Journal of Advanced Ceramics
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2022
·Vol. 11
·期 9
·1491-1497
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IF 11.534
Liu Yi,Wang Chuangye,Luo Wei,Bai Liang,Xu Yang,Hao Xiaodong,Zhu Jianfeng,Guo Shouwu
The microstructure and morphology of Ti 3 AlC 2 powders not only affect the preparation of Ti 3 C 2 MXene but also have a great influence on their potential applications, such as microwave absorbers, alloy additives, or catalytic supports. However, the synthesis of Ti 3 AlC 2 powders with desired microstructure and morphology remains a challenge. Herein, hollow Ti 3 AlC 2 microrods were prepared for the first time in NaCl/KCl molten salts by using titanium, aluminum, and short carbon fibers as starting materials. It was found that the short carbon fibers not only performed as carbon source but also acted as sacrificial template. Furthermore, it was revealed that TiC and Ti 2 AlC were initially formed on the surface of carbon fibers. The subsequent reactions between the outer Ti, Al and the inner carbon were dominated by the Kirkendall effect which gave rise to the formation of a hollow structure. Based on this mechanism, hollow Ti 3 AlC 2 microspheres and a series of hollow TiC, Ti 2 AlC, and V 2 AlC powders were also successfully fabricated. This work provides a facile route to synthesize hollow MAX phases and may give enlightenment on preparing other hollow carbide powders via the Kirkendall effect in the molten salts.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
·
IF 13.2
Lv Xi,Xu Xincheng,Peng Yang,Li Bolin,Yang Lie,He Xiaoman
This study introduces a novel modification method for micron-sized zero-valent iron, utilizing Shewanella oneidensis MR-1 to simultaneously colonize its surface, disrupt the passivation layer, and alter the crystal structure of the core. This process yields a composite that retains its reducing activity even in high concentrations of pollutants (500 ppm Cr(VI)) and under neutral to slightly acidic conditions. Our findings indicate that the modified system induces the Kirkendall effect in zero-valent iron, leading to the formation of amorphous zero-valent iron with a non-spherical core structure, in contrast to conventional direct mixing approaches. The modified system achieves complete reduction of 100 ppm Cr(VI) to Cr(III) within 8 h. Notably, within the first 4 h of reaction, the reduction rate is approximately three times higher than that of the conventional direct mixing system. XPS, XRD, SEM, EEM and TEM analyses reveal that the surface passivation layer of the biochemically modified zero-valent iron is disrupted, leading to changes in its crystal structure, the formation of hollow spherical structures, and the development of a biological protective film on its surface. Interestingly, electrochemical and ETSA analyses indicate that the electron transfer rate of the biochemically modified composite is significantly enhanced. This study provides fundamental insights into the removal of Cr(VI) from groundwater using biochemically modified micron-sized zero-valent iron (mZVI).
研究领域:
环境科学
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微生物学
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DOI
高影响因子
Advanced Energy Materials
·
2018
·Vol. 9
·期 1
·1803035
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IF 21.875
Peng Ge,Sijie Li,Laiqiang Xu,Kangyu Zou,Xu Gao,Xiaoyu Cao,Guoqiang Zou,Hongshuai Hou,Xiaobo Ji
As a result of its high-energy density, metal–selenides have demanded attention as a potential energy-storage material. But they suffer from volume expansion, dissolved poly-selenides and sluggish kinetics. Herein, utilizing' thermal selenization via the Kirkendall effect, microspheres of NiSe 2 confined by carbon are successfully obtained from the self-assembly of Ni-precursor/PPy. The derived hierarchical hollow architecture increases the active defects for sodium storage, while the existing double N-doped carbon layers significantly alleviate the volume swelling. As a result, it shows ultrafast rate capability, delivering a stable capacity of 374 mAh g −1 , even after 3000 loops at 10.0 A g −1 . These remarkable results may be ascribed to the Ni O C bonds on the interface of NiSe 2 and the carbon film, which leads to the faster transfer of ions, the effective trapping of poly-selenide, and the highly reversible conversion reaction. The kinetic analysis of cyclic voltammetry (CV) demonstrates that the electrochemical process is mainly dominated by pseudocapacitive behaviors. Supported by the results of electrochemical impedance spectroscopy (EIS), it is confirmed that the solid–electrolyte interface films are reversibly formed/decomposed during cycling. Given this, this elaborate work might open up a potential avenue for the rational design of metal-sulfur/selenide anodes for advanced battery systems.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
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2023
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IF 4.6
Weizuo Li,Jing Shi,Dafang He,Haiqun Chen
Catalysts with an open hollow structure can enhance the mass transfer capability of the catalyst during the reaction process, thereby further improving the catalytic performance. In this work, uniform and monodisperse flying-squircher-shaped Al-MOFs were synthesized via a solvothermal method. Furthermore, a hollow structure Al2O3-supported metallic Ni catalyst (termed Ni–Al2O3–HFA) was synthesized via the Kirkendall effect for the hydrogenation–alkylation cascade reaction by employing as-synthesized Al-MOFs as a carrier for impregnation of Ni(NO3)2·6H2O through further calcination and reduction. Various characterizations (e.g., XRD, HADDF-STEM, H2-TPR) were conducted to reveal the superior performance of the developed Ni–Al2O3–HFA catalyst compared to Ni/Al2O3–IWI (Al2O3 obtained from calcination of Al-MOFs) in cascade reaction between nitroarenes and alcohols. We hope to use the MOF template method via the Kirkendall effect to prepare hollow structure nanocatalysts, which can provide a guideline for the preparation of other hollow materials.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Yiming Guo,Jun Sun,Yongxing Lin,Xiangyang Li,Gang Liu,Yi Gong,Xian Zhang,Xingyou Tian,Xiaoxiao Li,Lin Chen
The precise modulation of morphology engineering utilizing metal-organic frameworks (MOFs) presents a promising avenue for the development of optimal microwave absorbers. Nonetheless, challenges emerge due to the tendency of MOF derivatives to either collapse or exist in isolation, which can impede the dissipation of electromagnetic waves (EMWs) and diminish their efficacy as microwave absorbers. Herein, this work proposes a pragmatic strategy for modulating the dielectric properties of MOF derivatives through the incorporation of Fe. By introducing Fe 3+ into the ZIF-67-on-ZIF-8 precursor, and leveraging the Kirkendall effect, a CoFe@hollow carbon nanocage (HCN) structure with a large opening is synthesized post-pyrolysis. This structure effectively addresses the issues related to the contact between MOF derivatives and their inadequate conductivity, resulting in remarkable microwave absorption (MA) performance at a low paraffin filling ratio of 15 wt%. The amount of Fe doping allows for flexible control over the dielectric properties, which are influenced by morphological evolution and the extent of graphitization, leading to tunable MA characteristics. Consequently, exceptional MA performance is achieved, characterized by both broad bandwidth absorption (6.3 GHz) and high-efficiency loss (-60.09 dB). This research elucidates an intrinsic mechanism linking microtopology to MA properties, offering significant insights that are anticipated to guide the future development of dielectric MA materials through morphology engineering methodologies.
研究领域:
材料科学
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电磁学
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产品关联
DOI
高影响因子
Scientific Reports
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2014
·Vol. 4
·期 1
·1-6
·
IF 5.078
Han Lin,Liu Hui,Cui Penglei,Peng Zhijian,Zhang Suojiang,Yang Jun
Noble metal nanoparticles with hollow interiors and customizable shell compositions have immense potential for catalysis. Herein, we present an unique structure transformation phenomenon for the fabrication of alloy Cu 3 Pt nanoframes with polyhedral morphology. This strategy starts with the preparation of polyhedral Cu-Pt nanoparticles with a core-shell construction upon the anisotropic growth of Pt on multiply twinned Cu seed particles, which are subsequently transformed into alloy Cu 3 Pt nanoframes due to the Kirkendall effect between the Cu core and Pt shell. The as-prepared alloy Cu 3 Pt nanoframes possess the rhombic dodecahedral morphology of their core-shell parents after the structural evolution. In particular, the resulting alloy Cu 3 Pt nanoframes are more effective for oxygen reduction reaction but ineffective for methanol oxidation reaction in comparison with their original Cu-Pt core-shell precursors.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2017
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IF 6.065
Sheng Luo,Fan Qin,Yin’an Ming,Huiping Zhao,Yunling Liu,Rong Chen
Hazardous hexavalent chromium removal from wastewater is an urgent issue in industry environmental pollution. In this work, hollow Bi 2 S 3 nanospheres have been successfully synthesized from unique Bi 2 O 3 porous nanospheres via Kirkendall effect through hydrothermal process. It was found that the sulfur source and the initial Bi 2 O 3 templates played key roles in the formation of the uniform morphologies and structures through an anion exchange process. Compared with other Bi 2 S 3 samples, the synthesized hollow Bi 2 S 3 nanospheres exhibited much enhanced photocatalytic ability for Cr(VI) photoreduction. XPS analysis demonstrated that Cr(VI) was reduced to less harmful Cr(III) species over hollow Bi 2 S 3 nanospheres under visible-light irradiation. More importantly, the hollow Bi 2 S 3 nanospheres remained high efficiency and good stability in the recycling Cr(VI) photoreduction, and exhibited remarkable Cr(VI) removal ability in actual electroplating industry wastewater treatment.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2012
·Vol. 14
·期 19
·6295-6305
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IF 3.842
Wei Chen,Hong Ruan,Yin Hu,Danzhen Li,Zhixin Chen,Jiangjun Xian,Jing Chen,Xianzhi Fu,Yu Shao,Yi Zheng
We report here a facile one-step strategy to prepare hollow ZnO core/ZnS shell structures by microwave irradiation. The growth mechanism of the hollow core/shell structures was investigated in detail. ZnO truncated hexagonal pyramids first form on as-grown precursor flakes and then evolve into ZnO hexagonal twin crystals, which subsequently grow up and dissolve internally. The hollowing progress is firstly controlled by the Kirkendall effect and then undergoes an Ostwald ripening process. Hollow structures and the formation of ZnO/ZnS heterostructure bring enhanced photocatalytic activities to ZnO core/ZnS shell structures. The formed ZnO/ZnS heterostructures also fill the surface defects of ZnO crystals and improve the stability of the photocatalysts by overcoming the photocorrosion effect of a single ZnO photocatalyst under UV light irradiation. Superoxide radicals (O˙−2) are the key active species in the photocatalytic system of degradation of p-chlorophenol over hollow ZnO core/ZnS shell structures. The photocatalysis process has been discussed and a possible mechanism also has been proposed. This work is helpful to controllably construct other hollow core/shell structures, develop ZnO-based photocatalysts without photocorrosion effect and further study the photocatalytic mechanism of similar systems.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2020
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IF 4.65
Yuzhe Wu,Qipeng Cai,Yuntong Li,Huixiang Liu,Jie Mao,Zhenwu Lu,Birong Zeng,Yiting Xu,Conghui Yuan,Lizong Dai
Incorporation of two or more types of metallic atoms into carbon matrix is of particular interest in the fabrication of high performance electrode materials. This normally requires complex synthetic routes or intricate post-processing process. Moreover, the composition and morphology of the resultant carbon materials are uncontrollable. Herein, we show the first time that a bimetal ions (Sn 4+ and Fe 3+ ) etching method based on Kirkendall effect can transform boronate polymer assemblies into metallosupramolecular polymer hollow spheres, which can be carbonized into carbon shells comprising FeSn 2 alloy. The carbon shells display evidently improved activity towards oxygen reduction reaction with onset potential 0.94 V and half-wave potential 0.84 V vs. RHE, which are comparable to that of Pt/C. The as formed FeSn 2 alloy in the carbon matrix possesses characteristics of rich in electrons, excellent conductivity and high chemical activity. Our supramolecular approach is simple, and able to control both the composition and morphology of the carbon materials, which may afford a new strategy for the design of higher performance electrochemical catalysts.
研究领域:
材料科学
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电化学
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 16
·13371-13376
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IF 3.289
Yunshi Liu,Ping Yang,Jia Li,Katarzyna Matras-Postolek,Yunlong Yue,Baibiao Huang
SiO2@SnO2 core–shell nanofibers (NFs) were successfully prepared by single-spinneret electrospinning and subsequent calcination process. The precursor solutions were prepared from poly(vinylpyrrolidone), SnO2 precursors, and tetraethylorthosilicate (TEOS) with prehydrolysis. The prehydrolysis of TEOS plays an important role for the formation of core–shell structure. After calcining, the resulting fiber sample had an amorphous SiO2 core and a shell consisted of SnO2 particles. The fibers with various morphologies were obtained through adjusting the molar ratio of Sn and Si and the possible formation mechanism of core–shell NFs was proposed. Both Kirkendall effect and grain growth played important roles for the formation of core–shell structure. Furthermore, SiO2 was used as support material to fix the SnO2 particles and avoid the collapse of the SnO2 structure. The amount of SnO2 precursors directly determined the compactness of the shell, resulting in the different gas sensing properties. The SiO2@SnO2 core–shell NF network sensor responds to ethanol, ammonia, benzene, toluene, chloroform, and hexane gases, but it exhibited enhanced gas response to ethanol with a short response time. Those SnO2 particles formed on the exterior of the fibers provided lots of contact area with the target gas to reduce resistance. In addition, the connectivity between particles also had certain influence on the electrical conductivity of the sample. The results demonstrate that single-spinneret electrospinning can also be used to prepare core–shell fibers with various applications.
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
·
IF 7.489
Chunhui Wang,Bao Zhang,Xing Ou,Haifeng Xia,Liang Cao,Lei Ming,Jiafeng Zhang
Structure control is widely admitted as a feasible strategy to restrain volume change and enhance electrical conductivity for chalcogenide anode materials . Herein, three-dimensionally hierarchical structure Co 0.85 Se@N-doped graphene hybrid is well-designed and synthesized by a facile hydrothermal strategy and post-calcination. It is noted that, owing to the nanoscale Kirkendall effect, the Co 0.85 Se nanograins derived from uniform zeolitic imidazolate framework (ZIF-67) precursor are incorporated into a polyhedron-in-polyhedron structure, which is consisted of in-situ formed amorphous carbon and interconnected pliable graphene nanosheets with enormous N-doping atoms. This unique dual-carbon protecting layers are beneficial to mitigate the volume expansion with high integrity, and facilitate the fast Li/electron transport with improved conductivity simultaneously, thus resulting in the superior Li-storage performance. As expected, the framework-controlled Co 0.85 Se@N-doped rGO composite demonstrates an outstanding cycling stability (787.7 mA h g −1 after 1000 cycles at 2 A g −1 ) and remarkable rate capability (400.8 mA h g −1 at ultrahigh rate of 10 A g −1 ). This work presents an enlightened strategy to design chalcogenide anode with desired nano-/microstructure by structure control and kinetic increase.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Ximin Ling,Wutao Wei,Changwei Shan,Xuyan Qin,Mingjie Song,Zhao Liu,Liwei Mi
Mg 2+ /Li + hybrid batteries (MLHBs), which support the rapid insertion and removal of Mg 2+ /Li + bimetallic ions, are promising energy storage systems. Inspired by the Kirkendall effect, ball-in-ball bimetallic sulfides with heterostructures were prepared as cathode materials for the MLHBs. First, a nickel–cobalt precursor (NiCo-X precursor) with three-dimensional (3D) nanosheets on its surface was prepared using a solvothermal method based on the association reaction between alkoxide molecules. Subsequently, the NiCo-X precursor was vulcanized at high temperature using the potential energy difference as the driving force to successfully prepare NiS 2 @CoS 2 core–shell hollow spheres. When used as the positive electrode material for the MLHBs, the NiS 2 @CoS 2 hollow spheres exhibited excellent Mg 2+ /Li + ion storage capacity, high specific capacity, good rate performance, and stable cyclic stability owing to their tough hierarchical structure. At a current density of 500 mA g −1 , a specific capacity of 536 mAh g −1 was maintained after 200 cycles. By explaining the transformation mechanism of Mg 2+ /Li + in bimetallic sulfides, it was proven that Mg 2+ and Li + worked cooperatively. This study provides a new approach for developing MLHBs with good electrochemical properties.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）