MATERIALS & DESIGN
·
2018
·
IF 4.525
Jiaheng Wang,Siu Wing Or,Jun Tan
Core/shell/shell-structured Ni/SiO 2 /polyaniline hexagonal nanoflakes possessing in-plane [111] easy magnetization ( M ) and out-of-plane interfacial polarization ( P ) are synthesized by a three-step liquid chemical method , and their physicochemical properties and growth mechanism are investigated. Three characteristic types of paraffin-bonded ring-shaped nanoflake composites having random (R), vertical–horizontal (V–H), and horizontal–vertical (H–V) orientations of the orthogonal M and P to their two major surfaces are prepared by randomly, vertically, and horizontally aligning the nanoflakes in the paraffin matrix under a magnetic alignment and thermal curing process . The composites are evaluated experimentally and theoretically in the L–Ku (1–18 GHz) bands of microwaves in order to investigate the orientation effect of the orthogonal M and P on their microwave electromagnetic properties . The in-plane M in the H–V-oriented composite and the out-of-plane P in the V–H-oriented composite, which are parallel to the effective magnetic and electric field vectors of incident microwaves, result in a significant enhancement in permeability with multiple magnetic natural resonances and an obvious improvement in permittivity in comparison with other composites, respectively. The observations agree with the theoretical predictions based on the Landau–Lifshitz–Gilbert equation and Bruggeman's effective medium theory for permeability and the Debye's polarization theory for permittivity. As a result, the H–V-oriented composite achieves the best microwave electromagnetic impedance matching and absorption with a broad absorbing bandwidth of 4 GHz, a wide thickness range of 7–10 mm, and a minimal reflection loss of −41.5 dB in the Ku (12–18 GHz) band.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Jiehua Bao,Yuming Zhou,Yiwei Zhang,Yanyun Wang,Shuang Liang,Zhiwu Guo,Chang Guo,Yi Xue,Tao Zhuang,Yingjie Hu
In this study, we synthesized a series of Ni-based catalysts with different CeO 2 contents (0, 1, 2, 5 and 10 wt%) anchoring on the Al-Mg oxide spheres (AMO) with three-dimensional hollow flower-like structure. The triethoxyoctylsilane (TEOOS) and polyvinylpyrrolidone (PVP) were selected as effective modified reagents to introduce hydrophobic functionality on the surface of AMO and Ni-CeO 2 nanoparticles, respectively, for controllable anchoring Ni-CeO 2 nanoparticles on AMO by hydrophobic interaction driving mechanism. The effects of CeO 2 content on the texture, dispersion of Ni species, the reducibility of Ni 2+ , surface electronic states and acidity were investigated in detail. The Ni-5CeO 2 /AMO was found to achieve the highest 2,2′-bipyridine selectivity of 90.6% and maximum turnover number (TON) of 8611, specifically. Moreover, the Ni-5CeO 2 /AMO exhibits superior stability, maintaining 89% of 2,2′-bipyridine yield after 6 runs, due to the mitigated nickel leaching and promotion of the desorption of 2,2′-bipyridine. Furthermore, with the help of DFT calculations, a possible reaction mechanism was discussed and illustrated.
研究领域:
催化化学
·
材料科学
·
表面化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Junnan Wang,Qijie Wang,Wei Wang,Pinbo Li,Yazhen Zhao,Junjian Zhai,Wu Zhao,Han Zhang,Jiangni Yun,Zhiyong Zhang,Jiangxiao Tian,Zhouhu Deng,Junfeng Yan
In this study, a unique dual-spatial three-dimensional (3D) porous structure comprising Ni/C hollow microspheres was prepared from a Ni-based metal organic framework (Ni-MOF) embedded in graphene foam (GF) by the solvothermal method followed by calcination . The graphene foam-based composite, Ni/C@GF (NCGF), exhibited a stable spatial conductive network structure and diverse porous architecture, promoting the microwave absorption (MA) properties of composites. The NCGF with a Ni/C and GF ratio of 1:2.5 displayed a reflection loss (RL) value of ─63 dB with 15 wt% loading, while the thickness is only 1.76 mm. Further, its effective absorption bandwidth (EAB) reached to 5.4 GHz at 2 mm thickness. In addition, when the RL value is less than ─20 dB, the NCGF still manifests a wider bandwidth (2.2 GHz) and a relatively low thickness (1.76 mm). In addition to the extraordinary attenuation ability, the excellent MA performance is mainly ascribed to optimized impedance matching characteristics. Moreover, multiple reflections promoted by the dual-space structure also play a significant role during the microwave absorption process.
研究领域:
材料科学
·
纳米复合材料
·
电磁功能材料
·
物理化学
·
能源材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 6
·1-11
·
IF 2.8
Zhang Zhengyu,Yang Yujie,Chen Congliang,Chen Dongyang,Zhang Yingming,Meng Yuting,Li Hao
In this study, Ni–Zn–Co ferrite doped with (Al 3+ ) was synthesized by solid-phase synthesis method and its structure was analyzed. By analyzing the X-ray diffraction (XRD) data, it was explained that the Ni 0.45 Zn 0.40 Co 0.15 Fe 2-x Al x O 4 (0 ≤ x ≤ 0.15) ferrite has a single-spinel structure with FD-3 m space group. Additionally, by analyzing the XRD data, it is found that the lattice constant is the largest when Al 3+ is undoped. The range of lattice constant is (8.3751 ~ 8.3900) Å, the range of saturation magnetization ( M s ) is (68.77 ~ 79.39) emu/g, and the range of coercivity ( H c ) is (9.04 ~ 13.10) Oe. When the content of Al 3+ is 0.09, the permeability reaches the highest. In conclusion, the results obtained indicate that this ferrite is suitable for low-frequency electronic devices and also confirm that Fe 3+ was successfully replaced with Al 3+ . This paper provides a new idea for the study of spinel-structured ferrites by doping Al 3+ .
研究领域:
材料科学
·
固体物理
·
磁学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaohui Guan,Mohan Huang,Liu Yang,Guangsheng Wang,Xin Guan
In this paper, two-component nanocages containing CoS x and nickel-cobalt layered double hydroxides (Ni-Co LDH) were facilely synthesized via a multistep transformation approach. The zeolitic imidazolate framework-67 (ZIF-67) nanocrystals were firstly synthesized, and then after partial sulfuration, the CoS x /Ni-Co LDH nanocages were achieved by adding nickel ions for etching and precipitation. The prepared CoS x /Ni-Co LDH nanocages consisted of the hollow rhombic dodecahedral morphology with many nanosheets arrays on the shell. When used as electrode materials for electrochemical capacitors, this CoS x /Ni-Co LDH nanocages deliver a specific capacitance of 1562 F g −1 at a current density of 1 A g −1 . In addition, an asymmetric supercapacitor assembled with CoS x /Ni-Co LDH as cathode and active carbon (AC) as anode shows a high energy density of 35.8 Wh kg −1 at a power density of 800 W kg −1 and has an excellent cycling performance with the retention rate of 94.56% after 10,000 cycles, suggesting their potential application in high-performance electrochemical capacitors. These exceptional electrochemical properties can be attributed to the unique structure and synergistic effects between the metal sulfide and the bimetallic hydroxide, which also indicate the potential application of CoS x /Ni-Co LDH nanocages in high-performance supercapacitors.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xinhui Sun,Yanjie Chen,Mengmeng Ji,Weiya Zhang,Zhizhong Sun,Wenyi Chu,Xin Wang
Developing efficient bimetallic Ni/Zn metal organic frameworks (MOFs) derived Ni 3 ZnC 0.7 alloy catalyst for cyclization reactions is highly anticipated. Bimetallic Ni/Zn- PTA MOFs with flower-like microspheres morphology was synthesized by using a facile hydrothermal method and used as a precursor for preparation of the catalyst. Then, a ZnO supported Ni-Ni 3 ZnC 0.7 incorporated carbon catalyst (Ni-Ni 3 ZnC 0.7 /ZnO-C) was obtained by deriving from the Ni/Zn- PTA MOFs through one-step pyrolysis. The developed Ni-Ni 3 ZnC 0.7 /ZnO-C catalyst was used as a recoverable heterogeneous catalyst for synthesis of 2-arylbenzimidazoles by cyclization reaction of phenylmethanamines and 2-nitroanilines in good yields. Various characterizations (e.g. SEM/EDX, XRD, TEM, FT-IR, XPS and Raman) revealed that the catalyst exhibited good performance for cyclization reaction, which are ascribed to particular hierarchical structure, as well as synergistic effect between Ni and Ni 3 ZnC 0.7 . As a result, the Ni-Ni 3 ZnC 0.7 /ZnO-C catalyst showed excellent stability and activity for the condensation cyclization reaction. This bimetallic MOFs-derived Ni-Ni 3 ZnC 0.7 catalyst opens up a potential way for fabricating other Carbon supported alloy catalysts in heterogeneous catalysis reactions.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Rui Zhang,Yaoxin Yuan,Jinhong Li,Zhenxing Qin,Qingmei Zhang,Bangyun Xiong,Zesong Wang,Fenghua Chen,Xiujuan Du,Wen Yang
All-inorganic lead halide perovskite nanocrystals (NCs) as new emerging semiconducting luminescent materials have attracted tremendous attention for designing optoelectronic devices . We have synthesized high quality of the CsPbX 3 NCs with tunable entire visible spectral region by a modified lower temperature method, featured with facile, low-cost and easily operating in an open environment without vacuumization or glovebox system. Besides, we have investigated the incorporation of Ni and K ions into CsPbX 3 NCs by adjusting all kinds of composition concentration from halogen salts, based on above mentioned preparation method. The absolute photoluminescence quantum yields (PLQYs) of doped CsPbX 3 NCs with different dopant (Ni or K ions) concentration were discussed. It is found that a certain amount of doping is beneficial for suppressing the defects and improving the lattice structure of nanocrystals, whereas an excessive dopant may induce quenching centers of the emission. In addition, a glorious absolute PLQYs of doped CsPbX 3 NCs can be obtained by our method, especially for CsPbBr 3 and CsPbI 3 NCs, and nearly reach 80%.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2021
·Vol. 16
·期 4
·443-460
·
IF 4.204
Shi Yinteng,Ai Lin,Shi Haonan,Gu Xiaoyu,Han Yujun,Chen Jixiang
Carbon-coated Ni, Co and Ni-Co alloy catalysts were prepared by the carbonization of the metal doped resorcinol-formaldehyde resins synthesized by the one-pot extended Stöber method. It was found that the introduction of Co remarkably reduced the carbon microsphere size. The metallic Ni, Co, and Ni-Co alloy particles (mainly 10–12 nm) were uniformly distributed in carbon microspheres. A charge transfer from Ni to Co appeared in the Ni-Co alloy. Compared with those of metallic Ni and Co, the d -band center of the Ni-Co alloy shifted away from and toward the Fermi level, respectively. In the in-situ aqueous phase hydrodeoxygenation of methyl palmitate with methanol as the hydrogen donor at 330 °C, the decarbonylation/decarboxylation pathway dominated on all catalysts. The Ni-Co@C catalysts gave higher activity than the Ni@C and Co@C catalysts, and the yields of n -pentadecane and n -C 6 - n -C 16 reached 71.6% and 92.6%, respectively. The excellent performance of Ni-Co@C is attributed to the electronic interactions between Ni and Co and the small carbon microspheres. Due to the confinement effect of carbon, the metal particles showed high resistance to sintering under harsh hydrothermal conditions. Catalyst deactivation is due to the carbonaceous deposition, and the regeneration with CO 2 recovered the catalyst reactivity.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
·
2020
·
IF 3.744
Jie Sun,Lujiang Xu,Guo-hua Dong,Sonil Nanda,Hu Li,Zhen Fang,Janusz A. Kozinski,Ajay K. Dalai
Nickel-based catalysts with different supports and cobalt loadings were synthesized for hydrothermal gasification of cellulose at 350 °C. The activity of Ni catalysts was found in the order of Al 2 O 3 > spent bleaching clay ash > SiO 2 with H 2 yield of 80.6%, 69.0% and 57.0%. When 6 wt. % Co was added, 10Ni-6Co/Al 2 O 3 showed the highest H 2 yield of 88.4% i.e., 1.44 times that without Co addition. Catalysts were characterized by NH 3 -TPD, TPR, XRD, BET and XPS, showing that Ni-Co alloy formation promoted H 2 production. Single-factor experiments were conducted to study variables in the presence of 10Ni-6Co/Al 2 O 3 with the selected conditions of 0.5 g biomass and 20 min at 350 °C (achieving 94.9% H 2 yield from cellulose) for gasification of rice straw, peanut shell and cotton straw with the increase in H 2 yield by 51.4, 76.0 and 67.8 times. Ni-Co/Al 2 O 3 catalysts enhanced hydrothermal gasification of actual agricultural residues.
研究领域:
化学工程
·
环境科学
·
催化
·
可再生能源
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yunhua Song,Yang Yang,Shudi Mo,Donggang Guo,Lu liu
Construction of heterostructure engineered to modulate the electronic structure and enhance conductivity is an effective approach to enhance the performance of materials. The construction of heterostructure electrocatalysts with efficient catalytic activity by combining 2D nanosheet metal organic frameworks (MOFs) with other earth-rich transition metal oxide materials is a compelling study. Herein, a novel (Fe 2 O 3 ) 0.36 @Ni-MOF heterostructure nanosheets has been synthesized by a rapid one-pot hydrothermal procedure as an efficient OER catalyst. (Fe 2 O 3 ) 0.36 @Ni-MOF exhibited prominent OER property with the overpotential of 230 mV at10 mA cm −2 , a small Tafel slope of 66.7 mV dec −1 and ignorable activity decay after 20 h long-term test at 10 mA cm −2 . The excellent properties of (Fe 2 O 3 ) 0.36 @Ni-MOF nanocomposite could be attribute to the vast amounts of active sites exposed by the nanosheets and ultrasmall size nanoparticles, and the electronic interaction between Fe 2 O 3 and Ni-MOF in the heterostructure. This work presents an attractive tactics for the preparation of heterostructure catalysts with good OER catalytic performance.
研究领域:
材料科学
·
电化学
·
纳米技术
·
催化
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 16
·7792-7800
·
IF 11.301
Tian Gan,Xinqiang Fan,Ye Liu,Chengyu Wang,Haoran Mei,Lijun Fan,Nianjun Hou,Yicheng Zhao,Yongdan Li
Ni/Ce0.8Sm0.2O1.9 (SDC) with a three-dimensionally ordered macroporous (3DOM) structure is prepared with poly(methyl methacrylate) as the template and characterized using X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, H2 temperature-programmed reduction, X-ray photoelectron spectroscopy and ultraviolet Raman spectroscopy. Lattice oxygen in 3DOM SDC shows a higher activity than that in hydrothermally synthesized bulk SDC. 3DOM SDC also exhibits a stronger interaction with Ni compared to bulk SDC, which facilitates the release of lattice oxygen and the formation of oxygen vacancies in SDC in a reducing atmosphere. Therefore, Ni/3DOM SDC shows a much higher catalytic activity for electrochemical oxidation than Ni/bulk SDC as the anode material of solid oxide fuel cells. With Ni/3DOM SDC as the anode, a cell supported by a 500 μm-thick SDC-carbonate composite electrolyte layer exhibits maximum power densities (Pmax) of 1.28 and 1.63 W cm−2 at 700 °C with H2 and methanol as fuels, respectively, more than twice the Pmax of a similar cell with a Ni/bulk SDC anode. The Ni/3DOM SDC anode also shows a high resistance to coking.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
BMC Chemistry
·
2019
·Vol. 13
·期 1
·1-15
·
IF 0
Guo J.,Ma Yu L.,Yu Jia Y.,Gao Yu J.,Ma Ning X.,Wu Xiao Y.
Herein, 2-(2-methoxyphenoxy)-1-phenylethanol (β- O -4), 2-methoxyphenyl anisole (α- O -4) and 4-phenoxyphenol (4- O -5) were selected as typical lignin model compounds. Given the effectiveness of traditional acid–base catalysts for lignin depolymerisation, a novel Ni/CaO–H-ZSM-5(60) catalyst was prepared to investigate the difficulty level of C–O bond of three model compounds cleavage in ethanol. It was observed that Ni/CaO–H-ZSM-5(60) had prominent performance on the C–O bond cleavage at very mild conditions (140 °C, 1 MPa H 2 ). Among them, the C–O bond of α- O -4 and β- O -4 could be completely cleaved within 60 min. Although the C–O bond of 4- O -5 had high bond energy, 41.2% of conversion was occurred in 60 min. The introduction of CaO could regulate the acidity of H-ZSM-5 to enhance the ability to break C–O bonds. Moreover, the possible pathways of C–O ether bonds in three lignin model compounds cleavage were proposed in order to selectively obtain target products from the raw lignin degradation.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）