JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Shengxin Chen,Yingwei Li,Zicheng Wang,Ying Jin,Ruixia Liu,Xingang Li
Hollow structure nanoreactors take advantage of catalyst loading and enhanced activity by shell construction. In this work, functionalized poly(ionic liquid)s (PILs) with hollow spherical structures were synthesized by polymerization- and quaternization-based approaches. These hollow structure PILs (HPILs) could be controllable designed from IL monomer easily, giving HPILs various properties. In the subsequent selective oxidation of cyclohexane , the HPILs acting as nanoreactors could efficiently improve the activity of metal salt catalysts (CoCl 2 ) and displayed adjustable selectivity for cyclohexanone, cyclohexanol (KA) or adipic acid (AA) by different types of HPILs. In kinetic study , it follows first-order reaction kinetics which CoCl 2 /HPIL-C12 had a lower the activation energy of 29.1 kJ/mol. Importantly, these nanoreactors storing the catalysts could be recovered and reused more than 7 times without significant loss of activity. A theoretical model for the hollow spherical reactor was further established to support the advance of the HPILs reactor, which could also help to predict reaction process in other core-shell catalytic system. Due to controlled substrate transfer and enhanced radical generation in HPILs, the reaction process could be adjusted to enhance the conversion of cyclohexane and selective oxidation to AA.
研究领域:
化学工程
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
ACS Applied Polymer Materials
·
2021
·
IF 4.089
Chunying Min,Yuzi Yang,Hongyu Liang,Zengbao He,Qiuying Li,Jinfeng Zhu,Kan Zhang,Haiting Shi,Wei Wang
The isomeric poly(hexahydrotriazine)s (PHTs) were prepared, based on their hemiaminal dynamic covalent networks via a facile method at 50 °C, through 1,3-bis(4-aminophenoxy)-benzene (TPE-R) and 1,4-bis(4-aminophenoxy)-benzene (TPE-Q) with formaldehyde. The influence of chain isomerism on thermal stability, mechanical properties, tribological properties, and the degradation rate of PHTs was investigated. The advantage of (TPE-Q)-PHTs compared with that of (TPE-R)-PHTs is that they possessed a higher glass transition temperature (Tg) of 187 °C, a higher Yang’s modulus of 10.7 GPa, and rapid degradation rate. Additionally, the (TPE-Q)-PHTs exhibited outstanding self-lubricating performance as compared to (TPE-Q)-PHTs because the para-connecting isomers showed lower surface energy, lower surface roughness, and higher hardness that effectively weakened the bonding force between friction pairs. Overall, the study of PHTs facilitates their practical application of energy conservation and environmental protection in the tribological industry.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Tiancheng Na,Yang Liu,Xiangcun Li,Wenji Zheng,Yan Dai,Zhijun Yan,Wei Kou,Gaohong He
We report a method based on 2,4-dihydroxybenzoic acid-formaldehyde (RF-COOH) microsphere hard templates to prepare core-shelled Fe 2 O 3 microspheres , which were then added to graphene oxide to obtain hierarchical reduced graphene oxide, ultimately dropping Fe 2 O 3 (Fe 2 O 3 @rGO) by Vitamin C reduction and freeze drying. When used as cathode materials for lithium-sulfur batteries, Fe 2 O 3 @rGO shows a high specific capacity of 400.5 mAh g −1 at 2 C after 500 cycles. The prominent performance is due to the collaborative assembly of rGO , which provides stable structural support and favourable conductivity, and core-shelled Fe 2 O 3 microspheres, which are certified to have a strong interaction with polysulfides. The loose and stable skeletons of highly electroconductive rGO can offer a conductive framework for rapid ion/electron transport. Meanwhile, the unique core-shelled structure of Fe 2 O 3 with the ample void space can anchor polysulfides through the strong chemical adsorption and buffer the mechanical stresses caused by volume expansion during the charge and discharge processes. Moreover, Fe 2 O 3 promotes the transformation of polysulfides to insoluble LiPSs during the discharging process, effectively alleviating the shuttling of the polysulfides.
研究领域:
材料科学
·
能源存储
·
电化学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2026
·
IF 5.2
Mingsheng Liu,Lian He,Shuanjin Wang,Dongmei Han,Sheng Huang,Min Xiao,Yuezhong Meng
Polythiocarbonates (PTCs) represent a class of polymers derived from polycarbonates. While numerous synthetic methodologies have been reported, their practical applications remain unexplored. This study employs a one-pot bulk polymerization approach using propylene oxide (PO) and carbon disulfide (CS2) to synthesize polythiocarbonates, systematically investigating the effects of reaction temperature and duration on polymer properties. Results demonstrate that optimized reaction conditions fail to suppress O/S exchange, inevitably yielding polymers containing diverse thiocarbonate groups with varying stabilities. Consequently, we established the structural thermal stability hierarchy of thiocarbonate linkages: S(C═O)O > S(C═O)S > O(C═S)O > S(C═S)S > S(C═S)O. Density functional theory (DFT) calculations of bond dissociation energies (BDEs) corroborate this experimentally determined sequence. Our findings identify inherent structural instability as the fundamental barrier to polythiocarbonate applications, providing critical design principles for developing functionally stable PTCs.
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 11
·114504
·
IF 4.316
Yinling Wang,Nannan Ma,Mingli Fan,Wujian Tang
Transition metal phosphides (TMP) are excellent non-precious metal electrocatalysts for hydrogen evolution reaction (HER). The generation of PO43− before and during the HER process may be inevitable due to the instability of TMP. To investigate the effect of PO43− on the HER catalytic activity of electrocatalysts in alkaline medium, NiCo-S nanotubes were modified with phytate (PHY) with six phosphate groups via adsorption. The successful modification was verified by zeta potential, FT-IR, element mapping, XPS, etc The NiCo-S/PHY displayed a higher HER activity than original NiCo-S. Under the optimum adsorption time (7 h), the overpotential at 10 mA cm−2 (η10) of NiCo-S/PHY (173 mV) was only half that of the original NiCo-S (346 mV). The role of PO43− was discussed in detail. Moreover, this strategy was extended to NiCo-S grown directly on nickel foam (NiCo-S/NF) and the corresponding NiCo-S/PHY/NF also showed superior HER activity and good stability. This work provides a new strategy to improve the HER activity of electrocatalysts and also a novel perspective for the HER mechanism of TMP.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Binbin Zhang,Ruichao Lu,Yueli Cheng,Kamran Amin,Lijuan Mao,Zhixiang Wei
Drastic capacity decay as a result of active sulfur loss caused by the severe shuttle effect of dissolved polysulfides is the main obstacle in the commercial application of Li–S batteries. Various methods have been developed to suppress the active sulfur loss, but the results are far from ideal. Herein, we propose a facile sulfur compensation strategy to improve the cyclic stability of Li–S batteries. The strategy is to compensate sulfur to the cathode by chemical reactions between additional sulfur and lithium polysulfides diffusing away from the cathode. The compensatory sulfur can effectively mitigate the loss of active sulfur in the cathode side caused by the shuttle effect and thus maintain the high capacity of the battery during charging and discharging for long life cycle assessments. Using this strategy, the specific capacity of the assembled Li–S batteries was maintained at >700 mA h g–1 for more than 500 cycles at 1 C and >1000 mA h g–1 for ∼100 cycles at 0.1 C, while the capacity of control batteries rapidly decreased to <200 mA h g–1 under the same conditions.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2015
·
IF 4.529
Lianqin Zhao,Baowei Yu,Fumin Xue,Jingru Xie,Xiaoliang Zhang,Ruihan Wu,Ruijue Wang,Zhiyan Hu,Sheng-Tao Yang,Jianbin Luo
Graphene sponge (GS) has been widely employed for water purification, but adsorption capacity loss frequently occurs during the formation of spongy structure. In this study, we reported the hydrothermal preparation of S-doped GS for the removal of Cu 2+ with a huge adsorption capacity of 228 mg/g, 40 times higher than that of active carbon. The adsorption isotherm could be well fitted into the Freundlich model with a K F value of 36.309 (L/mg) 1/ n . The equilibrium adsorption could be fully achieved in the first 5 min. In the thermodynamics study, the negative Δ G indicated that the adsorption was spontaneous and physisorption in nature. The positive Δ H implied that the adsorption was endothermic. The changes of both pH and ionic strength had no apparent influence on the adsorption. S-doped GS could be easily regenerated by washing with acidic thiourea. Moreover, S-doped GS could be used for the adsorption of other heavy metal ions, too. The implication to the applications of S-doped GS in water treatment is discussed.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Cai Qi,Shu Zu,Xukun Zhu,Tong Zhang,Longyan Li,Li Song,Yachao Jin,Mingdao Zhang
Functional and active carbon material is of great concern in facilitating the performance of lithium-sulfur (Li-S) battery . In this work, we develop a bamboo-like nitrogen-doped carbon nanotubes (Co@NCNTs-2) with low cobalt metal content, which acts as not only the host matrix for sulfur loading but also an efficient catalyst for the adsorption and conversion of lithium polysulfides (LiPSs). The characterization results show that the Co particles are mainly encapsulated inside the Co@NCNTs-2, and the N species are mainly distributed on the outer surface of Co@NCNTs-2. The Co particles are the growth sites of carbon nanotubes and are wrapped by carbon to form Co@NCNTs-2. It is confirmed that the uniform graphitized structure contributes to charge transfer, while the enriched N species assist the trap and catalytic conversion of the polysulfides, thus helping to restrain the shuttle effect. As a result, the resultant Co@NCNTs-2-S cathode presents high reversible capacity at different current densities and exhibits superior cycling stability for 300 cycles at 0.5 C.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
DESIGNED MONOMERS AND POLYMERS
·
2017
·
IF 1.139
Yuxuan Zhang,Shuang Wang,Zhonghui Wang,Saisai Gai,Xi-Ming Song
A series of novel poly(arylene ether)s with crosslinked groups and different azobenzene chromophores contents (azo-CPAEs: PAE-allyl20%-azo20%, PAE-allyl20%-azo40%, PAE-allyl20%-azo60%) were synthesized from a new bisfluoro monomer, (2,6-difluorophenyl)-(4-hydroxyphenyl)methanone. Their chemical structures were characterized by means of UV-vis and FI-IR. The thermal properties of the polymers were investigated by TGA and DSC, indicating the polymers had high glass transition temperatures (Tg > 147 °C) and good thermal stability (Td5 > 360 °C) even when the contents of azobenzene chromophores was high to 60%. And the influence of thermal crosslinking on the performance of PAE-allyl20%-azo20%, a typical one of the series, was investigated. Tg of PAE-allyl20%-azo20% increased with the increase of heating time when heat-treated at 250 °C for 20, 40 and 60 min, indicating the crosslink degree of the polymer increased. After heat-treated for 60 min, Tg of PAE-allyl20%-azo20% increased to 175 °C from 147 °C before thermal crosslinking. Upon irradiation with a 532 nm neodymium doped yttrium aluminum garnet (Nd:YAG) laser beam, the remnant value of the polymer PAE-allyl20%-azo20% before and after the thermal crosslinking were 81 and 96%, respectively, meaning that the PAE-allyl20%-azo20% after thermal crosslink showed more stable photoinduced alignment than that before thermal crosslinking.
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 21
·3770
·
IF 5.719
Ruowei Yi,Yinchao Zhao,Chenguang Liu,Yi Sun,Chun Zhao,Yinqing Li,Li Yang,Cezhou Zhao
The nitrogen-doped MXene carbon nanosheet-nickel (N-M@CNi) powder was successfully prepared by a combined process of electrostatic attraction and annealing strategy, and then applied as the separator coating in lithium–sulfur batteries. The morphology and structure of the N-M@CNi were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectrum, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption method. The strong LiPS adsorption ability and high conductivity are associated with the N-doped carbon nanosheet-Ni modified surface. The modified separator offers the cathode of Li–S cell with greater sulfur utilization, better high-rate adaptability, and more stable cycling performance compared with the pristine separator. At 0.2 C the cell with N-M@CNi separator delivers an initial capacity of 1309 mAh g−1. More importantly, the N-M@CNi separator is able to handle a cathode with 3.18 mg cm−2sulfur loading, delivering a capacity decay rate of 0.043% with a high capacity retention of 95.8%. Therefore, this work may provide a feasible approach to separator modification materials towards improved Li-S cells with improved stability.Keywords:MXene;carbon nanosheets;lithium–sulfur batteries;modified separator
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产品关联
DOI
PubMed
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 40
·e202203024
·
IF 2.307
Xuehui You,Fang Liu,Guofei Jiang,Shuhua Chen,Beiya An,Rongli Cui
Graphical Degradation experiments of TC suggested that SCN/NT-2@PTFE composites showed the best photocatalytic performance under the optimal conditions, the degradation rate of tetracycline reached 99 % after 120 min of irradiation. The preparation of SCN/NT-2@PTFE composite membrane can solve the problem of difficult recovery and secondary contamination of powder catalysts. Herein we synthesized S-g-C 3 N 4 and N−TiO 2 catalysts by hydrothermal and calcination technologies and SCN/NT@PTFE membrane by a vacuum filtration method. The morphology and composition of the synthesized materials were analyzed by different characterization methods (SEM/HRTEM/XRD/XPS/UV-vis et.). The effects of different catalysts, pollutant concentrations, mass of catalyst and pH on the photo-degradation of tetracycline were investigated. The degradation rate of tetracycline by SCN/NT-2@PTFE membrane was as high as 99.9 % after 2 h of illumination. This was mainly because heterogeneous structure between S-g-C 3 N 4 and N−TiO 2 broadened the light absorption range and suppressed the carrier complex. Superoxide radicals (⋅O 2 − ) were proved to play a dominant role in the degradation reaction. After 20 days of stirring in water, the photocatalytic performance of membrane decreased slightly, demonstrating its good stability. The study of SCN/NT-2@PTFE membrane provides a new direction for the development of photocatalysis and membrane.
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2023
·
IF 5.8
Qiang Huang,Zhiren Zou,Xiaobo Li,Qinwen Xiao,Guang Liang,Wenqi Wu
The drug-amino acid co-amorphous systems and amorphous solid dispersions (ASDs) are promising methods to address the poor water solubility of poorly water-soluble drugs. However, some amino acids might not be perfect co-formers for co-amorphous systems, and the relatively low drug-loading of many ASDs is one of the main disadvantages of ASDs. Thus, poly- l -lysine and polyglutamic acid were selected as the co-formers, ball milled with basic mebendazole, neutral tadalafil and acidic valsartan at different weight ratios (from 3:1 to 1:3) to prepare poly (amino acid)-based ASDs, aiming to combine the advantages of co-amorphous systems (high drug-loading) and ASDs (relatively high T g and high physical stability). All the mixtures were converted into amorphous after milling. The powder dissolution studies showed that drug-poly (amino acid) ASDs improved the dissolution rate of the drug in different ways and to different degrees. Moreover, the two poly (amino acid)s enhanced the physical stability of amorphous drugs. It is worthy to mention that the salt formation between the drug and the poly (amino acid) does not necessarily mean better performance compared to non-salt forming systems, and salt formation is also not a prerequisite for the formation of promising drug-poly (amino acid) ASDs.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）