CARBON
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2025
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IF 11.6
Sain Bux Jamali,Tauqeer Haidar Qamar,Sibt ul Hassan,Nouman Ahmed,Farhan Ali,Shakeel Ahmad,Shengxiang Huang,Lianwen Deng
A facile and scalable polymer bubbling technique was used to fabricate three-dimensional nickel-embedded nitrogen-doped porous carbon foams (3D Ni@NPCFs) exhibiting high-performance electromagnetic wave absorption. The 3D Ni@NPCFs were characterized by their unique 3D interconnected porosity and the cooperative effect of conductive magnetic Ni nanoparticles and nitrogen incorporation. The optimal sample achieved reflection loss (RL) of -47.20 dB at 6.05 GHz and an effective absorption bandwidth (EAB) of 7.4 GHz within the absorber thickness of 3.0 mm. This superior performance is attributed to the unprecedented synergistic interplay between the tailored 3D porous network, which facilitates multiple scattering and prolonged wave propagation, and the embedded Ni nanoparticles coupled with nitrogen doping, which enhances both the magnetic and dielectric losses. Furthermore, the optimal sample demonstrated a simulated radar cross-sectional reduction of up to 28.43 dBm 2 . The 3D Ni@NPCFs show great promise as high-performance absorbers for electromagnetic protection applications.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Wenjuan Wang,Yan Zhao,Yongguang Zhang,Ning Liu,Zhumabay Bakenov
Due to the demands for high performance and ecological and economical alternatives to conventional lithium-ion batteries (LiBs), the development of lithium-sulfur (Li-S) batteries with remarkably higher theoretical capacity (1675 mA h g −1 ) has become one of the extensive research focus directions worldwide. However, poor conductivity of sulfur, critical cyclability problems due to shuttle of polysulfides as intermediate products of the cathodic reaction, and large volume variation of the sulfur composite cathode upon operation are the major bottlenecks impeding the implementation of the next-generation Li-S batteries. In this work, a unique three-dimensional (3D) interconnected macrocellular porous carbon (PC) architecture decorated with metal Ni nanoparticles was synthesized by a simple and facile strategy. The as-fabricated Ni/PC composite combines the merits of conducting carbon skeleton and highly adsorptive abilities of Ni, which resulted in efficient trapping of lithium polysulfides (LiPSs) and their fast conversion in the electrochemical process. Owing to these synergistic advantageous features, the composite exhibited good cycling stability (512.3 mA h g −1 after 1000 cycles at 1 C with an extremely low capacity fading rate 0.03 % per cycle), and superior rate capability (747.5 mA h g −1 at 2 C). Accordingly, such Ni nanoparticles embedded in a renewable puffed corn-derived carbon prepared via a simple and effective route represent a promising active type of sulfur host matrix to fabricate high-performance Li-S batteries.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Hongyu Chen,Zengxuan Chen,Shoufu Cao,Zhaojie Wang,Xiaodong Chen,Xiaojing Lin,Qi Hou,Shuxian Wei,Siyuan Liu,Baojun Wei,Xiaoqing Lu
Nitrogen-doped carbon (NC) for carbon dioxide reduction reaction (CO 2 RR) are promising candidates. However, its selectivity and activity are limited by the undeveloped pore and limited electronic effect. Herein, we propose a strategy of three birds with one stone to utilize the embedded nickel for inducing electron-rich pyridinic-NC with multimodal porous structure based on the hard template assisted sacrificial template method. Nickel acts as sacrificial agent and inducer to facilitate the formation of mesoporous and reactive nitrogen species for capturing and activating reactants, respectively. Besides, we find that nickel as electron donor endows the NC with electron accumulation for participating actively in PCET reaction. The resultant Ni 0.87 -NC-1-AE exhibits an eminent FE CO of 97.6 % with excellent activity and stability. In-situ Raman spectroscopy and the projected crystal orbital Hamilton populations (pCOHP) confirm the accumulation of *COOH and the stable adsorption of *COOH on the surface. What’s more, the well-designed experiments and DFT calculations accurately locate pyridinic-N as the active site, where the aggregated electrons donated by nickel significantly reduce the energy barrier of rate-determining step and promote the desorption of CO. This work provides an instructive perspective to construct advanced NC electrocatalysts with high mass transfer efficiency and high catalytic activity.
研究领域:
材料科学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Liang Gao,Qianqian Xiao,Chengxi Wang,Jing Sun,Funing Zhang,Xuan Wang
In the realm of advanced electrical equipment and systems, polymer nanocomposites possess significant application value due to their excellent dielectric properties. Metal@ceramic fillers with a core-shell structure can enhance the dielectric constant ( ε ′) of polymer nanocomposites; however, their application is limited by the high dielectric loss (tan δ ). A magnetic field tailoring strategy is introduced in this article to significantly improve the dielectric properties of poly(vinylidene fluoride) (PVDF) composites. Magnetic CaCu 3 Ti 4 O 12 –Ni (CN) composite fibers are formed by embedding Ni nanoparticles within CaCu 3 Ti 4 O 12 (CCTO) fibers. Furthermore, the CN fibers are horizontally orientated in the PVDF matrix by tailoring the optimal magnetic field to 1.0 T–150 ℃. This results in a significant increase in the ε ′ of 25, which is 92 % and 194 % higher than that of a CN fiber without magnetic field treatment and pure PVDF, respectively, while maintaining a low tan δ of 0.08. Experimental and simulation results indicate that the magnetic orientation tailoring enhances the multi-interface polarization, especially the inner interfacial polarization (△ P in ) at the CCTO/Ni interfaces, dominantly improving dielectric performance, as evidenced by the high interfacial polarization strength, △ ε 2 ∼ 141.51, the low activation energy, E a ∼ 0.81 eV, and the large △ P in ∼ 1.06×10 4 μC/m 2 . This magnetic orientation tailoring strategy offers a new paradigm and significant guidance for the development of polymer dielectrics with exceptional dielectric properties.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Zhichao Tan,Ke Du,Zhizheng Sheng,Wanyi Li,Huihong Zhu,Lou Gao,He Li,Yi Tang,Yahong Zhang
Herein, an Al-containing MFI zeolite subcrystal (Al-MFI-SC) with a size less than 7 nm and extracted from the synthetic system of ZSM-5 zeolites was employed as an acidic support to disperse metal nickel (Ni) species. Various characterization results confirmed its ultrasmall size, large external surface area, uniformly accumulated mesoporous structure, and abundant weak acidity. Different from Ni species supported on nano and commercial HZSM-5 zeolites, Ni nanoparticles, similar in size to Al-MFI-SC, were discretely embedded in the Al-MFI-SC support, achieving a stable high dispersion of Ni species in it. As a result, the prepared Ni-embedded zeolite subcrystal (Ni/Al-MFI-SC) catalyst exhibited surprisingly high activity in the hydrodesulfurization (HDS) of 4,6-dimethyl-dibenzothiophene. The turnover frequency (TOF) of its desulfurization was 6.2 and 10.1 times higher than that of Ni species supported on nano and commercial HZSM-5 zeolites, respectively, which is attributed to its high dispersed Ni species, abundant accessible acidic sites and unique micro–mesoporous structure. Moreover, this Ni/Al-MFI-SC catalyst displayed a high desulfurization performance in the presence of metalloporphyrin compounds and high reaction stability, which can be attributed to the large external surface area of the zeolite subcrystal carrier and stable HDS ability of Ni species. This study demonstrates the significance of zeolite subcrystals with ultrasmall size, appropriate acidity, and short diffusion channels as ideal catalysts and metal carriers for bulk molecule conversion.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）