ACS Catalysis
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2018
·
IF 11.384
Xiaoqin Sun,Yongli Mi,Feng Jiao,Xiaoxiang Xu
Solar water splitting into H2 and O2 upon a particulate photocatalyst relies on significant advances in material engineering where a number of important properties such as optical absorption, charge transportation, defect level, etc. can be manipulated. In this work, we have gained control over these properties for the wide band gap semiconductor Sr2TiO4 and successfully actualized water splitting under visible light illumination. This has been realized by codoping La/N into the laminated perovskite structure of Sr2TiO4. Strong visible light absorption as far as 650 nm can be tailored by varying the La/N content in Sr2–xLaxTiO4–yNy (0 ≤ x ≤ 0.5). Optimal photocatalytic H2 and O2 production has been achieved at x = 0.2, 0.3 and outweighs that of a number of typical perovskite oxynitrides. These activities are a function of several important parameters for photogenerated charges (e.g., concentration, mobility, and lifetime) which are all linked to La/N codoping levels. More strikingly, overall water splitting has been achieved at x = 0.2 with Rh/Cr2O3 as a cocatalyst. Defects such as Ti3+ species play a negative role in the photocatalytic activity, as they strongly promote charge recombination and shorten the electron lifetime. Theoretical calculations reveal the crucial role of N in uplifting the valence band maximum of Sr2TiO4 by hybridization with O 2p orbitals. La, therefore, balances the charge discrepancies induced during N/O replacements which would otherwise be unfeasible for substantial doping. Our calculations also suggest that Sr2TiO4 has a 2D charge transportation character which is extremely useful for charge separations.
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JOURNAL OF CATALYSIS
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2018
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IF 6.759
Weiyou Zhou,Qianyun Tao,Fu'an Sun,Xinbai Cao,Junfeng Qian,Jie Xu,Mingyang He,Qun Chen,Jianliang Xiao
NiMn layered hydroxide compounds have been found to be efficient catalysts for the oxidative dehydrogenation of N-heterocycles by molecular oxygen under mild conditions. Various tetrahydroquinoline derivatives and some other N-heterocycles have been found to be tolerated by the catalytic system. A synergistic effect between Ni and Mn has been observed in the reaction. A kinetic study concluded that the dehydrogenation of 1,2,3,4-tetrahydroquinoline is a first-order reaction, and an apparent activation energy of 113 kJ/mol has been obtained. A probable reaction mechanism comprising an imine intermediate has been proposed according to the obtained results and XPS analysis. The key catalytic site for the dehydrogenation is thought to be Mn 3+ , which could be stabilized by Ni 2+ in the hydrotalcite structure.
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NEW JOURNAL OF CHEMISTRY
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2018
·Vol. 42
·期 14
·11334-11340
·
IF 3.201
Jingjing Kang,Yakun Tang,Shasha Gao,Lang Liu
In this research, a series of one-dimensional controllable crosslinked polymers with the different mass ratios of 4-vinylbenzychloride (VBC) and divinyl benzene (DVB) was prepared via cationic polymerization, and the polymers were grafted with the functional group N-methyl-D-glucamine (NMDG) for boron removal. The optimum polymeric mass ratio and a series of boron adsorption performances were studied. The maximum adsorption capacity was 18.15 mg g−1, of which 94% was retained after 4 cycles. Meanwhile, different pH values had negligible effect on the boron adsorption capacity, which was favorable for the removal of boron from its aqueous solution in a wide pH window. In addition, a magnetic adsorbent was prepared by the combination of Fe3O4 nanoparticles and the polymer, which provided an effective way to collect and recover adsorbents from their aqueous solutions.
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JOURNAL OF MATERIALS SCIENCE
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2018
·Vol. 53
·期 13
·9690-9700
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IF 2.993
Huang Jinxin,Wang Jinglun,Zhong Haoxiang,Zhang Lingzhi
N -cyanoethyl polyethylenimine (CN-PEI) is synthesized by modifying polyethylenimine (PEI) with acrylonitrile through a Michael addition reaction. Depending on cyanoethylation level, CN-PEI can be obtained as a form of solution, micro-emulsion or emulsion in water. CN-PEI micro-emulsion is investigated as water-soluble binder for the application of lithium iron phosphate (LFP) cathode in lithium-ion batteries. CN-PEI binder not only maintains the outstanding dispersion capability of PEI but also exhibits an excellent adhesion strength and higher ionic conductivity because of the introduction of polar cyano groups. As a result, CN-PEI binder can effectively maintain the mechanical integrity and decrease the polarization of LFP electrode during the operation of the battery. LFP electrode with CN-PEI binder exhibits good cycle stability and enhanced rate performance delivering a capacity of 99.6% at a rate of 0.5 C after 100 cycles and a high discharge capacity of 102.4 mAh g −1 at 5 C.
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CERAMICS INTERNATIONAL
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2018
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IF 3.057
Hanqin Liang,Huilu Guo,Jinwei Yin,Kaihui Zuo,Yongfeng Xia,Dongxu Yao,Jian Zhang,Yuping Zeng,Shiwei Wang
Transparent AlON ceramics were bonded with Lu-Al-Si-O-N oxynitride glass interlayer at 1450 °C in nitrogen atmosphere in this investigation. The Lu-Al-Si-O-N oxynitride glass showed good wettability on the AlON substrate and had strong interface adhesion with each other. The joining process had no detrimental effect on the in-line transmittance of transparent AlON ceramics but caused slight decrease of flexural strength due to the partial decomposition. The bonding strength of AlON/AlON joint was 142.7 ± 6.3 MPa at room temperature and 110.1 ± 9.6 MPa at 1200 °C in situ, which were comparable with those of the parent AlON ceramics. Some Lu 2 Si 2 O 7 grains crystallized out from the glass interlayer after joining.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Bin Wang,Tie-yan Chang,Zhao Jiang,Jin-jia Wei,Yong-hai Zhang,Sen Yang,Tao Fang
Through systematical experiments, a comparative study was conducted concerning several graphene-supported noble metal catalysts for dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC). It was found that the catalytic activity of the prepared graphene-supported noble metal catalysts was following the order of Pd > Pt > Rh > Ru > Au for the dehydrogenation process. Pd supported on reduced graphene oxide (rGO) prepared by one-pot in situ synthesis has much more excellent catalytic performance than other kinds of catalysts investigated for comparison, simultaneously the using amount of noble metals can obviously be decreased. To be specific, at 453 K, the final dehydrogenation product catalyzed by the novel catalyst of Pd/rGO is N-ethylcarbazole (NEC) and the process selectivity was increased from 44.77% (commercial Pd/Al 2 O 3 ) to 97.65%, as well as the dehydrogenation ratio reached 99.14%. In addition, the novel catalyst is also superior to other reported catalysts in terms of dehydrogenation performance of 12H-NEC. Its dehydrogenation activity at 443 and 433 K of Pd/rGO was tested and the catalytic performance keeps stable at the two temperatures. Based on the experimental data, kinetic calculation was carried out and some fundamental parameters regarding reaction kinetics was obtained.
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Frontiers of Chemical Science and Engineering
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2018
·Vol. 12
·期 3
·346-357
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IF 2.643
Zhang Chao,Lu Chenbao,Bi Shuai,Hou Yang,Zhang Fan,Cai Ming,He Yafei,Paasch Silvia,Feng Xinliang,Brunner Eike,Zhuang Xiaodong
Porous polymers have been recently recognized as one of the most important precursors for fabrication of heteroatom-doped porous carbons due to the intrinsic porous structure, easy available heteroatom-containing monomers and versatile polymerization methods. However, the heteroatom elements in as-produced porous carbons are quite relied on monomers. So far, the manipulating of heteroatom in porous polymer derived porous carbons are still very rare and challenge. In this work, a sulfur-enriched porous polymer, which was prepared from a diacetylene-linked porous polymer, was used as precursor to prepare S-doped and/or N-doped porous carbons under nitrogen and/or ammonia atmospheres. Remarkably, S content can sharply decrease from 36.3% to 0.05% after ammonia treatment. The N content and specific surface area of as-fabricated porous carbons can reach up to 1.32% and 1508 m 2 ∙g –1 , respectively. As the electrode materials for electrical double-layer capacitors, as-fabricated porous carbons exhibit high specific capacitance of up to 431.6 F∙g –1 at 5 mV∙s –1 and excellent cycling stability of 99.74% capacitance retention after 3000 cycles at 100 mV∙s –1 . Furthermore, as the electrochemical catalysts for oxygen reduction reaction, as-fabricated porous carbons presented ultralow half-wave-potential of 0.78 V versus RHE. This work not only offers a new strategy for manipulating S and N doping features for the porous carbons derived from S-containing porous polymers, but also paves the way for the structureperformance interrelationship study of heteroatoms codoped porous carbon for energy applications.
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MOLECULES
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2018
·Vol. 23
·期 7
·1521
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IF 3.098
Xiangmin Song,Chunjuan Liu,Peiqi Chen,Hao Zhang,Ranfeng Sun
Natural products are an important source of pesticide discovery. A series ofN-amino-maleimide derivatives containing hydrazone group were designed and synthesized based on the structure of linderone and methyllinderone which were isolated fromLindera erythrocarpaMakino. According to the bioassay results, compounds2and3showed 60% inhibition against mosquito (Culex pipiens pallens) at 0.25 µg·mL−1. Furthermore, the results of antifungal tests indicated that most compounds exhibited much better antifungal activities against fourteen phytopathogenic fungi than linderone and methyllinderone and some compounds exhibited better antifungal activities than commercial fungicides (carbendazim and chlorothalonil) at 50 µg·mL−1. In particular, compound12exhibited broad-spectrum fungicidal activity (>50% inhibitory activities against 11 phytopathogenic fungi) and compounds12and14displayed 60.6% and 47.9% inhibitory activity againstRhizoctonia cerealisat 12.5 µg·mL−1respectively. Furthermore, compound17was synthesized, which lacks N-substituent at maleimide and its poor antifungal activity againstSclerotinia sclerotiorumandRhizoctonia cerealisat 50 µg·mL−1showed that the backbone structure ofN-amino-maleimide derivatives containing hydrazone group was important to the antifungal activity.Keywords:maleimide;linderone;methyllinderone;antifungal activity
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PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2018
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IF 3.649
Yujing Chen,Chuang Li,Xiao Chen,Yan Liu,Changhai Liang
Highly crystallized ZSM-23 zeolite samples were synthesized by employing the dual structure directing agents pyrrolidine (PY) and isopropylamine (IPA). The existence of two types of structure directing agents widened the synthesis composition ratio range and speeded up the crystallization. The samples obtained showed larger micropore surface areas and volumes compared with the products synthesized with single SDA. It was found that the use of the dual-structure directing agent had no effect on the total acidity but altered the acid site distribution where more weak and medium acidic sites were exposed and was found to be more suitable for n-hexadecane hydroisomerization. The bifunctional catalysts prepared from the supports using the dual-structure directing agent showed excellent catalytic performance under certain reaction conditions. It was noteworthy that Pt/PI-200 (Pt supported on the dual-structure directing agent with a SiO 2 /Al 2 O 3 ratio of 200) showed a constant selectivity to iso-hexadecane ca. 69% with contact time of 0.75 min and longer.
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mAbs
·
2018
·
IF 5.165
De-zhi Li,Bing-nan Han,Rui Wei,Gui-yang Yao,Zhizhen Chen,Jie Liu,Terence C.W. Poon,Wu Su,Zhongyu Zhu,Dimiter S. Dimitrov,Qi Zhao
Site-specific conjugation of small molecules to antibody molecules is a promising strategy for generation of antibody-drug conjugates. In this report, we describe the successful synthesis of a novel bifunctional molecule, 6-(azidomethyl)-2-pyridinecarboxyaldehyde (6-AM-2-PCA), which was used for conjugation of small molecules to peptides and antibodies. We demonstrated that 6-AM-2-PCA selectively reacted with N-terminal amino groups of peptides and antibodies. In addition, the azide group of 6-AM-2-PCA enabled copper-free click chemistry coupling with dibenzocyclooctyne-containing reagents. Bifunctional 6-AM-2-PCA mediated site-specific conjugation without requiring genetic engineering of peptides or antibodies. A key advantage of 6-AM-2-PCA as a conjugation reagent is its ability to modify proteins in a single step under physiological conditions that are sufficiently moderate to retain protein function. Therefore, this new click chemistry-based method could be a useful complement to other conjugation methods.
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ELECTROCHIMICA ACTA
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2018
·
IF 5.116
Mingquan Liu,Silu Huo,Min Xu,Linlin Wu,Mingjie Liu,Yifei Xue,Yi-Ming Yan
Nitrogen and sulfur co-doped carbon (NSC) is considered as a promising electrode material for supercapacitors (SCs). However, the specific capacitance and the rate performance of NSC are not satisfied for practical applications due to its inappropriate structural properties. Herein, we report the structural engineering of NSC by optimizing pore structure to obtain an ordered hierarchical pore network. The as-prepared NSC possesses a high gravimetric capacitance of 322 F g -1 at the current density of 1.0 A g −1 and retains 206 F g −1 (64% of its capacitance at 1.0 A g −1 ) at the high current density of 100 A g −1 . Moreover, it reveals an excellent cycling performance with ∼93.4% capacitance retention after 10000 cycles at the current density of 20 A g −1 . An assembled symmetric supercapacitor (SC) shows a remarkable energy density of 11.4 Wh kg −1 and a high power density of 12.9 kW kg −1 . The outstanding performances of NSC electrodes benefit from the efficient ion diffusion and fast charge transfer. This work paves a way to rationally design and engineer the structure of NSC for achieving both high rate capability and high specific capacitance for SCs applications.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2018
·Vol. 165
·期 7
·H348
·
IF 3.662
Le Wang,Hangjia Shen,Sanshuang Gao,Xamxikamar Mamat,Guangzhi Hu
As an excellent catalyst toward hydrogen peroxide reduction, Fe-based nanomaterial like Fe-N-C configuration is promising candidate to be used for H2O2 sensing. In this work, a novel N-doped mesoporous carbon by atomically dispersed Fe-N dopant composite modified electrode (Fe/NOMC) was prepared by hard template approach and then fabricated non-enzymatic sensor was used for H2O2 determination. The morphology and property of Fe/NOMC composite were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), small angle X-ray diffraction (XRD) spectrum and nitrogen-sorption measurement, respectively. The electrochemical sensing performance of the Fe/NOMC composite modified glassy carbon electrode (GCE) was studied by cyclic voltammetry and chronoamperometry methods. An excellent performance toward hydrogen peroxide reduction was achieved in a wide range of 8–23000 μM, with limitation of detection (LOD) about 5 μM and a correlation coefficient of 0.998, as well as a short response time (2 s) and good selectivity.
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