JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 4
·3365-3377
·
IF 2.195
Shen Yongqian,Wei Yupeng,Li Jian,Li Qinglin,Ma Jiqiang,Wang Pingbo,Li Bin,He Wenbo,Du Xueyan
High-performance microwave absorbers with excellent absorption ability and superhydrophobic property are extremely significant for the application of stealthy techniques, especially in high-humidity environment. In this research, high-performance Co-C nanofibers (NFs) were prepared via electrospinning mathod by using of poly (vinyl alcohol) (PVA) and Cobalt acetate tetrahydrate (CoAc) solution as precursor with subsequent PVA pyrolyzation and carbonization process. The electromagnetic (EM) parameters and microwave absorption performance of the prepared NFs were investigated with the microwave frequency ranging from 2.0 GHz to 18.0 GHz. Analysis and comparison were performed on the impedance matching and loss mechanisms of each sample. The experimental results indicated that the sample calcinated at 950 °C achieved an optimal reflection loss (RL) of − 33.1 dB and an effective frequency bandwidth of 4.1 GHz under a thickness of 1.5 mm; and that the Co-C NFs membrane with the optimal absorption performance exhibited superhydrophobic property with a contact angle (CA) of 152°, suggesting their promising application to water-resistant stealthy materials.
研究领域:
材料科学
·
电磁材料
·
纳米技术
·
隐身技术
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2022
·
IF 9.463
Xiu-Zhi Tang,Zijian Liao,Haolong Shi,Rong Wang,Jianling Yue,Xuelong Chen
Electromagnetic wave (EMW) absorption materials have recently received considerable attention due to the increasingly severe EMW pollution. It remains challenging to fabricate a lightweight absorber with high absorption performance and low matching thickness via structure design and composition tuning. Herein, one type of fibrous composite EMW absorber with two-dimensional (2D) nanosheets coating was synthesized by electrospinning, pyrolysis and hydrothermal. The combination of cobalt nanoparticle and carbon nanofiber with decoration of 2D MoSe 2 nanosheets on the surface significantly promote the EMW absorption through dielectric/magnetic loss, impedance matching, diverse polarizations and porous structure induced multiple scattering. Owing to the coupling effect of proper combination of multiple components and hierarchical structure, a strong EMW absorption with minimum reflection loss (RL) −62.30 dB at 10.70 GHz, effective absorption bandwidth (EAB) 5.10 GHz (9.30–14.40 GHz) covering most of the X-band was achieved with absorber thickness of 2.05 mm. By adjusting the thickness to 1.60 mm, the EAB can reach 6.00 GHz (12.00–18.00 GHz), covering the whole Ku bands. This composite fibrous absorber with excellent EMW absorption performance is promising to be used in many EMW attenuation applications.
研究领域:
材料科学
·
电磁工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Bingyang Liu,Yu Wang,Xue Hao,Xuetao Liang,Qi Yang
In this work, a carbon-based catalyst Fe/Co@C with MOF as a self-sacrificing template was prepared by high-temperature roasting of FeCo-MIL101, which was applied to activate PMS for the degradation of chlorotriazine herbicides (ATZ and SIM) showing excellent performance. Characterization analysis revealed that Fe/Co@C possesses a certain graphene structure and has a saturation magnetization rate of 0.87 emu/g, which can be separated from the solution easily and quickly. The degradation of ATZ and SIM was enhanced by introducing chloride ions into the system, and 100 mmol/L Cl - could lead to the complete removal of ATZ and SIM in 6 min, while improving the interfacial electron transfer of Fe/Co@C/PMS. In combination with quenching experiments, ESR test results and DFT calculations, two important roles of chlorine radicals in the reaction are proposed: (1) direct electron transfer and (2) indirect promotion of 1 O 2 generation through the production of HOCl. In addition, the testing of the influencing factors of the catalyst in the system (catalyst dosing, PMS dosing, pH, temperature), the testing of coexisting anions in the aqueous matrix, and the reusability all showed satisfactory performance. Finally, the degradation mechanisms of ATZ and SIM were proposed in combination with GC–MS determination of contaminant intermediates and analysis of their toxicity.
研究领域:
环境科学
·
催化
·
水处理
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Haochang Chen,Shunzhe Zhang,Shaoping Wu,Kaifeng Wang,Chi Chen,Yujie Chen,Wenshuang Chu,Zhen Chen,Hua Li,Hezhou Liu
Nano-sized two-dimensional carbonaceous materials have been widely used as the matrix for alloying-type and conversion-type anode materials for Li-ion batteries (LIBs) to improve structural stability and rate performance. However, relevant synthesis usually requires rigorous conditions and chronic reaction processes. Herein, we have designed a simple solvothermal reaction and heat treatment to prepare a novel CoO/Co/C two-dimensional nanosheet (CoO/Co/C 2DNS) by adopting cellulose nanofibers (CNFs) as the precursor. The unique characteristics of CNFs facilitate the uniform distribution of active materials on the surface and the construction of two-dimensional nanostructure via self-assembly. It is worth noting that CoO/Co/C 2DNS exhibits a striking synergistic effect since the porous 2D carbon framework offers additional pseudo-capacitance and enhances the electronic conductivity, while the ultrafine active materials encapsulated inside shorten the Li-ions diffusion pathways and relieve the volume change. Benefit from the unique structure, the composite anode delivered outstanding rate performance (∼500 mAh g −1 at 10 A g −1 ) and superior long-range cycling performance up to 800 cycles even at 2 A g −1 . This work provides a new strategy for the synthesis of nano-sized 2D composite, offering a promising route to construct high performance conversion-type anodes for next-generation LIBs.
研究领域:
材料科学
·
能源存储
·
纳米技术
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2023
·
IF 4.5
Jifang Zhang,Chengcheng Suo,Jinde Sun,Wei Li,Sha Luo,Chunhui Ma,Shouxin Liu
In this study, C α –C β and C β –O bond cleavage of β-O-4 model compound (2-phenoxy-1-phenylethanol) were accomplished by electrocatalysis depolymerization process in deep eutectic solvents (DES) systems. We have investigated the application of Ni-Co/C catalysts on working electrode, which were synthesized with impregnation method. The Ni-Co/C with porous structure and abundant active sites, was shown an excellent electrocatalysis activity. Specific structure of Ni-Co/C could provide greatly efficient adsorption and desorption capacity to promote C α –C β and C β –O bond cleavage. Therefore, in this electrocatalysis depolymerization process, the highest depolymerization rate exceeded 90%. And the yields (and conversion rates) of products (including benzaldehyde, acetophenone, benzoic acid, phenol) can reach to 124.08 mg/g (25.05%), 23.29 mg/g (4.15%), 44.64 mg/g (7.83%), 30.3 mg/g (6.9%). Furthermore, the electrocatalysis mechanism of C α –C β and C β –O bond was investigated. The cleavage of C α –C β and C β –O bond was initiated by in situ generated free radicals through Ni-Co/C. Then, the cleavage of C α –C β and C β –O bond were occurred by ·OH and ·O 2 − . The results were showed that the C α –C β bond cleavage was more in line with the β-C elimination and free radical pathways, and C β –O bond cleavage was consistent with direct oxidative addition. The enhanced electrocatalytic efficiency of the low-cost Ni-Co/C electrocatalyst combined with its good chemical stability and selectivity, which offer a promising route for developing an efficient lignin depolymerization technology.
研究领域:
化学工程
·
材料科学
·
环境化学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 5
·1-12
·
IF 5.3
Zhang Zejun,Shi Fan,Ai Yijing,Li Xiaoqing,Zhang Dan,Wang Lisi,Sun Wei
A core–shell ZIF-67@ZIF-8-derived Co nanoparticles embedded in N-doped carbon nanotube polyhedra (Co/C-NCNP) hybrid nanostructure was prepared by a pyrolysis method. The synthesized Co/C-NCNP was modified on the screen-printed carbon electrode and used for the portable wireless sensitive determination of breviscapine (BVC) by differential pulse voltammetry. The Co/C-NCNP had a large surface area and excellent catalytic activity with increasing Co sites to combine with BVC for selective determination, which led to the improvement of the sensitivity of the electrochemical sensor. Under optimized conditions, the constructed sensor had linear ranges from 0.15 to 20.0 µmol/L and 20.0 to 100.0 µmol/L with the limit of detection of 0.014 µmol/L (3S 0 /S). The sensor was successfully applied to BVC tablet sample analysis with satisfactory results. This work provided the potential applications of zeolitic imidazolate framework-derived nanomaterials in the fabrication of electrochemical sensors for the sensitive detection of drug samples. Graphical abstract
研究领域:
材料科学
·
分析化学
·
药物分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Functional Materials Letters
·
2019
·
IF 1.388
Lei Wei,Hongyan Liu,Qian Wang,Wenjuan Li,Lufeng Peng
Cobalt-based catalysts are highly efficient and low-cost for sodium borohydride (NaBH 4 ) hydrolysis to generate hydrogen. Co 3 O 4 and carbon-supported metal Co (i.e., Co/C) catalysts were prepared by means of ZIF-67 pyrolysis. Effects of pyrolysis temperature and atmosphere on catalyst composition and performance were mainly investigated. For material analyses, a series of characterizations were carried out including FE-SEM, TEM, XRD, BET, TGA and ICP-AES. Conventional water-displacement method was employed to evaluate the catalyst performance toward NaBH 4 hydrolysis. Experimental results indicated that catalytic activity of the Co 3 O 4 was much higher than that of Co/C, and the reasons were discussed in detail.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Lutong Li,Jiurong Liu,Fei Pan,Jing Qiao,Xue Zhang,Jingpeng Lin,Wei Liu,Qilei Wu,Shifei Tao,Fan Wu,Zhihui Zeng
Structural engineering and component design are crucial for conceiving outstanding metal-organic frameworks (MOFs)-based electromagnetic wave (EMW) absorption materials. However, an efficient and direct clarification of the structural influences on the EMW absorption performance of MOF-based absorption materials remains highly challenging and still awaits exploration. To this end, we synthesized a new type of rare earth (RE) MOFs with hexagonal-bipyramidal, snowflake-like, and dendritic structures through facilely controlling the solvent ratios in a scalable coprecipitation approach. The MOF-derived CeO 2 /Co/C hybrids with the same component content inheriting the morphological structures showcased tunable dielectric property and EMW absorption performance. The dendritic MOF derivatives with the highest anisotropy achieved a superior EMW absorption performance, manifesting a minimum reflection loss value of −71.5 dB at 1.7 mm and an effective absorption bandwidth of 5.2 GHz at 1.6 mm thickness, comparable to those of the best EMW absorbers. This work not only confirmed the high potential of RE MOF derivatives for EMW absorption, but also directly and efficiently unveiled the mechanism of morphological structure on the dielectric property and EMW absorption performance for the MOF-based EMW absorption material.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yongsong Ma,Kaifa Du,Yifan Guo,Mengyi Tang,Huayi Yin,Xuhui Mao,Dihua Wang
Greenhouse gases carbon dioxide (CO 2 ) can be converted into high value-added carbon materials by molten salt electrolysis. Herein, we employ CO 2 as the inorganic carbon source to prepare a core–shell catalyst (Co@C) by molten salt electrolysis for the activation of peroxymonosulfate (PMS) to degrade diethyl phthalate (DEP). The electrolytic Co@C catalyst presents a high catalytic performance for the degradation of DEP with a high turnover frequency (TOF) value (2.28 min −1 ), a relatively low catalyst dosage (Cat = 50 mg L –1 ), low oxidant concentration (PMS = 0.46 mM), a wide range of pH applicability (pH = 3–9), and low activation energy ( E a = 38.88 kJ mol −1 ). In addition, the Co leaching rate is low (<1 mg L –1 ) in the pH range of 5–11 and the total organic carbon (TOC) removal was reached 78.9% under the catalyst dosage was 50 mg L –1 . The DEP degradation pathways mainly involved ethyl formate elimination, ethoxy abstraction, carboxyl abstraction, decarboxylation, hydroxy abstraction, esterification and ring cleavage of DEP. Further, theoretical calculations confirm that Co nanoparticles (Co NPs) encapsulated with graphitized carbon shell derived from CO 2 reduce the work function (WF) of catalysts, enhance the length of bond O–O ( I O-O ) of PMS molecule, and facilitate the charge transfer from the catalysts to PMS molecule. This work provides a new insight into the utilization of CO 2 served as inorganic carbon sources and the design of heterogeneous catalysts.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yahui Wang,Xuandong Li,Xijiang Han,Ping Xu,Liru Cui,Honghong Zhao,Dawei Liu,Fengyuan Wang,Yunchen Du
Transition metal carbides with good chemical stability and moderate dielectric constants are becoming popular electromagnetic (EM) absorption materials. In this work, Mo 2 C/Co/C composites, a ternary loss system (conductivity loss, polarization loss, and magnetic loss) for EM absorption, have been successfully fabricated by rationally regulating the growth of ZIF-67 on the surface of MoO 3 nanorods and subsequent pyrolysis process. The chemical compositions of Mo 2 C/Co/C composites indeed play a dominant role in tailoring their EM functions. It is revealed that conductivity loss, polarization loss, and magnetic loss are together responsible for the attenuation of EM energy. Although the involvement of Mo 2 C nanoparticles weakens magnetic loss capability to some extent, there will be a positive reinforcement in conductivity loss through the synergistic effects among different components. In addition, Mo 2 C nanoparticles can further provide considerable dipole orientation polarization and interfacial polarization. Among these ternary composite, MCC-50 with 30.9% of carbon, 53.6% of Mo 2 C, and 15.5% of Co, exhibits the best EM absorption performance, whose reflection loss intensity and qualified response bandwidth are superior to those of most carbide-based composites in previous studies. These results suggest that the rational integration of components with different loss mechanisms will be an effective pathway to enhance EM absorption.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2021
·Vol. 4
·期 1
·173-185
·
IF 5.693
Xie Peitao,Liu Yuan,Feng Mei,Niu Mang,Liu Chunzhao,Wu Nannan,Sui Kunyan,Patil Rahul Rangrao,Pan Duo,Guo Zhanhu,Fan Runhua
Carbon-based composites have gained extensive attention as microwave absorbing materials due to the lighter weight compared with other materials. In this work, Co/C nanocomposites with Co nanoparticles uniformly distributed in amorphous carbon sheets are prepared by a freezing dry and carbothermic reduction process. Hierarchical porous microstructures (micropores, mesopores, macropores) are achieved by ice template and huge amounts of gas during carbothermal reduction. Excellent absorption performance is achieved at a very low Co/C content (10% and 15%), which is a great success to design ultralight absorbers. At 10% content level, the effective absorption bandwidth is 5.0 GHz with a thin thickness of 1.8 mm, while the absorption bandwidth is 4.7 GHz with a thin thickness of 1.5 mm at 15% Co/C content level. The excellent absorption performance is attributed to excellent impedance matching resulting from synergy of cobalt and carbon and strong interfacial polarization induced by the hierarchical porous microstructures. This work provides a new pathway of designing ultralight absorbers with the advantage of thin thickness and wide bandwidth. Graphical Abstract
Excellent absorption performance is achieved at only 10% Co/C content level, a success to design ultralight absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2021
·Vol. 17
·期 19
·2100082
·
IF 13.281
Jiatong Wei,Yanping Chen,Yanfu Ma,Xin Shi,Xiaoli Zhang,Chunjing Shi,Ming Hu,Jian Liu
Fischer-Tropsch synthesis (FTS) is an effective route to produce olefins, gasoline, diesel, and oxygenates from syngas (CO + H 2 ). However, it still remains a challenge for regulating the product distribution of FTS. Here, a series of Co/C sub-microreactors with precise designed nanoarchitectures are synthesized for selective syngas conversion. Through a combination of surface protection-assisted etching and following carbonization process, Co/C sub-microreactors with solid cube, double-shelled hollow box, and hollow box architectures, namely, Co/C-Cube, Co/C-DBox, Co/C-Box can be obtained. In FTS, comparing with solid Co/C-Cube, double-shelled hollow structured Co/C-DBox is inclined to grow long-chain hydrocarbon products, whereas hollow structured Co/C-Box avails the formation of short-chain hydrocarbon chemicals. Therefore, shape selective catalysis and controlled product distribution of FTS are realized by tuning the architectures of Co/C sub-microreactors. It is expected to fundamentally unravel the heterogeneous catalytic process via upfront designing and precisely regulating the architectures of micro/nanoreactors.
研究领域:
化学工程
·
材料科学
·
催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）