Chinese Journal of Natural Medicines
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2014
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IF 0
Pei-Pei WANG,Guo-Wei ZHAO,Wen XIA,En-Ji HAN,Lan XIANG
This study was conducted to investigate the chemical constituents of Piper wallichii (Miq.) Hand.-Mazz. and evaluate their biological activity. Compounds were isolated by various column chromatographic methods, and their structures were elucidated on the basis of physical characteristics and spectral data. The 1, 1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity and acetylcholinesterase (AChE)-inhibitory activity of the compounds were evaluated. Five compounds were obtained and identified as 8- C -β-D-glucopyranosylkaempferol-3- O -β-D-glucopyranoside ( 1 ), 1, 2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3, 5-dimethoxy-4-hydroxyphenyl)- N 1 , N 2 -bis-[2-(4-hydroxyphenyl)ethyl]-2, 3-naphthalene dicarboxamide ( 2 ), goniothalactam ( 3 ), aristololactam A IIIa ( 4 ) and piperlonguminine ( 5 ). Compound 1 was a new flavonol C -glycoside, 2 was a rare lignanamide, which was isolated from the family Piperaceae for the first time, and compound 3 was isolated from this plant for the first time. Among them, 2 showed potent DPPH-scavenging activity, with IC 50 of 31.38 ± 0.97 μmol·L −1 ; Compounds 2 , 3 , and 4 showed AChE inhibitory activity at 100 μmol·L −1 , with inhibition rates of 28.57% ± 1.47%, 18.48% ± 2.41% and 17.4% ± 3.03%, respectively.
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PubMed
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2014
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IF 2.235
Qi-Ying Liu,Yu-He Liao,Tie-Jun Wang,Chi-Liu Cai,Qi Zhang,Noritatsu Tsubaki,Long-Long Ma
ZrP with large surface, mesoporous volume, and size was prepared. Its catalytic performance was evaluated in hydrolytic hydrogenation of cellulose to sorbitol/mannitol combined with commercial Ru/C. A significantly enhanced sorbitol/mannitol yield was obtained as compared with that of the water-soluble acidic phosphates and buffer solution of potassium acid phthalate combined with the same Ru/C. The enhanced yield was attributed to the Lewis and Brönsted acid on ZrP surface improving the surface’s absorption and activation for cellulose and accelerating the rate-determined hydrolysis step. The maximal sorbitol/mannitol yield of 63% and 81% could be obtained by using microcrystalline and ball milling cellulose as the feedstock, respectively. The ZrP combined with Ru/C was adaptable to the high concentrated cellulose and obtained 5.8 wt % of sorbitol/mannitol concentration. The remarkably enhanced cellulose hydrolysis by ZrP sharply decreased the use of Ru/C, which is significant for the essential application.
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高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Yixuan Song,Tingting Qiang,Ming Ye,Qiuyang Ma,Zhen Fang
Design an effective absorbent that has high surface area, and perfect recyclable is imperative for pollution elimination. Herein, we report a facile two-step strategy to fabricate magnetically separable 3-dimensional (3D) hierarchical carbon-coated nickel (Ni@C) nanocomposites by calcinating nickel based metal organic framework (Ni 3 (OH) 2 (C 8 H 4 O 4 ) 2 (H 2 O) 4 ). SEM and TEM images illuminate that the nanocomposites were constructed by 8 nm nickel nanoparticle encapsulated in 3D flake like carbon. The specific surface area of the obtained nanocomposites is up to 120.38 m 2 g −1 . Room temperature magnetic measurement indicates the nanocomposites show soft magnetism property, which endows the nanocomposites with an ideal fast magnetic separable property. The maximum adsorption capacity of the nanocomposites for rhodamine B is 84.5 mg g −1 . Furthermore, the nanocomposites also exhibit a high adsorption capacity for heavy metal ions. The adsorbent can be very easily separated from the solution by using a common magnet without exterior energy. The as-prepared Ni@C nanocomposites can apply in waste water treatment on a large-scale as a new adsorbent with high efficiency and excellent recyclability.
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高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Yuan Chen,Shanshan Jie,Congqiang Yang,Zhigang Liu
The development of highly active and efficient heterogeneous catalytic oxidation systems has become an attractive research area. In this study, nano cobalt-coordinated nitrogen-doped carbon catalysts (Co-N/C), which were prepared by the pyrolysis of cobalt porphyrin supported on carbon black precursor, were used as highly active catalysts for the oxidation of hydrocarbons with tert -butyl hydroperoxide as the oxidant. The results showed that the catalyst was efficient in the selective oxidation of a variety of saturated (including primary, secondary, and tertiary) C H bonds. The catalyst displayed the best catalytic performance, which was comparable to those for previously reported metal oxide catalysts and even better. The resultant Co-N/C catalysts were characterized in detail by XRD, nitrogen adsorption/desorption isotherms, TEM, SEM and XPS. The homogeneous distribution of the Co species and interactions between the Co-N species could improve the synergistic effect between the Co O, Co N and N C species, which led to their excellent catalytic performance. A first order kinetics was observed for the reaction with the apparent activation energy for ethylbenzene oxidation was 22.2 ± 2.1 kJ mol −1 .
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高影响因子
Molecular Catalysis
·
2024
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IF 3.9
Tao Liu,Youcai Zhu,Yue Mu,Xindi Feng,Zhen Liu
CO 2 -based polyols have a unique terminal hydroxyl group structure that makes them suitable for the production of high-performance polyurethane foams. Zn-Co double metal cyanides (DMC) are an important class of catalysts for the copolymerization reaction of CO 2 with propylene oxide (PO). In the DMC-catalyzed CO 2 /PO copolymerization to produce CO 2 -based polyols, the crucial role of chain transfer agents (CTAs) is emphasized. In this work, a high-performance composite CTA (c-CTA) was successfully developed by investigating various dicarboxylic acids and polypropylene glycol (PPG-400) as CTAs. This system combines the high reaction rate of the DMC/PPG-400 system with the high CO 2 insertion rate of the DMC/sebacic acid (SA) system, achieving 2-3 times higher activity than that of single CTA (PPG-400 or SA), reaching 0.5 kg/g. The molecular characteristics of the CO 2 -based polyols synthesized by different DMC/CTAs systems were analyzed by FTIR and 1 H NMR. The reasons for the high catalytic activity of the DMC/c-CTA system were elucidated by analyzing the hydrogen bond distribution in each DMC/CTA systems. Overall, this work provides a theoretical guidance for the development of novel CO 2 -based materials with high industrial application value.
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高影响因子
Journal of Physical Chemistry C
·
2024
·
IF 3.3
Jiao Wu,Jingxuan Cui,Aihu Feng,Kun Liu,Yun Yu
Introducing “spacer” materials into Ti3C2Tx layers is a powerful approach to reduce layer stacking and enhance the utilization of active sites in capacitive deionization (CDI). In this research, porous carbon spheres derived from polymethacrylates (PMMA) act as the “spacer” material, and the Ti3C2Tx/C composite is prepared through a straightforward technique of mixing followed by annealing. Through the cooperative effect of the “separation” of Ti3C2Tx nanosheets and the porous nature of the carbon spheres, Ti3C2Tx/C has a large specific surface area of 96.01 m2 g–1, a pore volume of 0.2306 cm3 g–1, and a well-developed mesoporous structure. Benefiting from the increased adsorption sites coupled with lower migration resistance, Ti3C2Tx/C achieves an ion adsorption capacity of 24.29 mg g–1 and ion adsorption rate of 0.0485 mg g–1 s–1 in 1000 μS cm–1 NaCl solution at 1.2 V, reflecting an increase of 76 and 166%, respectively, compared to m-Ti3C2Tx (13.8 mg g–1 and 0.0485 mg g–1 s–1). Besides, it is established that the ion adsorption process of Ti3C2Tx/C is more accurately described by the second-order kinetic module.
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高影响因子
FUEL
·
2024
·
IF 6.7
Shan Jiang,Qian Zhang,Xizi Lin,Wenjun Liu,Songbai Qiu,Riyang Shu
Hydrodeoxygenation (HDO) is an effective method for upgrading lignin-derived phenolic compounds into high-quality liquid fuels, and the support rational design of HDO catalysts is critical for boosting reaction efficiency. In this study, a series of Ni/Al 2 O 3 -C catalysts with different ratio of Al 2 O 3 and carbon components were proposed for the HDO of lignin-derived phenolic compounds. Ni/Al 2 O 3 -C-0.25 catalyst is screened for a superior HDO efficacy compared to the other catalysts, in which guaiacol can be completely converted at 220 °C, with 99.9 % cyclohexane selectivity produced at 4 h. Various characterizations for the catalysts were carried out, including BET, XRD, TEM, XPS and NH 3 -TPD. According to the characterization results, Ni/Al 2 O 3 -C-0.25 catalyst presents little dense Al 2 O 3 fiber structure, which favors the Ni metal dispersion and possesses the smallest Ni metal particle size (10.9 nm). This leads to the outstanding catalytic hydrogenation activity. Moreover, the specific interaction between Al 2 O 3 and carbon in Ni/Al 2 O 3 -C-0.25 catalyst results in the moderate acid property, which promotes the deoxygenation process of the intermediate products, as evidenced by the effective cleavage of C-O bond and the enhanced selectivity of cyclohexane products. The adaptation of Ni/Al 2 O 3 -C-0.25 catalyst to lignin-oil upgrade was also investigated, with a rise of hydrocarbon content from 6.1% to 47.5%. These results indicate that the catalysts with this composite support had the potential to upgrade lignin-derived phenolic compounds to superior grade hydrocarbon liquid fuels.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Jiawei Du,Mengyi Zhang,Peng Tang,Liwen Zhang,Xueying Zhao,Xiaolu Zhan,Bo Wang,Jianjun Zhao,Nana Liu,Guohua Wu,Xuyang Zhang
The development of low-frequency absorption materials is pivotal for the significant reduction of electromagnetic interference and the enhancement of the electromagnetic environmental quality. Further research is essential to deepen and expand the scope of low-frequency absorption studies. In this study, nanoscale CoFe/C composite materials were synthesized from cobalt-iron bimetallic metal-organic frameworks (MOFs) via a hydrothermal synthesis process, followed by heat treatment. The dispersion of CoFe alloy particles and the morphology of the composites were effectively controlled by modulating the cobalt-to-iron element ratio in the precursors, thereby optimizing the absorption capabilities in a mid-low frequency range. The prepared Co 3 Fe 7 /C composite achieved a notable minimum reflection loss (RL min ) of −55.05 dB in the C-band at a thickness of 3.46 mm, with an effective absorption bandwidth (EAB) of 2.2 GHz (5.40–7.60 GHz), covering 55 % of the C-band. Furthermore, at a thickness of 1.67 mm, the EAB was extended to 5.12 GHz. The nanoscale core-shell structured CoFe alloy/carbon composites demonstrate considerable potential as exceptional low-frequency absorption materials, due to their favorable dispersion, high magnetic responsiveness, and the presence of numerous heterogeneous interfaces.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Xinyu Wang,Shiqi Chen,Can Liu,Jiapeng Yue,Zhiwei Yang,Qian Ye,Hao Xu,Yujian Zhang,Xinyi Xing,Jing Zhang
In this study, the charge transfer capability of MoO 2 materials was significantly improved by introducing carbon materials in situ. The resulting MoO 2 -C material could accelerate the Fe(III)/Fe(II) redox cycle and promote the continuous generation of reactive oxygen species in Fenton-like system. The results suggested that MoO 2 -C exhibited significant co-catalytic activity against a variety of pollutants. Meanwhile, the mechanisms behind the Fe(III)/Fe(II) cycle and reactive oxygen species generation were clarified. Analysis indicated that the incorporation of carbon material provided a reduction active site for the reduction of Fe(III) to Fe(II) on the surface of molybdenum oxide, and also reduced the thermodynamic energy barrier associated with Fe(III) reduction. Furthermore, quenching experiments and electron paramagnetic resonance (EPR) technology demonstrated that hydroxyl radicals ( ∙ O H ) and singlet oxygen ( 1 O 2 ) rapidly degrade the target pollutants. Fe(II) was verified as the primary component responsible for peroxymonosulfate (PMS) and peroxydisulfate (PDS) activation. Additionally, the main generation pathway for 1 O 2 differed between the MoO 2 -C/Fe(III)/PDS and MoO 2 -C/Fe(III)/PMS systems. This study provides a new strategy to improve the iron reduction properties of metal oxide materials.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2024
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IF 3.5
Xiao-Chun Deng,Xiao-Dong Kang,Guo-Hua Zhang
The (TiZrHfNbTaMo)C-15 wt.% Co ceramics with excellent comprehensive properties were successfully prepared by vacuum liquid phase sintering. The effects of WC content on the grain size, microstructure, and mechanical properties were investigated. The results showed that WC was dissolved into (TiZrHfNbTaMo)C phase to form a seven-component solid solution, and the independent WC phase disappeared. The addition of WC improved the wettability between the ceramic phase and the metal phase and promoted the densification of the ceramics. In addition, WC played a role in refining grains and inhibiting the grains growth to a certain extent. The comprehensive properties of ceramics were improved by solid solution strengthening and high entropy effect. When the WC content was 5 wt.%, the toughness reached the maximum of 9.41 ± 0.15 MPa·m 1/2 , and the hardness of the ceramic with 10 wt.% WC achieved the highest value of 18.18 ± 0.20 GPa.
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MOLECULES
·
2025
·Vol. 30
·期 4
·808
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IF 4.6
Jinhai Cui,Dezhi Chen,Mengna Xie,Yongheng Zhou,Shuai Dong,Wei Wei
One method to enhance the electrochemical performance of carbon-coated Li2FeSiO4cathode material in lithium-ion batteries is to produce an ideal Li2FeSiO4precursor with minimal impurities. A novel precursor for Li2FeSiO4(Li2O·FeCO3·CH3OSiO2H) was synthesized through a methanol solvothermal reaction under stringent conditions (180 °C and 2.7 MPa), achieving a purity level of 93.2%. During synthesis, the new Li2FeSiO4precursor exhibits unique self-purification properties and maintains a fine morphology after annealing. The resulting carbon-coated Li2FeSiO4composites demonstrate a Brunauer–Emmett–Teller specific surface area of 102.4 m2/g and approximately 81% mesoporous volume, with 90% of the pore sizes measuring less than 39 nm. As a cathode material for lithium-ion batteries, this carbon-coated Li2FeSiO4exhibits initial specific capacities of 172.3 mAh/g (charge) and 159.3 mAh/g (discharge). Remarkably, nearly 50% of the theoretical specific capacity remains after 1300 cycles at a rate of 0.1 C. The excellent electrochemical performance of the carbon-coated Li2FeSiO4materials is demonstrated by their high lithium-ion diffusivity (DLi+) value of 1.26 × 10−11cm2/s. Additionally, the enormous capacities-controlled diffusion contribution, which accounts for 70% of the total diffusion at a rate of 1C, is noteworthy. This performance can be attributed to the high purity of the carbon-free Li2FeSiO4composite, which contains 91% Li2FeSiO4, as well as its favorable morphology.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
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IF 9.4
Qingwei Li,Kai Nan,Wei Wang,Hao Zheng,Kaikai He,Yan Wang
Electromagnetic (EM) pollution can disrupt the functioning of advanced electronic devices, hence it’s necessary to design EM wave absorbers with high-level absorption capabilities. The Ti 3 C 2 T x (MXene) is classified as a potential EM absorbing material; nevertheless, the lack of magnetic loss mechanism leads to its inadequate EM absorbing performance. On this basis, a novel composite design with promising EM absorption properties is hypothesized to be the integration of few-layer MXene and heterogeneous magnetic MOF derivatives (Fe 3 O 4 /C) with complementary advantages. Herein, we synthesized two-dimensional (2D) interfacial-polarization-enhanced MXene hybrid (Fe 3 O 4 /C/MXene) by electrostatic assembly. It is notable that the interfacial polarization is realized by adding a small amount of magnetic Fe 3 O 4 /C. Furthermore, the Fe 3 O 4 /C/ MXene demonstrates an astonishing effective absorption bandwidth (EAB) of 10.7 GHz and an excellent EM wave absorption performance (RL min ) of −66.9 dB. Moreover, the radar cross section (RCS) of Fe 3 O 4 /C/MXene is lower than −15.1 dB m 2 from −90° to 90° with a minimum RCS value of −52.6 dB m 2 at 32°. In addition, the significant attenuation of the EM wave is due to the synergistic effect of improved impedance matching, dielectric loss, and magnetic loss. Thus, the magnetized Fe 3 O 4 /C/MXene hybrid is expected to emerge as a strong contender for high-performance EM wave absorbers.
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高影响因子
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