COMPOSITES COMMUNICATIONS
·
2025
·
IF 7.7
Liqiang Shang,Hao Zheng,Jiali Chen,Yiming Ren,Wenge Zheng,Bin Shen
Construction of conductive polymer composites (CPCs) for green electromagnetic interference (EMI) shielding with efficient shielding effectiveness (SE) but low EM reflection is urgently needed. Though the introduction of cellular or gradient structures can effectively reduce EM reflection, most current methods for preparing gradient CPC foams are relatively complex and lack sufficient applicability for large-scale production. Herein, we demonstrate the convenient fabrication of gradient-structured EVA/carbon nanostructure (CNS) foams through chemical foaming of thermally molded EVA/CNS composites with gradient CNS construction. Compared to uniform EVA/CNS foams, lower R coefficient with an effective EMI SE of >20 dB was obtained for gradient EVA/CNS foams with 3 phr CNS, accompanied by an average green shielding index (g s ) of ∼2.8. This study provides a more feasible two-step process of thermal press molding and chemical foaming for mass manufacturing of gradient CPC foams with effective green EMI shielding characteristics.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Luyao Guo,Mengru Wang,Ronghe Lin,Jiaxin Ma,Shuanghao Zheng,Xiaoling Mou,Jun Zhang,Zhong-Shuai Wu,Yunjie Ding
Synthesis of new carbon nanostructures with tunable properties is vital for precisely regulating electrochemical performance in the wide applications. Herein, we report a novel approach for the oxidative polymerization of N- and P-bearing copolymers from the self-assembly of three different monomers (aniline, pyrrole, and phytic acid), and further prepare the respective carbon nanostructures with relatively consistent N dopant (6.2%–8.0%, atom) and varying P concentrations (0.4%–2.8%, atom) via controllable pyrolysis . The impacts of phytic acid addition on the compositional, structural, and morphological evolution of the copolymers and the resulting nanocarbons are well studied through a spectrum of characterizations including N 2 sorption , Fourier transform infrared spectroscopy, gel permeation chromatograph, scanning/transmission electron microscopy, and X-ray photoelectron spectroscopy. Gradual fragmentation of the nanosphere structures is evidenced with increasing addition of phytic acid, leading to different nanostructures from hollow nanospheres to 3D aggregates. Nanocarbons decorated with N and P dopants from pyrolysis are further utilized as anode materials in lithium-ion batteries, demonstrating enhanced electrochemical performance, i . e ., a reversible capacity of 380 mA·h·g −1 at 2 A·g −1 for NPC-0.5 during 200 cycles. The superior performance originates from the balanced porosity, and appropriate concentrations of P and pyrrolic N, thus pointing the direction for designing high-performance anode materials.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ali Reza Kamali,Haoyu Zhao
Natural graphite mineral (NGM) is an abundant and low-cost carbon source with the potential of being employed as the precursor for producing high-quality carbon nanostructures for energy storage applications. In this article, one-pot electrochemical conversion of NGM into graphitic carbon nanostructures incorporated with Fe 3 Si nanocrystals with enhanced bulk electrical conductivity and Li-ion storage performance is reported. To this end, electrodes made of NGM are negatively polarized in molten LiCl-NaCl at 740 °C under various cathode current densities. At 1 A cm −2 , the high-yield conversion of the mineral into carbon nanotubes (CNTs), nanofibers and onion-like carbon nanoparticles is realized. The product exhibits a specific electrical conductivity of 9.83 S m 2 g −1 , and the Li + transfer resistance of 24 Ω. The Li-ion storage capacity of the material is evaluated to be high at 382 mAh g −1 after 220 Li-ion insertion and extraction cycles under the current density of 200 mA g −1 , making the material an attractive low-cost candidate for the anode of lithium ion batteries . The ferromagnetic behavior of the nanostructured Fe 3 Si incorporated carbon is characterized by the saturation magnetization of 11.1 emu g −1 , potentially promoting the recyclability of spent anode material . This article reports on the green and low-cost conversion of NGMs into nanostructured carbon materials with enhanced Li-ion storage performance.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2022
·
IF 8.431
Liang Luo,Qiang He,Siqi Chen,Dongxu Yang,Yi Chen
Flow-electrode capacitive deionization (FCDI) has shown a robust desalination performance, in which the electrode materials play a crucial role. However, commercial activated carbon (AC) commonly with relatively poor conductivity, which can be a limit to the desalination process . To address this issue, we successfully prepared ZIF-8 derived nanocarbon materials (Zx, X = 0, 1, 2, 3, the number representing the activator ratio) via a pyrolysis activation procedure as electrode materials for FCDI desalination. The results manifested that Z3 achieved desalination rates of 0.0403 and 0.094 mg min −1 cm −2 in the isolated closed cycle (ICC) and the short-circuited closed cycle (SCC) mode, respectively, at 1.2 V with only 5 wt% carbon loading. The desalination rate of Z3 in the SCC mode was improved with flow rates and influent salt concentrations increase, reaching 0.278 mg min −1 cm −2 under a continuous operation. In the ICC mode, it was found that the adsorption capacity of the Zx sample was positively correlated with its specific surface area. The superior performance of Z3 could be attributed to the high conductivity, large specific surface area and well-developed pores. Overall, this work provided new insights and references for electrode material's application to FCDI desalination.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Zhaoxing Wu,Zhengxiong Wu,Yulai Zhao,Linxi Hou
The electrochemical reduction of CO2 to produce high-value multicarbon products represents a challenging yet highly desirable process, particularly due to the inefficient C–C coupling observed in current electrocatalysts. In this study, Cu2+ and Co2+ were introduced into ZIF-8 as precursors to synthesize a series of Co- and CuCo-doped carbon nanostructure materials with varying Co-to-Cu ratios. X-ray diffraction and X-ray photoelectron spectroscopy (XPS) analyses confirmed the successful doping of metal Co in the form of Co–Nx, while Cu was partly doped as nanoparticles attached to the carbon substrate surface and partly as single atoms forming Cu–Nx. Transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed uniform distribution of elemental Co and Cu on the carbon substrate, with Cu loaded as nanocluster on the surface. Linear sweep voltammetry tests indicated that Cu/CoCu-Nx-C composites exhibited enhanced reactivity toward CO2 reduction compared to other samples. At −0.19 V (vs RHE), the Faradaic efficiencies (FEs %) of C2H4, C2H6, CH4, CO, and H2 over Cu/CoCu-Nx-C were 29.7, 8.6, 20.2, 9.8, and 31.5%, respectively. The influence of Co and Cu doping modes on the selectivity of electrocatalytic reduction products was investigated. Results showed that Cu/CoCu-Nx-C exhibited a higher FE of C2 compared to Cu/Cu–Nx-C, with nearly 10 times higher C2 current density. Mechanistic insights from acid-etching experiments and XPS revealed a synergistic interaction between metallic Co and Cu, promoting the generation of multicarbon products. Co–Nx improved *CO coverage, facilitating subsequent C–C coupling on neighboring Cu–Nx. Additionally, CH4 production was attributed to the (111) crystalline facets in the Cu nanocluster and isolated Cu–Nx. Overall, this research provides an important understanding of the creation of straightforward and effective catalysts for the reduction of CO2. It holds considerable potential for the production of hydrocarbons using carbon dioxide.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 10
·1652
·
IF 5.719
Qi Chen,Haichao Li
Carbon nanostructures (carbon nanotubes, nano carbon spheres, layered carbon nanostructures) were prepared from a sodium dodecyl sulfonate @ sodium chloride system. Sodium dodecyl sulfonate was used as a carbon source. A sodium chloride crystal in the carbonization procedure was used to separate ordered aggregates of sodium dodecyl sulfonate. The results show that different carbon nanostructures were prepared at low concentrations (1CMC~5CMC) by controlling the concentration of sodium dodecyl sulfonate, such as nano carbon spheres and carbon nanotubes, and that layered carbon nanostructures were formed at high concentrations (10CMC). The prepared carbon nanostructures were characterized by transmission electron microscopy, fluorescence spectrometry and Raman spectrometry. The results of this experiment show that the surfactant @ salt system is a potential method for the preparation of carbon nanostructures.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Lili Yan,Min Zhang,Shichao Zhao,Tijian Sun,Bin Zhang,Maosheng Cao,Yong Qin
Yolk–shell and one-dimensional structures are promising microwave absorption structures due to the microwave multi-reflection and scattering sites of yolk–shell structure, and the conductive network that is easily formed by one-dimensional structure. The wire-in-tube structure may be a more effective microwave absorption structure because it combines the advantages of one-dimensional and yolk–shell structures. However, conventional methods are difficult to realize such a structure because of the weak controllability of the structure, and it is impossible to tune the absorption band or optimize the absorption performance by precisely tailoring the structure. Molecular layer deposition (MLD), with excellent structure controllability, is an effective strategy to overcome this problem. In this work, a novel wire-in-tube ZnO@carbon nanostructure was realized by polyimide MLD–calcination strategy. The ZnO cores and carbon shells form voids between them by a redox process during calcination, conducive to microwave multi-refection and scattering. More importantaly, by tuning the number of deposition cycles, the carbon shell thickness can be adjusted at the atomic scale so as to modulate the absorption bands effectively. Maximum absorption of −50.05 dB and a bandwidth of 5.68 GHz are simultaneously achieved at a matching thickness of 2.0 mm. The polyimide MLD–calcination strategy not only provides a novel wire-in-tube structure with remarkable microwave absorption performance, but diversifies carbonaceous material fabrication methods, extending the applications to supercapacitors, sensing, catalysis, and the biomedical fields.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Haiying Wang,Dun Wei,Yingjie He,Haoyu Deng,Bichao Wu,Lvji Yan,Haiyin Gang,Yiyun Cao,Linfeng Jin,Liyuan Zhang
Electrochemical deionization (EDI) is hopefully the next generation of water treatment technology. Bismuth (Bi) is a promising anode material for EDI, due to its high capacity and selectivity toward Cl–, but the large volume expansion and severe pulverization aggressively attenuated the EDI cycling performance of Bi electrodes. Herein, carbon-layer-encapsulated nano-Bi composites (Bi@C) were prepared by a simple pyrolysis method using a Bi-based metal–organic framework as a precursor. Bi nanoparticles are uniformly coated within the carbon layer, in which the Bi–O–C bond enhances the interaction between Bi and C. Such a structure effectively relieves the stress caused by volume expansion by the encapsulation effect of the carbon layer. Moreover, the introduction of a carbon skeleton provides a conductive network. As a consequence, the Bi@C composite delivered excellent electrochemical performance with a capacity of 537.6 F g–1 at 1 mV s–1. The Cl– removal capacity was up to 133.5 mg g–1 at 20 mA g–1 in 500 mg L–1 NaCl solution. After 100 cycles, the Bi@C electrode still maintains 71.8% of its initial capacity, which is much higher than the 26.3% of the pure Bi electrode. This study provides a promising strategy for improving EDI electrode materials.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
Xu Nuoxin,Zhang Qilong,Yang Hui,Xia Yuting,Jiang Yongchang
Novel three-dimensional hierarchical flower-like TiO 2 /carbon (TiO 2 /C) nanostructures were in-situ synthesized via a solvothermal method involving calcination of organic precursor under inert atmosphere. The composite films comprised of P (VDF-HFP) and as-prepared hierarchical flower-like TiO 2 /C were fabricated by a solution casting and hot-pressing approach. The results reveal that loading the fillers with a small amount of carbon is an effective way to improve the dielectric constant and suppress the dielectric loss. In addition, TiO 2 /C particles with higher carbon contents exhibit superiority in promoting the dielectric constants of composites when compared with their noncarbon counterparts. For instance, the highest dielectric constant (330.6) of the TiO 2 /C composites is 10 times over that of noncarbon-TiO 2 -filled ones at the same filler volume fraction, and 32 times over that of pristine P (VDF-HFP). The enhancement in the dielectric constant can be attributed to the formation of a large network, which is composed of local micro-capacitors with carbon particles as electrodes and TiO 2 as the dielectric in between.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
iScience
·
2023
·
IF 5.8
Cheng Wang,Zirui Qiao,Yulan Tian,Haijun Yang,Huaqiang Cao,Anthony K. Cheetham
Imines are important intermediates for synthesizing various fine chemicals, with the disadvantage of requiring the use of expensive metal-containing catalysts. We report that the dehydrogenative cross-coupling of phenylmethanol and benzylamine (or aniline) directly forms the corresponding imine with a yield of up to 98%, and water as the sole by-product, in the presence of a stoichiometric base, using carbon nanostructures as the “green” metal-free carbon catalysts with high spin concentrations, which is synthesized by C(sp 2 )-C(sp 3 ) free radical coupling reactions. The catalytic mechanism is attributed to the unpaired electrons of carbon catalysts to reduce O 2 to O 2 ·− , which triggers the oxidative coupling reaction to form imines, whereas the holes in the carbon catalysts receive electrons from the amine to restore the spin states. This is supported by density functional theory calculations. This work will open up an avenue for synthesizing carbon catalysts and offer great potential for industrial applications.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
Research
·
2020
·
IF 0
Hongye Yan,Linzhe Wang,Yifeng Chen,Lei Jiao,Yu Wu,Weiqing Xu,Wenling Gu,Weiyu Song,Dan Du,Chengzhou Zhu
Carbon materials have been widely used as nanozymes in bioapplications, attributing to their intrinsic enzyme-like activities. Nitrogen (N)-doping has been explored as a promising way to improve the activity of carbon material-based nanozymes (CMNs). However, hindered by the intricate N dopants, the real active site of N-doped CMNs (N-CMNs) has been rarely investigated, which subsequently retards the further progress of high-performance N-CMNs. Here, a series of porous N-CMNs with well-controlled N dopants were synthesized, of which the intrinsic peroxidase (POD)like activity has a positive correlation with the pyridinic N content. Density functional theory calculations also reveal that pyridinic N boosts the intrinsic POD-like activity of N-CMNs. Pyridinic-N dopant can effectively promote the first H2O desorption process in comparison with the graphitic and pyrrolic N, which is the key endothermic reaction during the catalytic process. Then, utilizing the optimized nanozymes with high pyridinic N content (NP-CMNs) and superior POD-like activity, a facile total antioxidant capacity (TAC) assay was developed, holding great promise in the quality assessment of medicine tablets and antioxidant food for healthcare and healthy diet.
研究领域:
材料科学
·
生物医学工程
·
催化化学
✓ 已验证
DOI
CARBON
·
2021
·
IF 9.594
Khaled Tawfik Alali,Jing yu,Deema Moharram,Qi Liu,Rongrong Chen,Jiahui Zhu,Rumin Li,Peili Liu,Jingyuan Liu,Jun Wang
Hierarchical 3-dimensional (3D) carbon nanostructures have potential applicability in several electrochemical energy applications own to their sizeable effective surface, specific energy density , cycling stability and flexibility. Herein, combining electrospinning with in situ chemical vapor deposition (CVD) technologies as an efficient and secure procedure is applied for constructing 3D carbon nanostructure-based on carbon fibers (CFs) and electrospun carbon nanofibers (ECNFs). Affect the catalysis type, immersion solution, carbon sources and treat temperature are experimentally demonstrated. Cactus-like 3D carbon nanomaterials are constructed via growth forest-like carbon nanofibers (CNFs) directly on both CNFs and CFs at 900 °C using Ni as a catalyst, cellulose acetate (CA) as carbon source and ethanol-urea as an immersions solution. The Ni/CNFs/ECNFs mat exhibits a large surface area of 342.3 m 2 g −1 , while just 19.3 m 2 g −1 is recorded to Ni/CNFs/CFs. Based on the nano-nonwoven structure and forest-like grown CNFs nanostructure, Ni/CNFs/ECNFs exhibit a favorable hydrogen evolution reaction (HER) performance in an alkaline medium with a low overpotential of 88 mV to deliver 10 mV cm −2 current density and Tafel slope of 170 mV dec −1 . This work proves the synthesis parameters of 3D hierarchical carbon nanostructures and their enticing to apply as an advanced substrate for electrochemical applications.
研究领域:
材料科学
·
电化学
✓ 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）