JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Yuxiao Jia,Xuancheng Wang,Leijie Hu,Xuezhang Xiao,Shuoqing Zhang,Jiahuan He,Jiacheng Qi,Ling Lv,Fen Xu,Lixian Sun,Lixin Chen
Ultrafine carbon-based transition metal compounds have been widely investigated as efficient catalysts for enhancing the hydrogen storage performance of magnesium hydride. In this work, the carbon thermal shock method is applied to synthesize the ultrafine carbon-encapsulated NbC nanoparticles with an average grain size of 17.3 nm. The MgH 2 –10 wt% NbC/C composites show excellent low-temperature hydrogen storage performance with the onset dehydrogenation temperature of 196.1 °C, which is 92.2 °C and 98 °C lower than that of MgH 2 –10 wt% NbC and undoped MgH 2 , respectively. Specifically, MgH 2 –10 wt% NbC/C can absorb 6.71 wt% H 2 at 100 °C within 30 min around and retain almost 100% reversible hydrogen desorption capacity after 10 cycles. For the catalytic mechanism, the electron transfer process between multi-valence Nb cations of in-situ formed NbH x and Mg, H atoms can greatly improve the cyclic de/rehydrogenation kinetics of MgH 2 -NbC/C. Besides, the enhancement of dehydrogenation kinetics can also be ascribed to MgH 2 particle refinement by NbC nanoparticles, and destabilization of the Mg-H bond caused by carbon substrate. This investigation not only proves that carbon-encapsulated NbC nanoparticles can greatly enhance the hydrogen storage performance of MgH 2 but provides an idea of preparing carbon-based transition metal carbides as effective catalysts for magnesium-based hydrogen storage materials.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 7
·10265-10272
·
IF 5.532
Wenchao Xi,Boxue Song,Zhengyu Sun,Tianbiao Yu,Jun Wang,Qi Sun
To improve the wear resistance of Fe-based cladding, NbC particles with different morphology are generated in situ by adding Nb, Cr 3 C 2 and C with different content. The composition of samples and the morphology of NbC particles generated in situ are revealed by XRD , SEM and EDS. The wear resistance is studied by a reciprocating friction and wear testing machine. The wear mode and the wear mechanism of each sample are investigated. The results show that although NbC particles are generated in situ in samples with different Nb, Cr 3 C 2 and C content, the morphology of NbC particles is varied. The wear resistance of samples containing cross-shaped NbC particles is more outstanding than that of samples containing only rectangular NbC particles. In addition, changing Nb, Cr 3 C 2 and C content does not result in a change in wear mode, but leads to the formation of continuous lattice structure of Cr 0.19 Fe 0.7 Ni 0.11 and Cr 23 C 6 compounds at grain boundaries and a change in the wear resistance. When the additions of Nb, Cr 3 C 2 and C are 11.2 wt%, 8.6 wt% and 0.2 wt% respectively, the coefficient of friction of the sample is the lowest, and the wear resistance is the most outstanding.
研究领域:
材料科学
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金属学与热处理
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表面工程
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摩擦学
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复合材料
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Haizhen Liu,Liwen Lu,Hui Luo,Jiayi Deng,Guangxu Li,Hua Ning,Yi Fan,Cunke Huang,Zhiqiang Lan,Wenzheng Zhou,Jin Guo,Xinhua Wang
The Li-Mg-B-H composite (2LiBH 4 + MgH 2 ) is acknowledged as a promising material for hydrogen storage due to its large hydrogen capacity (11.4 wt.%). However, the sluggish kinetics and poor reversibility make it difficult to be practically used. In this work, the hydrogen storage performances of 2LiBH 4 + MgH 2 have been significantly improved by a hybrid of bulk NbC and layered Nb 4 C 3 MXene (denoted as “Nb-C”). The 2LiBH 4 + MgH 2 + 6 wt.% Nb-C can release 8.5 wt.% H 2 within 30 min at 400°C and the dehydrogenated composite can absorb 9.3 wt.% H 2 within 30 min at 350°C and 7.5 MPa H 2 . The reversible dehydrogenation capacity maintains at 8.4 wt.% after 24 cycles, with a capacity retention ratio of 95.4%. By contrast, the undoped 2LiBH 4 + MgH 2 suffers from serious capacity degradation, with the capacity decreased dramatically to 3.5 wt.% after 3 cycles. Microstructural studies revealed that the doped composite has uniform particle and elemental distributions and possesses various multiphase interfaces of LiH/MgB 2 /NbC/Nb 4 C 3 , which is beneficial to hydrogen diffusion during the hydrogen uptake and release process. Theoretical studies by first principle calculation presented an extended bond length of the Mg-H and B-H bonds in the 2LiBH 4 + MgH 2 + NbC system, which may also explain the improved hydrogen storage properties of 2LiBH 4 + MgH 2 by addition of Nb-C. This work provides new insights into the role of transition metal carbides in regulating the Li-Mg-B-H hydrogen storage materials both experimentally and theoretically.
研究领域:
材料科学
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理论计算
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产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 2
·1090-1102
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IF 2.328
Fen Li,Hanzi Du,Ting Chen,Qikun Zhu,Zhaoju Yu
For the first time, the present work reports the dielectric properties and electromagnetic wave (EMW) absorbing performance of polymer-derived carbon-rich NbC-SiC-C nanocomposites. In our previous work, NbC-SiC-C nanocomposites with the ultra-high temperature ceramic phase NbC as the main phase were synthesized with the allylhydridopolycarbosilane (AHPCS) and niobium pentachloride (NbCl 5 ) as starting materials. On this basis, divinyl benzene was chosen as carbon-rich source and introduced into the AHPCS and NbCl 5 to form a single-source-precursor. Finally, carbon-rich NbC-SiC-C nanocomposites were successfully synthesized by polymer-derived ceramic approach. Compared with ceramic samples without Nb and with lower carbon content, the carbon-rich NbC-SiC-C nanocomposites show extremely enhanced EMW absorbing performance with minimum reflection coefficient of −51.1 dB at 6.88 GHz for the thickness of 2.27 mm. As a consequence, the resultant carbon-rich NbC-SiC-C nanocomposite has to be considered as structure&function integrated material with excellent EMW absorption performance, which can be applied in hostile environment.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 38
·21867-21876
·
IF 12.732
Zhaoxia Cao,Jian Guo,Shengnan Chen,Zhennan Zhang,Zhenpu Shi,Yanhong Yin,Mingguo Yang,Xiaoxu Wang,Shuting Yang
Lithium–sulfur (Li–S) batteries are one of the most promising next-generation energy storage systems. Nevertheless, the notorious lithium polysulfide (LiPS) shuttle and sluggish sulfur redox kinetics result in inferior electrochemical performances, which are the major obstacles to their commercial application. Engineering the surface/interface of the ultrafine polysulfide promotor which can accelerate LiPS conversion and improve sulfur utilization is still challenging. Herein, we propose an effective strategy to synthesize ultrafine heterostructural Nb2O5–NbC homogeneously distributed in a carbon nanofiber matrix. Polystyrene (PS), as the nanocrystallite growth modulator, plays a vital role in suppressing particle agglomeration. The in situ formed heterostructures with a rational interface engineering design can achieve effective LiPS regulation and speed up the redox kinetics, as confirmed by the density functional theory (DFT) calculations and experimental characterizations. As expected, the battery containing ultrafine Nb2O5–NbC heterostructures delivers long-term cyclability with a low capacity decay of 0.044% per cycle over 800 cycles at 1.0C. And the decay rate is as low as 0.045% after 250 cycles at 0.5C with a sulfur loading of 4.0 mg cm−2. This work provides a rational way to prepare ultrafine heterostructural polysulfide promotors via engineering the interface design for Li–S batteries.
研究领域:
能量存储系统
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材料科学
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电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 4
·2453-2465
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IF 3.9
Lanchao Wen,Jiaxin Zhang,Li Guan,Yujie Zhu,Biao Zhao,Limeng Song,Xinkai Zhu,Rui Zhang
Transition metal carbides (TMCs) are a class of materials with excellent dielectric properties and thermal stability, which exhibit enormous potential in high temperature electromagnetic wave absorption (EWA). However, the high dielectric constant and electrical conductivity of TMCs usually cause impedance mismatch, and their high density also prevents further practical applications. To solve these problems, the lightweight and impedance matching NbC nanowires (NbC nws ) were prepared by using bamboo powder as a carbon source and subsequent carbothermal reduction reaction process. The as-synthesized NbC nws all exhibit a low density of 0.23 g/cm 3 and superior EMA performance. It is worth noting that the minimum reflection loss (RL min ) of the sample is −43.03 dB at 5.92 GHz and the corresponding matching thickness is only 3.7 mm when sintering temperature is 1500°C. The excellent electromagnetic wave absorption (EWA) performance is attributed to good impedance matching and strong dielectric loss. This research work provides a prospect for the development and utilization of one-dimensional TMC materials in the field of microwave absorption materials.
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产品关联
DOI
高影响因子
MATERIALS TECHNOLOGY
·
2021
·
IF 3.846
Ling Chen,Yang Qin,Xinfu Cao,Jianbing Gao,Shishuo Liu,Yang Zhang,Jing Tu,Yingbo Wang,Jie Liu,Weidong He
In this study, a novel nitrated bacterial cellulose/2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/ammonium perchlorate nanoenergetic composite was successfully prepared by the sol–gel method and the freeze-drying technology. The structure and composition were characterised by means of scanning electron microscope, X-ray diffractometer and Fourier-transform infrared. The results demonstrated that the structure of the gel nanoparticles was granted with unique network cross-linked porous, wherein the hexaazaisowurtzitane and ammonium perchlorate nanoparticles were embedded and dispersed uniformly in the gel matrix. The thermal decomposition properties of composites were analysed by differential scanning calorimeter-thermogravimetric analysis, and the results revealed that the composites exhibited only two exothermal peaks which correspond to the nitrated bacterial cellulose/hexaazaisowurtzitane and ammonium perchlorate. In addition, the impact and friction sensitivities of composites were also performed and showed outstanding safety performance. Hence, this preparation strategy of nitrated bacterial cellulose-based nanocomposite energetic materials may provide promising application in high-performance and low-sensitivity propellants.
研究领域:
材料科学
·
能源与推进剂
✓ 已验证
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Ling Chen,Weidong He,Jie Liu
Benefiting from the sol–gel technology and vacuum freeze-drying technology, a novel nanoenergetic composite material nitrated bacterial cellulose (NBC)/CL-20 (hexanitrohexaazaisowurtzitane) has been fabricated. The thermal decomposition kinetic and mechanism have been studied by thermogravimetric analysis–differential scanning calorimetry (TG–DSC) under nonisothermal conditions in a nitrogen atmosphere at multiple heating rates; the process and mechanism of thermal decomposition of NBC/CL-201:1 have also been probed by TG–DSC–IR. The kinetic and thermodynamic parameters, such as activation energy (Ea), per-exponent factor (ln AK), rate constant (k), activation heat (ΔH⧧), activation free energy (ΔG⧧), and activation entropy (ΔS⧧) are calculated. The results indicate that NBC/CL-20 presents much lower activation energy than both of raw NBC and raw NC, and NBC/CL-201:1 exhibits superior thermal performance of heat release and Ea. Moreover, there the existence mechanism has also been probed between NBC and CL-20 during the process of thermal decomposition. The structure and composition have been characterized by a series of characterization methods and indicate that CL-20 has been embedded homogenously in the NBC gel matrix with a prominent porous cross-linked network structure. The impact and friction sensitivities have also been decreased. The whole process effectively avoids high temperatures, and thus ensures operational safety.
研究领域:
材料科学
·
热力学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xiaoqian Peng,Yingyi Li,Ziying Jiang,Kairuo Zhu,Qingda An,Zuoyi Xiao,Xiaoling Dong,Shangru Zhai
Heterogeneous catalysis with peroxymonosulfate (PMS) activation has received increasing attention in recalcitrant contaminants treatment, but multidimensional coupling via engineered biochar materials and photothermal synergy is still rare. Herein, we reported photothermal-synergistic PMS activation by Porphyra -derived porous biochar composites (ZnS/NBC) for carbamazepine (CBZ) degradation. Benefitting from the high specific surface area, highly graphitic structure and strong light-to-heat conversion ability, ZnS/NBC 10 /PMS/light system showed enhanced degradation performance and nearly complete mineralization of CBZ. Meanwhile, this system maintained high degradation efficiency in real water bodies and natural sunlight condition, respectively. Mechanism analysis confirmed that the predominant role of 1 O 2 and the auxiliary involvement of SO 4 − , OH and electron transfer jointly contributed to the CBZ degradation. Finally, the possible degradation pathways of CBZ were elaborated based on the liquid chromatography-mass spectrometry results and Fukui index calculations, and the diminishing ecotoxicity of the accompanying degradation intermediate was evaluated using the toxicity estimation software tool. This study provides a new insight for advancing a comprehensive utilization of photothermal conversion and biochar-based PMS activators to organic wastewater purification.
研究领域:
环境科学
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催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Water
·
2025
·Vol. 17
·期 11
·1700
·
IF 3
Xiaoni Lin,Qiang Ge,Xianbo Zhou,Yan Wang,Congyun Zhu,Kuanyong Liu,Jinquan Wan
Bimetallic catalysts can effectively enhance the catalytic degradation efficiency of peroxymonosulfate (PMS), which is usually attributed to the enhancement of electron transfer, but currently, there is no clear explanation of the mechanism of how the electron transfer is enhanced. A nitrogen-doped Fe/Mn composite biochar (FeMn-NBC) was co-constructed by hydrothermal synthesis and high-temperature calcination. The FeMn-NBC activated PMS more efficiently than the monometallic one due to the enhanced electron transfer between Fe and Mn. The FeMn-NBC/PMS system activated PMS with Mn as the active center, and the high oxidation state of Mn4+promoted the acceleration of the PMS adsorption of the generation of Mn2+/Mn3+. This gaining effect accelerated the electron cycling between Fe2+/Fe3+and Mn2+/Mn3+/Mn4+, which enhanced the PMS catalysis to generate free radicals (•OH, SO4•−and •O2−) and non-radicals (1O2) for the efficient degradation of diisobutyl phthalate (DIBP). Benefiting from this gaining effect, the degradation rate of DIBP by the FeMn-NBC/PMS system was increased by 2.43 and 3.38 times compared to Fe-NBC and Mn-NBC. The bimetallic-enhanced electron transfer mechanism proposed in this study facilitated the development of efficient catalysts for more efficient and selective removal of organic pollutants.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2026
·
IF 4.5
Xiaofang Liu,Ziyan Li,Meng Zhao,Xuan Pu,Xiaoxiao Xing,Ke Wang
Photodegradable polymers containing nitrobenzyl esters groups and their derivatives (e.g., nitrobenzyl carbonate, NBC) have attracted considerable attention due to their precise UV-triggered degradation. Herein, we designed a novel NBC-containing monomer of 7-methyl-1-(2-nitrophenyl)-3-oxo-2,4,10-trioxa-7-azadodecan-12-yl methacrylate (NBC–N-EOMA) by integrating ethoxy/amino groups with NBC via precise spatial arrangement, and synthesized its homopolymer of P(NBC-N-EOMA) through reversible addition-fragmentation chain transfer (RAFT) polymerization. P(NBC-N-EOMA) exhibited triple responsiveness to temperature, pH, and light: it has a lower critical solution temperature (LCST) in pH = 5 buffer and a critical pH in aqueous solution, both regulable by the length of ethoxy chain, polymerization degree and concentration. UV/vis spectroscopy showed that after UV irradiation, the intensity of characteristic peak (265 nm) of NBC units decreased with irradiation time. 1 H NMR further revealed the reduced peak area of the methylene group in NBC, directly confirming UV-induced photodegradation, which also altered the LCST and critical pH of P(NBC-N-EOMA). Additionally, photodegradation-induced color change enabled photolithographic patterning of P(NBC-N-EOMA) on paper. Amphiphilic P(NBC-N-EOMA) self-assembled into spherical micelles with size tunable via acid or UV, and enabled controlled release of Nile Red (NR) under multi-stimuli. It also functioned as a hydrophobic block in amphiphilic diblock copolymers, retaining validated triple responsiveness and self-assembly. This work features simplified synthesis (high conversion, controllable molecular weight), high and tunable responsiveness of the homopolymer (no inter-block interference), and expandability via diverse hydrophilic blocks. Such polymers hold promise in photodegradable materials, photolithographic patterning, and biomedicine.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 25
·9095-9102
·
IF 5.101
Xinyong Tao,Yiping Li,Jun Du,Yang Xia,Yingchao Yang,Hui Huang,Yongping Gan,Wenkui Zhang,Xiaodong Li
Finding a general procedure to produce a whole class of materials in a similar way is a desired goal of materials chemistry. In this work, we report a new bamboo-based carbothermal method to prepare nanowires of covalent carbides (SiC and B4C) and interstitial carbides (TiC, TaC, NbC, TixNb1−xC, and TaxNb1−xC). The use of natural nanoporous bamboo as both the renewable carbon source and the template for the formation of catalyst particles greatly simplifies the synthesis process. Based on the structural, morphological and elemental analysis, volatile oxides or halides assisted vapour–liquid–solid growth mechanism was proposed. This bamboo based carbothermal method can be generalized to other carbide systems, providing a general, one-pot, convenient, low-cost, nontoxic, mass production, and innovative strategy for the synthesis of carbide nanostructures.
研究领域:
材料化学
·
纳米材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）