JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Na Li,Lihua Liu,Yi Duan,Huiling Gu,Ji Huang,Chengjun Dong,Hongtao Guan,Gang Chen
Magnetic carbon spheres are promising electromagnetic wave (EMW) absorbing materials due to their strong electromagnetic coupling effect. In the present work, magnetic carbon spheres composed of N-doped carbon spheres (NCSs) with magnetic Fe and Fe 3 C (Fe-Fe 3 C) nanoparticles were synthesized and the contents of Fe nanoparticles were adjusted through dilute hydrochloric acid treatment processes. The prepared NCSs/Fe-Fe 3 C composites dominate excellent EMW absorption performances with an optimal reflection loss value reaching − 63.77 dB at 9.92 GHz under a matching thickness of 2.9 mm, and the effective absorption bandwidth (EAB) reaches 4.88 GHz. The excellent absorption performance can be attributed to the synergistic effect of conductance loss, polarization loss, and magnetic loss arising from the different components of the composites. Moreover, the variation of Fe contents can regulate the dielectric and magnetic permeability characteristics of NCSs/Fe-Fe 3 C composites, and finally balance the impedance matching and attenuation coefficient. Our results pave the way for the development of high-efficiency EMW absorbing materials and clarify the regulation mechanism of magnetic media on the absorption performances of magnetic carbon spheres.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yuehua Pan,Yingxue Pang,Hao Fu,Zhenyu Cai,Yuxiang Deng,Zhiwei Huang,Donglou Ren,Yuezhou Wei,Xinpeng Wang
Extracting uranium from uranium waste streams, particularly utilizing zero-carbon emission photochemistry, emerges as a promising and sustainable strategy. Herein, we construct an SS@Ga/PCS composite photocatalyst, consisting of SnS 2 nanosheets as well as a metal − support produced by confining sub-nano Ga δ+ clusters in the hollow porous carbon spheres (PCS). The Ga δ+ clusters are innovatively introduced as active sites with localized hole capability to simultaneously improve visible light response and carrier separation. In-situ characterizations and theoretical calculations reveal that Ga δ+ clusters induced metal-support interaction (MSI) by optimizing the electronic structure in the PCS host; In addition, Ga δ+ clusters act as plasma excitation elements to enhance the visible light responsiveness and carrier separation of SS@Ga/PCS. Ultimately, the inhomogeneous photocatalysis of uranium extraction achieved superior performance as compared to the pure components, corresponding to an encouraging removal rate of 97.87 % and a photo-extraction capacity of up to 1867.30 mg g −1 in 50 mL of uranium waste solution, as well as a wide-concentration window adaptability and excellent catalytic robustness. More significantly, this ingenious nano-confined strategy extends the design ideas of highly dispersed sub-nanometallic cluster co-catalysts and stimulates the study of the availability of abundant reactive active sites combined with monomer strong interactions, which provides a novel insight into the mechanism of photocatalytic uranium extraction.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Xiaoxu Zhao,Ziyang Lu,Maobin Wei,Menghan Zhang,Hongjun Dong,Chengwu Yi,Rong Ji,Yongsheng Yan
Developing high-efficiency and low-cost semiconductor photocatalysts with carbon layer modification has been proved to possess the potential advantage for dramatically improved photocatalytic performance in recent years. Here, a novel magnetic core-shell Fe 3 O 4 @C modified with Co 3 O 4 nanochains photocatalyst (Fe 3 O 4 @C/Co 3 O 4 ) is first constructed via a facile synthetic strategy using inexpensive and ordinary yeast as carbon source. The obtained composite structure is conducive to the transfer and separation of charge carriers due to the synergetic effect of carbon layer and Co 3 O 4 nanochains. In consequence, the photodegradation activity of various pollutants is significantly enhanced relative to that of pure Co 3 O 4 under visible light irradiation. Moreover, the introduction of magnetic materials makes this photocatalyst recycled easily by an external magnetic field and reused effectively without obvious activity loss. This work may provide a feasibility analysis and exemplificative strategy for using simple raw materials as carbon source to observably improve universal photocatalytic activity of composite semiconductor photocatalyst.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Haijie Li,Qingshan Miao,Yali Chen,Mingyuan Yin,Hao Qi,Meichen Yang,Qiliang Deng,Shuo Wang
In this study, carbon spheres (CS) with ideal particle sizes (~700 nm) and regular morphology were prepared by extending the Stöber method followed by oxidative modification of nitric acid to obtain carbon spheres (MCS) with abundant carboxyl and nitryl functional groups. Characterisation by SEM, BET, XRD , Raman spectroscopy , FTIR, XPS, and elemental analysis confirmed that these materials possessed regular morphology, large specific surface area (636 m 2 /g for CS and 339 m 2 /g for MCS), a good degree of graphitisation and many carboxyl groups. Because of abundant functional groups, MCS showed excellent adsorption properties for cationic targets (paraquat (PQ), chrysoidine G (CG) and malachite green (MG)), where the maximum adsorption capacities for PQ, CG and MG were 134.63, 299.44 and 326.93 mg/g, respectively. Compared with the linearity of Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models and the pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion kinetics models, the adsorption models for PQ, CG and MG were best represented by the Temkin, Langmuir, and Freundlich isotherms, respectively, and the adsorption kinetics all fitted well with the Elovich model. Moreover, the good regeneration demonstrated in this study (the adsorption capacity remained at more than 80% after five cycles) makes MCS an outstanding candidate for water purification .
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
·
2021
·
IF 13.273
Zeyu Yuan,Junming Cao,Shulga Valerii,Hao Xu,Lili Wang,Wei Han
Sodium-ion batteries, as a promising alternative to the lithium-ion battery, have attracted extensive attention. However, due to the larger ion radius and higher standard reduction potential, the sodium-ion batteries still face poor cycle stability and relatively low energy density problems. In this work, a carbon sphere-supported Nb 2 CT x MXene/MoS 2 hierarchical structure has been designed and synthesized through hydrothermal and electrostatic self-assembly methods. The design strategy successfully improves the utilization efficiency of the MoS 2 carbon sphere as a support skeleton and reducing the diffusion path length of Na ions, leading to an improved specific capacity and rate performance. Moreover, Nb 2 CT x sheets also effectively inhibit the capacity attenuation caused by MoS 2 shedding, thus achieving the long cycle life of the sodium-ion battery. As a result, the carbon-supported MXene/MoS 2 anode delivers an ultrahigh reversible capacity, long cycling stability, and superior capacity retention rate. Notably, the carbon-supported MXene/MoS 2 anode can also obtain a considerable capacity of 196 mAh g −1 at a current density of 20 A g −1 . The full cell of SIBs was assembled, and the flexibility of the battery was tested. The density functional theory simulation results show that the sodium ion has a smaller diffusion barrier under this material design strategy.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2019
·
IF 5.162
Jie Zhu,Peiwen Wu,Linlin Chen,Jing He,Yingcheng Wu,Chao Wang,Yanhong Chao,Linjie Lu,Minqiang He,Wenshuai Zhu,Huaming Li
Construction of catalysts with integral structure for oxidative reaction process is an essential promotion to catalysts in industrial application. In this work, a 3D printing method was employed to prepare 3D printed spheres (3D-PSs), followed by carbonization to form 3D carbon spheres (3D-CSs). Then, a 3D-CSs supported phosphotungstic acid (HPW/3D-CSs) was prepared for deep oxidative desulfurization . Compared with traditional powder catalysts, the as-prepared catalyst is easy to be operated and separated from oil products. The supported catalyst possesses excellent catalytic performance and the removal of DBT , 4-MDBT and 4, 6-DMDBT in fuel oil, reaching ~100% of sulfur removal . The effects of various experimental parameters on desulfurization efficiency were considered to optimize reaction conditions. Moreover, the catalyst shows excellent thermal and chemical stability, with no obvious decrease in desulfurization activity after 5 cycles. GC–MS analysis indicates DBT sulfone was the solely oxidized product of DBT.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Minxian Xu,Li Chen,Weiliang Zhou,Xi Liu,Dongzhen Lu,Minglu Zhang,Zheru Shi
The demand for energy storage equipment in the information age era is becoming increasingly scarce, but manganese-based metal oxides with large potential windows and multivalent states were developed and used as high-performance electrode materials for energy storage. MnO 2 array grow on the carbon sphere as the precursor and then obtain multi-types and hierarchical of manganese metal oxides through gradient carbonization. The surface crystal phase changes with temperature, and the electrochemical performance shows obvious imparity. In addition, the carbon spheres gradually disappear with increasing temperature forming a hollow shell structure, which is conducive to sufficient contact between electrolyte and electrode material. It found that the annealing temperature can change the surface oxide morphology of MnO 2 /C, and it can know that the temperature promotes the conversion of MnO 2 to Mn 2 O 3 and Mn 3 O 4 . Based on the oxides of different crystal phases, the electrochemical properties are more distinctive due to their different structures. The rod-like nanoarray Mn 2 O 3 /C composites derived from annealing the precursors at 600 °C show high specific capacity and rate performance under a very large potential window of 0~1.2 V (show a remarkable specific capacitance of 277.0 F·g −1 at a current density of 1.0 A·g −1 ). Considering practical application, the as-assembles Mn 2 O 3 /C//Na 2 SO 4 //Mn 2 O 3 /C symmetrical supercapacitors device exhibits a maximum energy density of 80.35 Wh·kg −1 at a power density of 500 W·kg −1 , which can be applied promising storage materials for information age.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 74
·39312-39315
·
IF 3.708
Yanqing Lai,Fuhua Yang,Zhian Zhang,Shaofeng Jiang,Jie Li
Porous hollow carbon spheres (PHCSs) with high surface area and large pore volume were synthesised using a facile template method. After selenium (Se) encapsulation, Se/PHCS composite was formed. The obtained Se/PHCS composite was demonstrated as a suitable cathode material for lithium–selenium batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Xiao-Li Zhou,Pin-Jing He,Wei Peng,Fan Lü,Li-Ming Shao,Hua Zhang
Pyrolysis of plastics is a promising technique towards high-value utilization and solvent-free treatment of plastic waste. However, low product selectivity and broad product distribution may restrict the application of plastic pyrolysis. In this study, polyolefins and polystyrene (PS) were converted into methane and carbon spheres through pyrolysis under autogenic atmosphere (AAP). To elucidate the product evolution and reaction mechanism of AAP, product distributions, compositions and properties at 450–700 °C were investigated. At 450 °C, polyolefins were converted into 89.3–96.91 wt% pyrolysis oil ; PS was converted into 88.4 wt% of pyrolysis oil, 2.3 wt% of gas and 9.3 wt% of char. As the increase of temperature, the yields of methane and pyrolysis char increased significantly. At 700 °C, the yields of pyrolysis chars were as high as ~45 wt% and 74.1 wt% for polyolefins and PS, respectively, and the rest products was mainly pyrolysis gas with less than 1 wt% of pyrolysis oil. Pyrolysis chars were well carbonized spheres with diameters of 2 − 8 µm. Pyrolysis gas contained 93.83–95.74 vol% of methane, and possessed higher heating values of 35.8–36.2 MJ m −3 . The pyrolysis products with high purity and narrow distribution can be attributed to the enhancement of AAP on the secondary reactions of primary decomposition products, such as cracking, hydrogenation, aromatization and condensation .
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2017
·Vol. 312
·期 2
·187-198
·
IF 1.282
Zheng Zhiyang,Wang Youqun,Zhao Wuwei,Xiong Guoxuan,Cao Xiaohong,Dai Ying,Le Zhanggao,Yu Shenglong,Zhang Zhibin,Liu Yunhai
Hydrothermal carbon spheres (HCSs) functionalized with 4-aminoacetophenone oxime group (HCSs-oxime) were prepared by a grafting method and explored to adsorption of uranyl ions from aqueous solution. The results of FT-IR, elemental analysis and zeta potential indicate a successfully modification with oxime group. The adsorbent shows an excellent adsorption capacity (Langmuir, q
m
= 588.2 mg g −1 ) and quick adsorption kinetic (equilibrium time of approximately 60 min) at optimal pH of 6.0. The adsorptive selectivity for uranyl ions has been also great improved in present with various co-existing ions. Overall, HCSs-oxime is a potentially promising material for selective removal of uranium in the contaminated solution.
研究领域:
环境科学
·
材料科学
·
核化学
·
水污染治理
·
功能材料
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2012
·Vol. 23
·期 9
·095603
·
IF 3.979
Shaochun Tang,Sascha Vongehr,Xiangkang Meng
We report a general one-step route to place nanoparticles (NPs) of different noble metals controllably into interior or surface locations of submicron nanoporous carbon spheres (CSs). In particular, Pd and Au NPs can be easily put either inside or outside of the CSs by selecting these metals' differently charged precursor ions. Employing mixed precursor solutions, the method allows different metals to grow simultaneously yet selectively in the separate locations, thus resulting in composites with a complex layered structure, for example Pd or Au outside and Ag inside, Au or Pt outside and Pd inside, and other combinations. The synthesis is fast and needs no additional steps like a functionalization of surfaces. It crucially involves microwave heating, the power setting of which further influences the locations and sizes of the NPs especially in the interior of the amorphous carbon matrix. The three-dimensional composite structures are analyzed by transmission electron microscopy and energy dispersed x-ray spectroscopy combined with quantitative analysis by comparison with simulation. The UV–visible absorption of monometallic and layered composites is compared. The involved mechanisms leading to the selective decoration are discussed; important aspects being the charge of the precursor ions and selective microwave absorption.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Shujuan Jia,Qian Guo,Ming Shen,Qiang Gao,Kai Wang
A hydrothermal method was employed to synthesize nitrogen-doped porous carbon spheres (NPCSs), with tetraethoxysilane as the silica source, a phenolic resin , formed by the reacting 3-aminophenol with amphiphilic aliphatic aldehydes , as a carbon source and the self-assembly of imidazole cationic surfactant (1-dodecyl-3-methylimidazolium bromide) as a soft template. The effect of the carbon chain length of the fatty aldehyde on the morphology, pore parameters and electrochemical properties of the synthesized carbon nanomaterials was systematically investigated. Notably, the pyrene probe test shows that aliphatic aldehydes with different hydrophobic chain lengths are solubilized to the fence layer of the surfactant , which may increase the distance between the hydrophilic head groups of the surfactant and lead to collapsing of carbon sphere surfaces. Nonetheless, the synthesized N-doped porous carbon spheres exhibit interconnected pore structures , high surface area (1032–1040 m 2 g −1 ), large pore volume (0.82–1.30 cm 3 g −1 ), large pore size (3.73–6.32 nm) and abundant N content (5.86–6.94 at%). Moreover, Electrochemical tests in 6 M KOH demonstrated impressive electrochemical performance , with specific capacitance as high as 181 F g −1 at 1 A g −1 and an excellent rate capacity of 96% retention after 5000 cycles at 10 A g −1 .
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）