantly stimulated generation of singlet oxygen ( 1 O 2 ) for degradation of phenol and the minor formed chlorophenols. The 1 O 2 was resulted from a combined effect of PMS self-decomposition and PMS-benzoquinone interaction at alkaline pH. Our results imply a previously-underestimated impact of Cl − on phenolic compounds degradation in PMS-based AOPs and underscore a potential risk of chlorinated DBPs formation under environmental conditions.
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Canadian Journal of Chemistry
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2019
·Vol. 97
·期 4
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IF 1.252
Jun Wang,Junyi Xie,Libo Wang,Yan Jiang,Na Zhang
A salen nickel complex has been prepared in good yield with ethylenediamine, salicylaldehyde, and NiCl2·6H2O as raw materials. The structure of the complex was characterized by FTIR, 1H NMR, UV, and ESI-MS. Upon activation with methylaluminoxane (MAO), the precatalyst showed high activity for ethylene oligomerization. To reduce the simultaneous production of insoluble polymers during the nickel-catalyzed ethylene oligomerization, a series of phenolic compounds were introduced as modifiers for the production of linear α-olefins. The researched result showed that the phenolic compounds have a significant impact on the selectivity of oligomers and the concentration of polymers. With the increase of phenolic compounds, the content of polymers decreased and the distribution of oligomers gradually shifted toward lighter olefins. The sterically hindered 4-tert-butyphenol proved to be an especially efficient polymer-retarding modifier among the studied phenolic compounds in this work. Furthermore, the retarding effect of phenolic compounds toward insoluble polymers may be mainly related to their interaction with MAO, giving rise to larger MAO aggregates.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Mei Xiang,Dongfang Wu
A detailed investigation was carried out to develop novel pore- and morphology-controllable ETS-10 zeolite. The XRD , N 2 adsorption/desorption, SEM, TEM and 29 Si NMR MAS results proved that a series of hierarchical ETS-10 zeolites was successfully synthesized and more importantly, their morphologies and pore sizes can be freely confined in the desired range under the mesoporogen, morphology- and structure-directing actions of different additives. What's more, the close relationship between various additives and raw materials especially titanium source was discussed, which played an active part in morphology change and hierarchical pores formation. This can be ascribed to the special reducibility of inorganic Ti source, system liquidity and pH, and the enhanced inorganic species dissolution. Finally, the synthesized hierarchical ETS-10 materials were used as heterogeneous catalysts for different biomass-derivatives hydrogenation. Remarkably catalytic performance can be attributed to the unique TiO 6 octahedra carrying two negative charges that strengthens the interaction with active metal species, and thus improves their dispersion. Moreover, the inherent strong Lewis basicity and moderate Lewis acidity favor the oriented conversion of reactants. The controllably hierarchical structure and morphology benefit exposure of more highly dispersed active sites and prolong the catalyst life circle. Especially, an analogous molecular-recognition pattern was found by using sodium lignosulphonate, which is identified as the leading role in noticeably enhancing the catalytic activity and selectivity of the correspondingly ETS-10-based catalyst.
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MICROCHEMICAL JOURNAL
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2019
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IF 3.206
Yinhui Yi,Lirong Liu,Wei Zeng,Baohe Lv,Gangbing Zhu
Being awfully harmful to the environment and human health, the sensitive and selective determination of p-dihydroxybenzene (p-DHB) in environmental water is of great significance. However, the similar structures and properties of p-DHB with catechol (CC; one p-DHB isomer) make the selective and reliable determination of p-DHB from CC in environmental waters being still a formidable challenge. In this manuscript, by preparing CC stabilized silicon quantum dots (C-SiQDs) via a simple hydrothermal process and using C-SiQDs simultaneously as a catalyst and fluorescence indicator, a novel nanosensing platform was successfully developed to selectively and sensitively detect p-DHB with double signals: fluorescence and colorimetric. For detecting p-DHB, C-SiQDs could catalyze the oxidation of p-DHB to form benzoquinone (BQ), an intermediate, which lead to the color change from pale yellow to dark brown and the efficient quenching the fluorescence of C-SiQDs. While for CC in samples, it could not contact C-SiQDs surface due to the great steric hindrance effect from CC on quantum dots surface, thus restricting the oxidation of CC and production of BQ, and leading that the obtained C-SiQDs have no response towards CC. Meanwhile, the developed nanosensor could also avoid various other possible interferences. Under optimized conditions, wide linear ranges (from 0.01 μM to 50.0 μM) and low detection limits (4.0 nM) were obtained for p-DHB. The simple and reliable C-SiQDs-based double signals proposal demonstrated to be potentially applicable for the highly selective and sensitive detection of trace p-DHB in various environmental water samples.
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MICROCHIMICA ACTA
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2019
·Vol. 186
·期 3
·1-9
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IF 5.479
Ma Yujun,Yu Ying,Lin Bixia,Zhang Li,Cao Yujuan,Guo Manli
Copper nanoclusters (CuNCs) were synthesized starting from glutathione and copper(II) nitrate. They show blue fluorescence peaking at 432 nm when excited at 334 nm. In the presence of o -phenylenediamine (OPD), the blue fluorescence is decreased, but a yellow fluorescence appears with a peak at 557 nm. UV-visible absorptiometry, fluorometry and fluorescence lifetime measurements were used to show that OPD is oxidized by the small fraction of copper(II) ions present in the CuNCs to form the oxidized form of o -phenylenediamine (oxOPD) which displays weak yellow fluorescence, while the blue fluorescence decreases. The ratio of fluorescences at 557 and 432 nm increases linearly in the 0.15 to 110 μg·L −1 OPD concentration range, and the detection limit is 93 ng·L −1 . Compared to the method based on the use of dissolved Cu(II), the employment of CuNCs reduces the detection limit by a factor of 40. The method was applied to the determination of OPD in spiked environmental water and industrial wastewater samples. Recoveries ranged from 96.8 to 100.3%.
Schematic presentation of a ratiometric fluorometric method for detection of o-phenylenediamine (OPD) based on copper nanoclusters (CuNCs). OPD is oxidized by Cu 2+ present in CuNCs to form the oxidized form of o -phenylenediamine (oxOPD). FRET occurred between oxOPD and CuNCs, and the F 557 /F 432 value is amplified.
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FUEL PROCESSING TECHNOLOGY
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2019
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IF 4.507
Tao Xie,Jing-Pei Cao,Chen Zhu,Xiao-Yan Zhao,Ming Zhao,Yun-Peng Zhao,Xian-Yong Wei
Selectively cleaving the C O bonds in lignin to produce aromatic products are challenging problems. Currently, catalytic hydrogenolysis of C O bonds in lignin requires harsh conditions. Herein, selectively cleaving C O bond of benzyl phenyl ether (BPE) was studied over Pd/AC, Ru/AC and Ni/AC. Among these catalysts, Pd/AC efficiently cleaved C O bond in BPE under super mild conditions (25 °C, 2 h and 0.1 MPa H 2 ). The products were toluene and phenol without hydrogenation of the aromatic ring . The main competitive step of hydrogenolysis and hydrogenation is sensitive to reaction temperature over Pd catalyst. A mild temperature is preferred for hydrogenolysis, since the H species nearby the oxygen atom are more strongly adsorbed than nearby the benzene rings . With the different H-donor solvents, the highest conversion of BPE was obtained in isopropanol. Based on the experiments, the reactions occurred via cleavage of the C aliphatic -O bond in BPE and the synergetic effects between the H from absorbed H 2 on the surface of the Pd and the intermediates radicals of benzyl and phenoxy should be the key points to such an optimum result.
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CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Jinhong Fan,Hehe Qin,Simin Jiang
Peroxymonosulfate (PMS) is an alternative to hydrogen peroxide in advanced oxidation processes. Herein, we present a simple one-pot synthetic approach for the Mn-doped graphite phase carbon nitride (g-C 3 N 4 ) materials and make it as a catalyst to activate PMS for acetaminophen (ACT) degradation. Fabricated Mn-g-C 3 N 4 composites (MnCN) were characterized by SEM, EDS, XRD, XPS, and FTIR. Results showed that Mn was uniformly dispersed in the structure of g-C 3 N 4 mostly in the form of Mn-N coordination. The effects of pH, contents of doped Mn, catalyst dosage, and reusability of catalyst and corresponding kinetic study were conducted to determine the catalytic performance of MnCN. High reaction efficiency was obtained in a wide pH range of 3.2–9. 100% removal of ACT in 15 min under optimized conditions with initial pH 6.5, 0.8 g/L of PMS and 200 mg/L of catalyst of 0.5-MnCN. Additionally, the reaction mechanism of the PMS/MnCN system was investigated using the electron spin resonance technique, quenching studies as well as different organics with electron-donating or electron-withdrawing groups. No PMS decomposition was detected without substrates. No inhibition effect by ethanol or tert -Butyl alcohol and complete inhibition effect by benzoquinone and partly by furfuryl alcohol, as well as ESR spectrum of TEMP- 1 O 2 were observed, suggesting that the activation of PMS proceeded in a new way, which is different from traditional sulfate radical-based advanced oxidation processes. A possible mechanism was proposed for ACT removal. PMS was first bounded to Mn-N sites to generate the superoxide anion. Then singlet oxygen produced by superoxide anion would react with ACT by replacing the electron-donating group of acylamino.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2018
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IF 5.091
Sijia Wu,Hong-Juan Zhao,Chao-Fan Li,Jing Liu,Wenda Dong,Heng Zhao,Chao Wang,Yang Liu,Zhi-Yi Hu,Lihua Chen,Yu Li,Bao-Lian Su
Graphitic carbon nitride (g-C 3 N 4 ) is a visible light active semiconductor. However, low conductivity and high recombination rate of photogenerated electrons and holes limit its application in photocatalysis. In this work, we design and synthesize hierarchically porous zinc oxide/graphitic carbon nitride (ZnO/g-C 3 N 4 ) microspheres with type-II heterojunction to effectively degrade rhodamine B (RhB) via increasing the charge-separation efficiency. The ultraviolet-visible (UV–Vis) absorption spectra, Mott-Schottky plots and valence band X-ray photoelectron spectroscope confirm the formation of type-II heterojunction between ZnO nanocrystals and g-C 3 N 4 nanosheets. As a result, the 1.5-ZnO/g-C 3 N 4 composite (the mass ratio of zinc acetate dihydrate to g-C 3 N 4 is 1.5) exhibits the highest photocatalytic activity with good stability and higher photocatalytic degradation rate comparing to pure g-C 3 N 4 and pure ZnO. In addition, our results confirm that O 2 − and h + are the main active species for ZnO/g-C 3 N 4 in degradation of RhB.
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SCIENCE OF THE TOTAL ENVIRONMENT
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2018
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IF 4.61
Wuhui Luo,Jiping Ouyang,Philip Antwi,Meng Wu,Zhiqiang Huang,Weiwei Qin
Butane-1,4-bis(dodecyl dimethyl ammonium bromide) (gBDDA) and dodecyl trimethyl ammonium bromide (DTMA) in same stoichiometric amounts were applied to modify montmorillonite (Mt) under microwave and ultrasound conditions. The composition and structure of products were obtained through multiple characterizations including XRD, FTIR , TG/DTG, SEM, TEM , and N 2 adsorption/desorption measurements, and the adsorption performance of chromate and phenol on these products were also investigated. Intercalations of gBDDA and DTMA into interlayer space of Mt were observed, but the amount of anchored modifier on the external surface was larger for gBDDA compared with DTMA when the stoichiometric amount of modifier larger than 1.0 times cation exchange capacity of Mt was added. Although there was no significant difference in morphology among products, the interlayer space distance, specific surface area, and pore size distribution were closely associated with the species and amount of applied modifier. Adsorption of phenol on products through partition mechanism relied on not only organic content, but also the configuration of modifier. Meanwhile, adsorption of chromate mainly depended on the presence of counter ion (bromide), which accounted for the high adsorption capacity and initial adsorption rate on gOMt-0.75. The fitting parameters of adsorption results using pseudo-second order model and Freundlich model suggested that gBDDA-modified Mt could sequester phenol or chromate in the faster manner with higher affinity. Compared with the conventional surfactant such as DTMA, the study revealed that, using gemini surfactant such as gBDDA to modify Mt would significantly reduce or even has the potential to eradicate the secondary pollution by modifier release during adsorption process. This study provides a new direction for Mt modification intended to be used as adsorbents to treat polluted water with high standards such as drinking water .
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2018
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IF 5.091
Junyan Kuang,Zipeng Xing,Junwei Yin,Zhenzi Li,Qi Zhu,Wei Zhou
Ti 3+ self-doped single-crystalline SrTiO 3−x nanocubes acting as molecular bricks are successfully assembled onto Ti 3+ self-doping single-crystalline TiO 2−x (B) nanorods through an effortless two-step hydrothermal process coupled with an in situ solid-state chemical reduction method. SrTiO 3−x nanocubes act as molecular bricks, which are uniformly assembled onto the surface of TiO 2−x (B) nanorods due to lattice matching. The band gap of the resultant SrTiO 3−x /TiO 2−x (B) sample is ∼2.97 eV, which exhibits excellent photocatalytic performance for the reduction of Cr(VI) and hydrogen production under visible light. The apparent rate constant k value for the photocatalytic reaction of SrTiO 3−x /TiO 2−x (B) for Cr(VI) reduction is ∼8 times higher than that of white TiO 2 (B). The photocatalytic hydrogen production rate for SrTiO 3−x /TiO 2−x (B) is ∼160.2 μmol g −1 h −1 , which is ∼5 times higher than that of white TiO 2 (B). The enhanced photocatalytic activity can be considered to be caused by a synergetic effect of heterojunction formation and the introduction of Ti 3+ self-doping, which can not only facilitate the separation of photogenerated charge carriers between TiO 2−x (B) and SrTiO 3−x , but also broaden the photoresponse from the UV to visible-light region.
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危险品化学品经营许可证（带存储）