JOURNAL OF CHEMICAL RESEARCH
·
2021
·
IF 0.782
Chun-Jing Li
We report a direct cross-coupling reaction between (het)aryl pivalates/tosylates and di(het)arylzinc species in 2-methyltetrahydrofuran/N-methyl pyrrolidone (1:1), which occurs via C–O bond cleavage under microwave irradiation. The reaction takes place smoothly in short reaction times without the addition of any catalyst or ligand. The reaction is suitable for a broad scope of substrates and exhibits good functional group compatibility, utilizes a simple work-up procedure, and gives the desired products in high purity.
研究领域:
有机化学
·
合成化学
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DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2023
·
IF 3.6
Jianbo Tang,Junhua Kong,Hui Xu,Zhi-Jiang Jiang,Yifan She,Jianfei Bai,Bencan Tang,Jia Chen,Zhanghua Gao,Kun Gao
Silver-catalyzed deuteration of nitroaromatics has been achieved using D2O as the deuterium source. Distinct from the well-established directing group-guided hydrogen-isotope exchange, this protocol showed an interesting deuteration pattern, where considerable deuterium accumulation was observed around the aromatic rings. Controlling experiments suggested that the deuteration was initiated by a silver-promoted C–H activation. Therefore, a tentative two-stage deuteration mechanism involving aryl-silver species was proposed to explain the deuteration on meta- and para-positions.
研究领域:
有机化学
·
同位素化学
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DOI
PubMed
高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2014
·Vol. 52
·期 4
·2458-2463
·
IF 2.024
Zhou Xiaoli,Hao Tingfeng,Zhou Yiming,Tang Wen,Xiao Ying,Meng Xiaoxiao,Fang Xiang
Relationships of changes between major non-enzymatic antioxidant compounds and antioxidant capacities of tartary buckwheat during germination were evaluated by means of correlation analysis and principal component analysis in this paper. The changes of antioxidant compounds, including vitamin C, vitamin E, flavonoids, carotenoids, and chlorophyll, and antioxidant activities were detected. A good accumulation in the content of vitamin C (0.71 mg/g), total flavonoids (19.53 mg rutin/g), and rutin (11.34 mg/g) was found after 7-day germination, but germination decreased the vitamin E activity. Germination improved the activities of buckwheat extracts to scavenge DPPH, ABTS, and superoxide free radicals by 107, 144, and 88 %, respectively. Furthermore, the correlation and principal component analysis showed that the vitamin C, total flavonoids, and rutin contents were closely related positively with free radicals scavenging properties, indicating that the compounds which play a key role in the elevated antioxidant activities during germination consisted of vitamin C, total flavonoids, and rutin, but not vitamin E and quercetin.
研究领域:
食品科学
·
植物生理学
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DOI
PubMed
高影响因子
CARBON
·
2022
·
IF 11.307
Xilong Wang,Hongwei Zhu,Chen Yang,Jiajia Lu,Lirong Zheng,Han-Pu Liang
Single-atom Fe–N–C electrocatalysts are attracting more attentions as one most promising transition metal based single-atom catalyst towards the oxygen reduction reaction (ORR). However, the inaccessibility of internal Fe-N x active sites and insufficient stability hinder their large-scale application. Herein, a facile benzoate-assisted self-template strategy which could dramatically enhance the oxygen reduction reaction catalytic performance and stability of ZIF-8 derived atomically dispersed Fe–N–C catalysts (Fe-SA/Meso-C) is developed. The sodium benzoate used in the present work is effective for promoting the formation of Fe–N–C catalysts with denser accessible active sites as well as mesopores with diameters ranging from 2.5 to 5 nm. These structural advantages make the synthesized Fe-SA/Meso-C catalysts afford excellent electrocatalytic performance for the ORR in 0.1 M KOH with a positive half-wave potential (E 1/2 ) of 0.926 V vs. RHE and exceptionally high kinetic current density (J k ) of 92.5 mA cm −2 at 0.85 V. Beyond that, Fe-SA/Meso-C shows outstanding long-term stability with over 90% activity retain after 90 h chronoamperometry i-t test as well as superior tolerance to methanol crossover . More importantly, the assembled zinc-air battery with Fe-SA/Meso-C as the cathode material achieves a high peak power density of 166.2 mW cm −2 and a high specific capacity of 776.1 mA h g −1 . Our results reveal that small mesopores in atomically dispersed Fe–N–C electrocatalysts could facilitate mass transport, increase the accessibility of active sites and optimize the interface between electrolyte and carbon matrix, thus optimizing their electrocatalytic performance for the ORR. This work paves a way to the design and synthesis of stable single-atom electrocatalysts with optimized structure, electrochemical performance and promising applications.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Deliang Cheng,Lichun Yang,Renzong Hu,Jiangwen Liu,Renchao Che,Jie Cui,Yanan Wu,Wanyu Chen,Jianling Huang,Min Zhu,Yu-Jun Zhao
Developing anodes with a high and stable energy density for both gravimetric and volumetric storage is vital for high-performance lithium/sodium-ion batteries. Herein, an SnSe/few-layered graphene (FLG) composite with a high tap density (2.3 g cm–3) is synthesized via the plasma-milling method, in which SnSe nanoparticles are strongly bound with the FLG matrix, owing to both Sn–C and Se–C bonds, to form nanosized primary particles and then assemble to microsized secondary granules. The FLG can effectively alleviate the large stress generated from the volume expansion of SnSe during cycling based on its superstrength. Furthermore, as demonstrated by the density-functional theory calculations, the Sn–C and Se–C co-bonding benefitting from the formation of substantial vacancy defects on the P-milling-synthesized FLG enables strong affinity between SnSe nanoparticles and the FLG matrix, preventing SnSe from aggregating and detaching even after long-term cycling. As an anode for lithium-ion batteries, it exhibits high gravimetric and volumetric capacities (864.8 mAh g–1 and 1990 mAh cm–3 at 0.2 A g–1), a high rate (612.6 mAh g–1 even at 5.0 A g–1), and the longest life among the reported SnSe-based anodes (capacity retention of 92.8% after 2000 cycles at 1.0 A g–1). Subsequently, an impressive cyclic life (capacity retention of 91.6% after 1000 cycles at 1.0 A g–1) is also achieved for sodium-ion batteries. Therefore, the SnSe/FLG composite is a promising anode for high-performance lithium/sodium-ion batteries.
研究领域:
材料科学
·
储能
·
电化学
·
纳米材料
·
电池技术
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Qingfeng Zhou,Junzheng Wang,Rurong Zheng,Yun Gong,Jianhua Lin
Two chromite spinel-based composite materials, Mn II Cr III 2 O 4 /Mn II Mn III 2 O 4 /C and CoCr 2 O 4 /C are successfully synthesized by a solid-state conversion process via annealing Mn Cr-coordination compound and Co Cr-coordination compound at 350 °C in air for 1 h, respectively. The two composite materials both show the morphology of nanoparticles , in which the spinels are embedded in carbon matrix into a continuous phase. The as-prepared composite materials are used as supercapacitor electrodes in basic electrolyte. The Mn II Cr III 2 O 4 /Mn II Mn III 2 O 4 /C composite material possesses a high specific capacity of 184.0 mAh g −1 at a current density of 0.5 A g −1 with a superior rate capability of 138.3 mAh g −1 (75.2% retention) at 20 A g −1 . Meanwhile, CoCr 2 O 4 /C nanoparticles also deliver a high specific capacity of 158.8 mAh g −1 at a current density of 0.5 A g −1 with a superior rate capability of 125.0 mAh g −1 (78.7% retention) at 20 A g −1 . The good supercapacitive behaviors of the two composite materials are probably attributed to the characteristics of bimetallic compound and the presence of multiple valence states in the samples, giving rise to obvious redox responses. And the Mn II Cr III 2 O 4 /Mn II Mn III 2 O 4 /C and CoCr 2 O 4 /C composites possess reversible electrochromism .
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yuncheng Zhou,Yuxing Xu,Jiechen Song,Qiangqiang Tan
Mn-based cation disordered rock-salt (DRX) cathode materials exhibit promising application prospects due to their cost-effectiveness and high specific capacity. However, the synthesis methods commonly employed for these materials rely on the solid-state reaction method and mechanochemistry method, primarily attributed to the influence of low-valence states of Mn. Currently, sol–gel approaches for preparing Mn-based DRX cathode materials are limited to systems involving Mn3+. Furthermore, there is a paucity of research regarding the modification of Mn-based DRX. To address this concern, the submicrometer-sized carbon-coated Li1.2Mn0.2Ti0.6O2/C materials were synthesized via a one-step sintering process using the sol–gel method with sucrose as the carbon source, resulting in smaller particle sizes compared to those prepared by the solid-state reaction at the same temperature. When employed as a cathode material for lithium batteries, samples prepared with 10 wt % sucrose exhibited exceptional cycling stability by delivering an initial discharge specific capacity of 119.6 mA h g–1 (at a current density of 20 mA g–1). After 20 charge–discharge cycles, a reversible specific capacity of 91.0 mA h g–1 was achieved, with a capacity retention rate of 76.1%. This approach provides distinctive insights and strategies for the preparation and modification of manganese–titanium-based disordered rock-salt cathode materials.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xinyu Yang,Yueying Zhang,Xidong Hao,Yang Song,Xishuang Liang,Fengmin Liu,Fangmeng Liu,Peng Sun,Yuan Gao,Xu Yan,Geyu Lu
In this paper, an amperometric gas sensor based on proton exchange membrane (Nafion) was fabricated for H 2 S detection at room temperature . Pt-Rh nanoparticles loaded on carbon fibers, as sensing electrode , was prepared by chemical reduction method, and membrane electrode assemble (MEA) was fabricated using hot-pressing method. X-ray diffractometry (XRD) and field emission scanning electron microscopy (FESEM) were used to analyze the structure and morphology of the fabricated electrode material. The effect of the weight ratio of Pt to Rh on the performance of the sensor was investigated and the results showed that the sensing performance was best when the ratio of Pt to Rh was 1:1. Moreover, the sensitivity had been significantly improved due to the use of carbon fibers pretreated by nitric acid, increasing from 0.158 μA/ppm to 0.191 μA/ppm. The present sensor could detect H 2 S at levels as low as 0.1 ppm with a −20 nA response and had a good linear relationship in the range of 0.1 to 200 ppm H 2 S. In addition, this amperometric H 2 S sensor displayed fast response-recovery rate as well as excellent selectivity and stability.
研究领域:
材料科学
·
环境监测
·
化学传感器
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DOI
高影响因子
ADVANCED MATERIALS
·
2025
·Vol. 37
·期 34
·2507254
·
IF 26.8
Zihao Wen,Yiwen Liu,Jing Yang,Yuhui Chen,Yaming Fu,Lei Zhuang,Hulei Yu,Yanhui Chu
Achieving exceptional oxidation resistance at elevated temperatures is long desirable for ultrahigh-temperature materials to be used in relevant applications such as hypersonic flights, re-entry vehicles, and propulsion systems. However, their practical service temperatures are typically limited to below 3000 °C. Here, the exploration of (Hf, Ta, Zr, W)C high-entropy carbides with exceptional oxidation resistance of 2.7 µm·s −1 up to 3600 °C through a high-entropy compositional engineering strategy is reported. This impressive oxidation behavior arises from the formation of unique dual-structural oxide layers involving numerous high-melting-point W particles uniformly embedded within molten (Hf, Me) 6 (Ta, Me) 2 O 17 (Me = metal element, Hf, Ta, Zr, and W) primary oxides. The developed (Hf, Ta, Zr, W)C demonstrates a significant breakthrough for ultrahigh-temperature applications up to 3600 °C, paving the way for further design of advanced ultrahigh-temperature materials capable of serving at higher service temperatures.
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DOI
PubMed
高影响因子
Journal of Sulfur Chemistry
·
2026
·
IF 1.7
Laigong Guo,Yuyang Wang,Xingyu Liu,Tao Ge
The limited van der Waals force between MoS2 and the graphene substrate in MoS2/graphene heterojunctions can lead to problems such as partial aggregation of MoS2 nanosheets, uncontrollable geometric structures, and loose binding of the robust scaffold. To address these issues, this study explored a strategy of coating MoS2 with dopamine and carbonizing it under microwave-assisted conditions to optimize the lithium storage structure. The research results showed that MoS2/polydopamine mass ratio of 1:1 and microwave radiation power of 700 W were the optimal process conditions for the preparation of MoS2@C composite materials. At this point, MoS2 was completely embedded in the carbon framework, and the carbon layer provided good electrical conductivity and could suppress the structural changes of MoS2. The MoS2@C structure exhibited excellent adsorption performance for Li+, which was beneficial for the storage and transfer of Li + during charge and discharge cycles.
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DOI
高影响因子
Green Energy & Environment
·
2026
·
IF 16.7
Xiangyu Guo,Changxue Xie,Xinyao Dong,Han Xiao,Huiye Wei,Kaidi Mao,Tongan Yan,Yunpan Ying,Huina Wang,Chongli Zhong
Highly c-oriented Cu-TCPP ultrathin membrane was prepared through in-situ conversion method. • Green solvents and minimal amount of ligand were used in membrane preparation process. • The membrane can efficiently discriminate linear molecules from non-linear and non-planar molecules. • The shape-based separation mechanism was verified by DFT calculation. Efficient separation of molecules with similar molecular weights is highly demanded in chemical and pharmaceutical industries, yet still hard to achieve with traditional polymer-based membranes. Metal-organic framework (MOF) membranes, especially ultrathin two-dimensional (2D) MOF membranes, offer a good opportunity for realizing these separations. However, current 2D MOF membranes are mainly prepared through the deposition method, which can bring uncertainty to the pore channels, compromising the separation ability. This work reports the preparation of a highly c-oriented ultrathin Cu-TCPP membrane through an electrostatic-assisted in-situ oriented transformation strategy using electrostatically adsorbed copper hydroxide nanostrands as a precursor layer. The resultant membrane has explicit transport channel to be the pores of Cu-TCPP, which enables the efficient discrimination of linear molecules from non-linear and non-planar molecules with similar and even lower molecular weights. Both the experimental work and density functional theory calculations confirm the sieving effect of the Cu-TCPP membrane towards two model molecules (methyl orange and hematoxylin). This work provides a paradigm for fully utilizing the potential of MOF membranes in the precise separation of molecules with similar molecular weights. Effective nanofiltration separation of molecules with similar molecular weights based on steric shape difference is enabled by the ultrathin c-oriented Cu-TCPP membrane prepared through a green and facile electrostatic assisted in-situ conversion strategy Download: Download high-res image (321KB) Download: Download full-size image
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2026
·
IF 8.4
Changming Qu,Chao Gao,Gang Chen,Zhihu Wang,Bangkun Zou,Jiawei Wang,Yuhao Lu,Xiaozhen Liao,Yu Qiao
Silicon (Si) is a highly promising anode material for next-generation lithium-ion batteries, yet its practical electro-performance is severely hindered by massive volume changes and unstable solid electrolyte interphase (SEI) film. Herein, we introduce a simple and cost-effective strategy to address these challenges by modifying a Si-Carbon (Si-C) composite with sodium monofluorophosphate (SMFP, a low-cost and environmentally friendly additive with high ionic conductivity). During sintering at 650°C (above the melting point of SMFP, 625°C), the melted SMFP diffuses into the Si-C particles and coats on the surface, thus could not only suppress the side reactions between Si and electrolyte but also behave as an artificial SEI film to diminish the consumption of electrolyte and Li-ions for improving initial Coulombic efficiency (ICE). The optimized SMFP-modified anode (Si-C@0.5SMFP) demonstrates significantly enhanced electrochemical performance, delivering an ICE of 84.08% and retaining a capacity of 450.7 mAh g −1 after 500 cycles at 2 A g −1 , substantially outperforming the pristine Si-C. Mechanistic investigations reveal that the superficial SMFP could protect the Si-C anode from continuous electrolyte decomposition and boost Li-ion diffusion kinetics. This work presents a scalable and economical approach to stabilize Si-based anodes, offering a promising pathway for developing the lithium-ion batteries with high-energy-density.
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）