ChemistrySelect
·
2024
·Vol. 9
·期 36
·e202401875
·
IF 1.9
Haonan Li,Chenping Gao,Qingjie Liu,Yanchun Guo,Yufen Zhao
Graphical We report here a new I 2 /H 2 O 2 co-catalyzed oxidative [4+1] cyclization of benzaldehyde with 2-(aminomethyl)pyridine or o -phenylenediamine/2-aminothiophenol to provide various substituted imidazo[1,5- a ]pyridines and benzimidazoles/thiazole via C(acyl)−N bond construction. Some of heterocyclic products exhibit blue luminescence properties, as well as large Stokes shifts, eminent fluorescence quantum yields (64 %) and long fluorescence lifetimes. An efficient I 2 (10 mmol %)/H 2 O 2 mediated oxidative formal [4+1] cyclization of 2-pyridinemethylamine or o -phenylenediamine (2-aminobenzenethiol) with benzaldehyde via C−N bond formation has been developed. This strategy provides a straightforward approach to imidazo[1,5- a ]pyridines, iodo-substituted imidazo[1,5- a ]pyridines and benzimidazole (benzothiazole) derivatives in yields ranging from 60 % to 98 %, respectively. Several heterocyclic products exhibit promising blue luminous performance with satisfactory fluorescence quantum yields of up to 64 %, large Stokes shifts, and a longer lifetime (7.35 ns). The band gap energies obtained from DFT are also consistent with the absorption spectra.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2015
·
IF 2.947
Cheng Meng,Xingeng Ding,Junchuan Zhao,Chunrong Ren,Huiqin Fu,Hui Yang
Rare-earth phosphates (REPO 4 ) represent one candidate to contain minor actinides separated from used nuclear fuel. In this work, the Gd 1 − x Yb x PO 4 (0 ≤ x ≤ 1) series is synthesized via conventional solid-state reaction using Gd as the surrogate for trivalent actinides (Am, Cm), with microstructure/phase structure characterized by XRD , XPS, HRTEM and SEM as well. Solid solutions of monazite- and xenotime-type compounds are observed in the system. The structural boundary between two phases is based on the experimental temperature. The monazite → xenotime transformation is most likely to occur on a (2 0 0) monazite plane along the [0 2 0] zone. The pure xenotime-type crystalline phase with Gd 0.9 Yb 0.1 PO 4 composition is obtained at 1600 °C.
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JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Yunchuan Pu,Ziqi Yang,Vanessa Wee,Zhongjie Wu,Zhongyi Jiang,Dan Zhao
Membrane-based separation technologies are promising for various applications such as carbon capture and storage (CCS). Herein, we report the preparation and performance of mixed matrix membranes (MMMs) for carbon dioxide (CO 2 ) separation. The MMMs comprise amino-functionalized metal-organic framework (MOF) nanosheets (NUS-8-NH 2 ) dispersed in the polymer of intrinsic microporosity 1 (PIM-1). Specifically, the MOF nanosheets were synthesized through a bottom-up method and introduced into the PIM-1 matrix to fabricate NUS-8-NH 2 /PIM-1 MMMs. The uniformly dispersed MOF nanosheets could afford additional fast transport pathways through intra-flake pores and inter-flake nano-channels. Moreover, the amino groups could enhance CO 2 transport within NUS-8-NH 2 /PIM-1 MMMs. In addition, hydrogen bonding between the NUS-8-NH 2 filler and PIM-1 matrix improved interfacial compatibility. Therefore, the as-prepared MMMs could achieve a high filler loading of 15 wt% without sacrificing separation performance. Compared with the pure PIM-1 membrane, the MMM with 10 wt% NUS-8-NH 2 showed CO 2 permeability of ∼14000 Barrer and a CO 2 /N 2 selectivity of ∼30, surpassing the 2008 Robeson's upper bound.
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iScience
·
2021
·
IF 5.458
Mingwei Weng,Zihao Zhang,Francis Okejiri,Yue Yan,Yubing Lu,Jinshu Tian,Xiuyang Lu,Siyu Yao,Jie Fu
Catalytic transfer hydrogenation (CTH) of biomass-derived furfural (FAL) to furfuryl alcohol is recognized as one of the most versatile techniques for biomass valorization. However, the irreversible sintering of metal sites under the high-temperature reaction or during the coke removal regeneration process poses a serious concern. Herein, we present a silicalite-1-confined ultrasmall CuO structure (CuO@silicalite-1) and then compared its catalytic efficiency against conventional surface-supported CuO structure (CuO/silicalite-1) toward CTF of FAL with alcohols. Characterization results revealed that CuO nanoparticles encapsulated within the silicalite-1 matrix are ∼1.3 nm in size in CuO@silicalite-1, exhibiting better dispersion as compared to that in the CuO/silicalite-1. The CuO@silicalite-1, as a result, exhibited nearly 100-fold higher Cu-mass-based activity than the CuO/silicalite-1 counterpart. More importantly, the activity of the CuO@silicalite-1 catalyst can be regenerated via facile calcination to remove the surface-bound carbon deposits, unlike the CuO/silicalite-1 that suffered severe deactivation after use and cannot be effectively regenerated.
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PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2012
·Vol. 29
·期 10
·1388-1392
·
IF 0.991
He Minqiang,Pan Aixia,Xie Jimin,Li Huamin,Yuan Xinhua,Cheng Xiaonong,Chen Min
A novel one-pot catalytic synthesis of 1-benzoylpyrene through acylation of pyrene with benzoic anhydride catalyzed by several heteropoly acids (HPAs) was investigated. Pure 1-benzoylpyrene was obtained and its structure was identified by GC/MS, FT-IR and 1 H NMR spectra. Silica-supported phosphotungstic heteropoly acid (PW/SiO 2 ) was found to be the most active catalyst in the acylation. The yield and the selectivity of 1-benzoylpyrene were up to 62.5% and 100%, respectively. The effects of experimental parameters on the catalytic acylation reaction, and the possibility of reusability of PW/SiO 2 catalyst were studied. PW/SiO 2 catalyst is easily separable from the reaction mixture and reusable without loss of its activity.
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Catalysts
·
2022
·Vol. 12
·期 7
·685
·
IF 4.501
Hao Dong,Cheng-Hua Xu,Fang-Lu Yang,Lei Du,Chen-Long Liu,Wen-Jing Chen,Lin Wang
Ca–Zr–Sn composite oxides catalysts for 1,4-butanediol (BDO) selective dehydration to 3-butene-1-ol (BTO) are synthesized by impregnation and co-precipitation in the present work. The results show that Ca–Zr–Sn catalysts prepared from co-precipitation by using NaOH-Na2CO3mixing alkali solution as precipitant exhibit an excellent catalytic property for BDO dehydration to BTO. For instance, Ca–Zr–Sn oxide with Ca/Zr and Sn/Zr molar ratio of 0.68 and 0.28 calcined at 650 °C gives a BDO conversion and BTO selectivity of about 97% and 82%, respectively, and exhibits no deactivation during 1000 h scale-up experimental testing. X-ray diffraction results indicate that catalytic active centers for BDO dehydration to BTO are from Ca0.15Zr0.85O crystal phase. NH3- and CO2-temperature programmed desorption prove that the surface of obtained catalysts can provide a large amount of acid and base sites simultaneously. FT-IR spectra of pyridine-adsorbed samples show that acid sites on the surface of Ca–Zr–Sn oxide catalyst mainly exist in a state of Lewis acid, which activates terminal -OH groups of BDO molecule through complexing. The activated -OH interacts with β-H activated on base sites O2−anions relative to Ca species, thereby the CH2=CH- bonds are produced through dehydration to form BTO.
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MOLECULES
·
2022
·Vol. 27
·期 22
·7959
·
IF 4.927
Guan Lin,Juntao Gao,Shenghua Shang,Huanbo Zhang,Qiangke Luo,Yutong Wu,Yong Liu,Xingjiang Chen,Yan Sun
The occurrence of crop fungal diseases is closely related to warm environmental conditions. In order to control the release of fungicides in response to warm conditions, and enhance the efficacy, a series of thermo-responsive fungicide-loaded nanoparticles were developed. The fungicide azoxystrobin, solvent DEP, emulsifier Tween 80 and thermo-responsive component TDA were combined to create thermal-response oil phases, conditions for emulsification were then optimized. LDLS, zeta potential, FTIR, DSC, TGA, XRD, SEM and antifungal efficacy assays were carried out to investigate the characteristics and forming mechanism. The results indicated that the formula with 5 g azoxystrobin, 10 mL DEP, 6 mL Tween 80 and 2.5 g TDA constructed the proposed oil phase with the ability to transform from solid at 20 °C to softerned at 31.5 °C. Both DEP and TDA played key roles in interfering with the crystallization of azoxystrobin. The optimal T3t-c12 nanoparticles had a mean particle size of 162.1 nm, thermo-responsive morphological transformation between 20 °C and 30 °C, AZO crystal reforming after drying, the ability to attach to fungal spores and satisfied antifungal efficacy againstP. nicotianaPNgz07 andA. nigerA1513 at 30 °C. This report provides referable technical support for the construction of smart-release nanoparticles of other agrochemicals.
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
S.D. Zhou,Y.G. Wang,Y. Li,H. Wu,L. Zhu
The ternary (1− x )(0.8BiFeO 3- 0.2BaTiO 3 )- x K 0.5 Na 0.5 NbO 3 (0 ≤ x ≤ 0.5) solid solutions have been successfully synthesized by a solid-state reaction route. X-ray diffraction and Rietveld refinement studies reveal the phase transition from the rhombohedral and tetragonal phases to the single tetragonal phase with x increasing. The average grain size decreases initially and then increases as x increases, whereas the remnant magnetization shows an opposite trend and reaches the maximum value of ~2.09 emu/g at x = 0.3. An enhanced remnant polarization of ~8.6 μC/cm 2 appears at x = 0.3 due to the structure distortion and the decrement of defects. Moreover, the remanent polarization and the relative permittivity reach the maximum value of ~20.14 μC/cm 2 (10 Hz) and ~644 (1 kHz) at x = 0.5, respectively, and the corresponding dielectric loss decreases to the lowest value of ~0.022 (1 kHz). These results indicate that the properties of ternary BFO-BTO-KNN solid solutions can be modulated by adjusting the K 0.5 Na 0.5 NbO 3 content to adapt to different application needs.
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ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Guanying Dong,Jingjing Zhang,Zheng Wang,Jing Wang,Peixia Zhao,Xingzhong Cao,Yatao Zhang
Polydopamine-modified additives have been thus far widely used in the mixed matrix membranes (MMMs) for gas separation. However, very few reports focus on the polydopamine alone and investigate its contribution to the gas separation performance. Herein, the polydopamine-derived submicrospheres (PDASS) were paired with polymers of intrinsic microporosity (PIM-1) to fabricate high-performance gas separation membranes, through which the effects of PDASS on gas permeability and CO2/N2 separation performance were systematically investigated. The addition of PDASS provides a 1.6-fold enhancement in CO2/N2 selectivity together with acceptable gas permeability as compared to the original polymeric membrane. Such enhanced separation behavior is supposed to stem from the densified membrane microstructure induced by the strong intermolecular interactions between PIM-1 and PDASS (i.e., charge transfer, π–π stacking, and hydrogen bonding). Importantly, the physical aging behavior, as judged by gas permeability, is retarded for PIM/PDASS membranes after 4 months of testing.
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高影响因子
ChemElectroChem
·
2019
·Vol. 6
·期 17
·4681-4688
·
IF 3.975
Yu Huang,Rengui Xiao,Zhiming Ma,Weichen Zhu
Graphical In sync : The 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMImTfO) dual-graphite battery exhibits a high discharge plateau above 3.0 V, which originates from the synchronized de-intercalations of EMIm + and TfO − from the graphite cathode and anode, respectively. The battery can light up a red LED with 3.0 V standard voltage. In this work, a novel dual-graphite battery (DGB) based on a pure 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMImTfO) ionic liquid electrolyte is constructed. Within a charge/discharge voltage range of 1.0–3.9 V and at a current of 400 mA g −1 , batteries with dual-natural-graphite electrodes exhibit a high discharge plateau above 3.0 V with an initial discharge capacity of 46.2 mAh g −1 , delivering a capacity retention of 71.0 % after 100 cycles. Comparative studies between the natural graphite and the synthetic graphite (KS6) electrodes are also conducted. Charge-discharge tests reveal that the dual natural-graphite battery presents a higher discharge voltage plateau and better retention than the dual KS6-graphite battery. To confirm the principle of the dual-graphite systems, a cyclic voltammetry test is conducted. The results demonstrate that the EMIm + cation exhibits an even more stable intercalation/de-intercalation behavior than the TfO − anion. Further tests, including ex situ X-ray diffraction and ex situ Raman spectroscopy, are performed to reveal the mechanism of TfO − and EMIm + intercalation into graphite, both demonstrating a reversible process.
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ELECTROCHEMISTRY COMMUNICATIONS
·
2020
·
IF 4.333
Min Li,Ying Li
The conversion of solid Bi 2 O 3 to bismuth in a urea–1-methylimidazolium trifluoromethylsulfonate (urea–MIMTfO) electrolyte is studied for the first time. The electrochemical reduction behavior of solid Bi 2 O 3 was studied using a home-made graphite cavity working electrode. Cyclic voltammetry of the graphite cavity electrode confirms that solid Bi 2 O 3 is converted to metallic bismuth via a one-step process. Electrolysis experiments were carried out under constant voltages of 2.4 V, 2.6 V, and 2.8 V for various periods of time. Experimental results indicate that the urea–MIMTfO solution is a useful electrolyte for the electrochemical conversion of solid Bi 2 O 3 to metallic bismuth. This approach offers a green and straightforward method for the conversion of oxides to metals.
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高影响因子
SOLID STATE SCIENCES
·
2016
·
IF 2.041
Haoliang Xue,Zhuangzhang He,Yun Zhao,Qingze Jiao,Qin Wu,Hansheng Li
ZSM-5/KIT-1 composites were synthesized using an ionic liquid as a template. The structures and morphologies of as-obtained products were characterized using an infrared spectroscopy, X-ray diffractometer, N 2 adsorption/desorption, scanning electron microscopy and transmission electron microscopy . The resultant zeolites show a fully crystalline microporous MFI zeolite framework and a three-dimensional network of short worm-like channels. Mesopores and microspores of 4.2 and 0.8 nm in diameter coexist in the zeolite composites. Moreover, the ratio of ZSM-5 and KIT-1 could be simply adjusted by controlling the pre-crystalline time. We believe that the strategy for fabricating ZSM-5/KIT-1 through a simple method could potentially promote the large-scale production of zeolite composites.
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高影响因子
危险品化学品经营许可证（带存储）