POLYMER
·
2020
·
IF 4.231
Zhenguo Gao,Jiaoqiang Zhang,Shijie Zhang,Di Lan,Zehao Zhao,Kaichang Kou
Given the remarkable performances of metal frame works (MOFs) and ferrocene containing polymers (FCPs) in electronic devices, the research on integration of structure and function for collaborative optimization of electromagnetic wave (EMW) absorption are still missing. Herein, surface grafting and main chain polymerization methods have been employed on the FCPs modifying zeolitic imidazolate framework-67 (ZIF-67) respectively. Polydopamine-coated ZIF-67 was precursor for grafting type products (ZIF-67@PDA-Fc), while poly (vinyl ferrocene) was for main-chain type products (ZIF-67@PVF). Furthermore, the calcined products, polyhedron capsules structured Co 3 O 4 @C@α-Fe 2 O 3 and Co 3 O 4 /α-Fe 2 O 3 @C microwave absorbers were obtained from ZIF-67@PDA-Fc and ZIF-67@PVF for higher performance EMW absorption. The crystal, morphological and chemical structure was detected via XRD , SEM, TEM, FTIR, Raman, XPS techniques. The EMW absorbability was calculated according to transmission line theory. In particular, the minimum reflection loss (RL min ) of Co 3 O 4 @C@α-Fe 2 O 3 reached −52.2 dB at the thickness of 3.7 mm with effective absorption band ( f E ) 4.4 GHz. It is worth emphasized that the broadest f E was 6.6 GHz obtained at 2.5 mm with RL min reaching −38.4 dB. Additionally, the EMW absorption mechanism was also studied based on the dielectric and magnetic properties . This investigation will push forward further research and practical application of metal organic compounds-based composites.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Ming Zhang,Zhonglin Chen,Jingqi Ruan,Weizhen Shao,Wenxian Wei,He Guo,Zhanghao Chen,Weichuan Qiao
Confined catalytic provides a novel approach to achieve efficient removal of pollutants, however, the tedious preparation process and lower catalytic activity of catalysts are the main restrict for their widespread use. Here, the in-situ doping and reaction kinetics regulation strategy have been proposed to prepare yolk-shell Fe 3 O 4 /Co 3 O 4 /C@SiO 2 nanoreactors (YSFNs) for plasma-catalytic degradation of organic pollutant. In the preparation process, on the one hand Fe(acac) 3 was in-suit doped into ZIF-67, on the other hand the nucleation/growth rate of ZIF-67 is faster than the hydrolysis/polycondensation rate of tetraethyl silicate (TEOS), and thus generated Fe/ZIF-67@SiO 2 precursor. To present the advantages of YSFNs, dielectric barrier discharge (DBD) plasma for tetracycline (TTCH) degradation was chosen as the model reaction. The results indicate that YSFNs-2 display excellent TTCH degradation performance over only DBD, YSCNs-1/2/3 and Fe 3 O 4 /Co 3 O 4 /C nanoparticles (FNs). The enhanced catalytic performance is ascribed to two aspects: (i) confinement effect of yolk-shell structure improves the utilization rate of active species (structure advantage); (ii) graphitized carbon increases electrical conductively while dispersing the active sites, and thus improves the reaction kinetics (composition advantage). This work indicates that MOFs-derived catalysts with confined catalytic have a promising application prospect for environmental remediation via DBD plasma.
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
ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 33
·1902875
·
IF 15.621
Zhichao Wang,Wenjia Xu,Xiaokang Chen,Yanhua Peng,Yanyan Song,Chunxiao Lv,Hongli Liu,Junwei Sun,Ding Yuan,Xiyan Li,Xiangxin Guo,Dongjiang Yang,Lixue Zhang
Heteroatom doping plays a significant role in optimizing the catalytic performance of electrocatalysts. However, research on heteroatom doped electrocatalysts with abundant defects and well-defined morphology remain a great challenge. Herein, a class of defect-engineered nitrogen-doped Co 3 O 4 nanoparticles/nitrogen-doped carbon framework (N-Co 3 O 4 @NC) strongly coupled porous nanocubes, made using a zeolitic imidazolate framework-67 via a controllable N-doping strategy, is demonstrated for achieving remarkable oxygen evolution reaction (OER) catalysis. X-ray photoelectron spectroscopy, X-ray absorption fine structure, and electron spin resonance results clearly reveal the formation of a considerable amount of nitrogen dopants and oxygen vacancies in N-Co 3 O 4 @NC. The defect engineering of N-Co 3 O 4 @NC makes it exhibit an overpotential of only 266 mV to reach 10 mA cm −2 , a low Tafel slope of 54.9 mV dec −1 and superior catalytic stability for OER, which is comparable to that of commercial RuO 2 . Density functional theory calculations indicate N-doping could promote catalytic activity via improving electronic conductivity, accelerating reaction kinetics, and optimizing the adsorption energy for intermediates of OER. Interestingly, N-Co 3 O 4 @NC also shows a superior oxygen reduction reaction activity, making it a bifunctional electrocatalyst for zinc–air batteries. The zinc–air battery with the N-Co 3 O 4 @NC cathode demonstrates superior efficiency and durability, showing the feasibility of N-Co 3 O 4 /NC in electrochemical energy devices.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Ahmed Zaki Alhakemy,Nangan Senthilkumar,Yichun Ding,Junwei Li,Zhenhai Wen
Exploring low-cost, highly efficient, and sustainable non-precious electrocatalysts for electrolytic H 2 generation is driving research for the sustainable green urban development. Herein, we present a simple synthetic approach, through a two-step process, to prepare the bifunctional electrode of Co 3 O 4 –C@FeMoP hybrid micro rods/nanosheets anchored on nickel foam (NF), in which the Co 3 O 4 –C microrods grown on NF surface are decorated by FeMoP nanosheet layers, which is directly grown through a simple hydrothermal followed by post-phosphorization processes. The obtained hybrid hierarchical Co 3 O 4 –C@FeMoP/NF shows a significant enhancement in the electrocatalytic activities of oxygen/hydrogen evolution reactions (OER/HER) in comparison to the individual Co 3 O 4 –C and FeMoP nanostructures , thanks to more heterointerface active sites provided by FeMoP nanostructures with three-dimensional (3-D) layered architectures. The Co 3 O 4 –C@FeMoP/NF catalyst exhibits a relatively small overpotential of 200 mV vs. RHE for OER to achieve 20 mA/cm 2 and 123 mV vs RHE at 10 mA/cm 2 for HER along with excellent durability in alkaline electrolytes . We demonstrate the bifunctional electrocatalytic electrode as the electrolyzer for the generation of H 2 via water splitting at small applied voltage of 1.61 V to achieve 10 mA/cm 2 and good stability for 24-h continuous running.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
SYNTHETIC METALS
·
2017
·
IF 2.435
Binghu Wang,Wensheng Tan,Renjun Fu,Huihui Mao,Yong Kong,Yong Qin,Yongxin Tao
Hierarchical mesoporous Co 3 O 4 /C@MoS 2 core-shell structured materials are synthesized via a two-step calcination and a solvothermal method using cobalt metal-organic frameworks (cobalt-MOFs, ZIF-67) and (NH 4 ) 2 MoS 4 as the precursors of Co 3 O 4 /C and MoS 2 , respectively, which is a new class of core-shell materials as supercapacitor electrode materials. The obtained Co 3 O 4 /C@MoS 2 exhibits high specific capacitance (1076 F g −1 at 1 A g −1 ), rate capability (76.9% capacitance retention at 10 A g −1 ) and cyclic stability (64.5% capacitance retention after 5000 cycles at 10 A g −1 ). Moreover, the content of MoS 2 greatly influences the electrochemical performances of the obtained core-shell materials. The results demonstrate that the as-synthesized ZIF-67 can be used as a promising candidate for designing Co 3 O 4 based core-shell materials used in supercapacitors.
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
Nano Energy
·
2020
·
IF 16.602
Baoyu Sun,Shuaifeng Lou,Wei Zheng,Zhengyi Qian,Can Cui,Pengjian Zuo,Chunyu Du,Jingying Xie,Jiajun Wang,Geping Yin
Constructing robust 2D−based energy storage nanomaterials by well−defined pore architectures and rational surface modification are critical yet daunting challenges for rechargeable alkali−ion batteries. Herein, a new−type 2D interwoven multi pores decorated Co 3 O 4 @N−doped carbon nanosheet with rich surface defects is proposed as lithium/sodium ion anodes for the first time. The combining experimental researches, microscopic structure characterization and dynamics analysis demonstrate that the multi porous structure provides large numbers of channels to accelerate Li + /Na + transport, rational surface design creates abundant active sites for fast ions reactions, while robust carbon shell offers excellent ionic/electrical conductivity and structural integrity. The obtained bifunctional composites deliver superior rate performance and long−term cycle stability (~529 mA h g −1 after 2000 cycles in LIBs and ~166 mA h g −1 after 1700 cycles in SIBs) due to the synergistic contribution of the unique structure and surface defects . Furthermore, it still remains a high reversible capacity (>610 mA h g −1 after 1000 cycles) in full cell. Kinetic analysis reveals the designed anode exhibits prominent pseudocapacitive behavior, enabling ultra−fast lithium/sodium storage and ultrahigh−rate capability. This work offers valuable insights for developing high performance energy storage devices.
研究领域:
材料科学
·
电化学
·
纳米能源
·
储能技术
·
无机功能材料
·
先进电池
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Mingjia Han,Muwu Li,Xin Wu,Jianhuang Zeng,Shijun Liao
Motivated by addressing the support corrosion or stability issue for electro-catalysts, a carbon composite support has been prepared by wet-impregnation of nano-sized TiO 2 and cobalt (II) acetate tetrahydrate together with XC-72 carbon black, followed by thermal treatment at 900 °C in a reductive atmosphere. Decomposition of cobalt acetate under thermal treatment yields TiO 2 -Co 3 O 4 -C composite support (CS), as is confirmed by X-ray diffraction analysis. The composite support is found to be more corrosion resistant and stable in acidic solution than that of the conventionally used carbon black, as is witnessed by the chronoamperometric response. This composite support is then used to load 40.3 wt.% Pt nanoparticles (Pt/CS) as an electro-catalyst for proton exchange membrane fuel cells. It is found that 27.9% of the electrochemical surface area (ECSA) retained in an accelerated stability test (AST) in 0.5 M H 2 SO 4 for Pt/CS, compared with 8.4% for 39.5 wt.% Pt catalyst supported on XC-72 carbon black. The TEM image after AST for Pt/CS also confirms its improved resistance to agglomeration. The Pt/CS catalyst shows higher mass-normalized activity for methanol oxidation in 0.5 M CH 3 OH + 0.5 M H 2 SO 4 and a slower activity decay relative to that of the benchmarked Pt catalyst on carbon.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2013
·Vol. 5
·期 16
·7564-7571
·
IF 6.233
Jie Sun,Haimei Liu,Xu Chen,David G. Evans,Wensheng Yang
Superposed cobalt(II)–cobalt(III) layered double hydroxide (CoII–CoIII-LDH) nanoplates were synthesized by an oil droplet template method, in which the main steps are as follows: LDH nanosheets were first assembled on an oil droplet template to form a multishell sphere, and then the oil droplet was easily removed under centrifugal force due to its very different density from that of the assembled LDH shell. This resulted in the multishell spheres being split open to create superposed LDH nanoplates. The resulting material has a three-stage architecture, namely, the primary building blocks of nanosheets, the secondary architecture of shells derived from the nanosheets, and the long-range architecture of superposed nanoplates assembled from the vertically stacked shells. Most importantly, the as-fabricated LDH-based hierarchical structure can be readily converted to a Co3O4/C composite via calcination, without obvious structural alteration, where the residual surfactant is the source of the carbon. When used as an anode material for Li-ion batteries, the Co3O4/C electrode exhibits an excellent electrochemical performance, which is attributed to the unique hierarchically porous structure.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 17
·10634-10645
·
IF 4.036
Wenhao Jiang,Junli Wang,Xuanbing Wang,Jiang Liao,Jinlong Wei,Ruidong Xu,Linjing Yang
The conventional Pb–Ag alloy possesses a high oxygen evolution reaction overpotential, poor stability, and short service life in acidic solutions, making it an unsuitable sort of anode material for the zinc electrowinning process. Therefore, a layered carbon-covered cobalt tetroxide (Co3O4@C)-reinforced PbO2-coated electrode is fabricated via a facile two-step pyrolysis-oxidation and subsequent electrodeposition process. As a result, the reinforced PbO2-coated electrode exhibits a low OER overpotential of 517 mV at 500 A m−2 and a Tafel slope of 0.152 V per decade in a zinc electrowinning simulation solution (0.3 M ZnSO4 and 1.53 M H2SO4). The reduced overpotential of 431 mV at 500 A m−2 compared to traditional Pb–0.76%Ag alloy leads to improved energy savings, which is attributable to the presence of Co3O4@C to refine the grain size and thus increase the effective contact area. Moreover, the reinforced PbO2-coated electrode has a prolonged service life of 93 h at 20 000 A m−2 in 1.53 M H2SO4. Therefore, an accessible and efficient strategy for preparing a coated electrode to improve OER performance for zinc electrowinning is presented in this research.
研究领域:
材料科学
·
电化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Ningning Xing,Yangsai Lyu,Jia Li,Dickon H.L. Ng,Xiaolei Zhang,Weilin Zhao
Micro/nanomotors that combine the miniaturization and autonomous motion have attracted much research interest for environmental monitoring and water remediation . However, it is still challenging to develop a facile route to produce bifunctional micromotors that can simultaneously detect and remove organic pollutants from water. Herein, we developed a novel Janus micromotor with robust peroxide-like activity for simultaneously colorimetric detection and removal of catechol from water. Such laccase (Lac) functionalized Janus micromotor consisted of calcined MgAl-layered double hydroxides (MgAl-CLDHs) nanosheets and Co 3 O 4 -C nanoparticles (Lac-MgAl-CLDHs/Co 3 O 4 -C), revealing unique 3D hierarchical microstructure with highly exposed active sites. The obtained Janus micromotors exhibited autonomous motion with a maximum velocity of 171.83 ± 4.07 µm/s in the presence of 7 wt% H 2 O 2 via a chemical propulsion mechanism based on the decomposition of H 2 O 2 by Co 3 O 4 -C layer on the hemisphere surface of Janus micromotors. Owing to the combination of autonomous motion and high peroxide-like activity, Lac-MgAl-CLDHs/Co 3 O 4 -C Janus micromotors could sensitively detect catechol with the limit of detection of 0.24 μM. In addition, such Janus micromotors also could quickly degrade catechol by •OH generated from a Fenton-like reaction. It is a first step towards using autonomous micromotors for highly selective, sensitive, and facile detection and quick removal of catechol from water.
研究领域:
环境科学
·
纳米技术
·
分析化学
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Mengfan Cao,Yanjiao Zou,Yuanyuan Zhang,Ting Zeng,Qijin Wan,Guosong Lai,Nianjun Yang
Here we present a facile, rapid and reliable electrochemical sensor for quantitative analysis of hazardous photographic developing agents, including metol (MT), hydroquinone (HQ) and catechol (CC). They have been identified as usual contaminants in environment and water samples. This sensor is based on a nanocomposite of three-dimensional (3D) porous flower-like Co 3 O 4 @C hybrid and graphene nanoplates (Co 3 O 4 @C/GNP). The Co 3 O 4 @C/GNP compoiste is prepared by a two-steps procedure, consisting of the composite synthesis of a Co-MOF precursor and GNPs in the first step and subsequently direct calcination process in the N 2 atmosphere. The morphology, composition, and electrochemical behavior of the Co 3 O 4 @C/GNP composite is characterized by using microscopic methods and electrochemical techniques, revealing its 3D porous structure, abundant pores, a large electrode active area, a high conductivity, outstanding electrocatalytic and sensing performance toward MT, HQ, and CC. Taking advantages of a huge electroactive surface area and a fast electron transfer rate of GNPs and strong electrical catalytic ability of the Co 3 O 4 @C hybrid, the fabricated Co 3 O 4 @C/GNP sensor displays high sensitivity for quantitative analysis of MT, HQ and CC. Their detection limits are as low as 5.1, 14.7 and 169 nM (S/ N = 3), respectively. Beyond that, the proposed Co 3 O 4 @C/GNP electrochemical sensor shows strong reproducibility, good stability and selectivity in the voltammetric quantitation of these analytes. It has been also successfully applied in measuring these photographic developing agents in water environment. Consequently, the fabricated Co 3 O 4 @C/GNP composite is expected to be an excellent electrode material in the applications of electrochemical sensing.
研究领域:
环境科学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2020
·
IF 7.864
Jia Xie,Zhipeng Liao,Ming Zhang,Linhan Ni,Junwen Qi,Chaohai Wang,Xiuyun Sun,Lianjun Wang,Shaobin Wang,Jiansheng Li
Clean water production calls for highly efficient and less energy-intensive technologies. Herein, a novel concept of a sequential ultrafiltration-catalysis membrane is developed by loading Co3O4/C@SiO2 yolk–shell nanoreactors into the fingerlike channels of a polymeric ultrafiltration membrane. Such a sequenced structure design successfully integrates selective separation with peroxymonosulfate-based catalysis to prepare a functionalized molecular sieve membrane, which exhibits excellent decontamination performance toward multipollutants by filtering the water matrices containing humic acid (HA) and bisphenol A (BPA). In this study, 100% rejection of HA and 95% catalytic degradation of BPA were achieved under a low pressure of 0.14 MPa and an ultrahigh flux of 229 L m–2 h–1, corresponding to a retention time of 3.1 s. Notably, the removal performance of multiple pollutants essentially depends on the ordered arrangement of ultrafiltration and catalysis. Moreover, the flow-through process demonstrated significant enhancement of BPA degradation kinetics, which is 21.9 times higher than that of a conventional batch reactor. This study provides a novel strategy for excellent removal of multiple pollutants in water.
研究领域:
环境科学
·
化学工程
·
材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）