SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Yinghao Li,Wenjie Zhu,Qian Guo,Xi Wang,Liming Zhang,Xiaoya Gao,Yongming Luo
The cobalt ferrite materials (Co x Fe 3−x O 4 ) with different molar ratios of Co:Fe (1:16, 1:8, 1:4, 1:2, and 3:4) were synthesized by simple co-precipitation method, and used for catalyzing activation of peroxymonosulfate (PMS) to degrade sulfamethoxazole (SMX). The effects of catalyst dose, PMS dose, pH value, and inorganic ions on the degradation of SMX were investigated. Particularly, the degradation efficiency of SMX reached 91% within 10 min in CoFe 2 O 4 /PMS, and the removal rate of SMX achieved 81% at first 1 min. Meanwhile, the CoFe 2 O 4 /PMS reaction system exhibited excellent catalytic performance at a wide pH range from 3.00 to 11.00. The CoFe 2 O 4 catalyst could be easily magnetically separated and exhibited high stability in cycle experiments. EPR and quenching experiments showed that 1 O 2 , SO 4 − , and OH species were produced in the CoFe 2 O 4 /PMS system, especially OH and 1 O 2 played dominant roles during the degradation of SMX. The catalytic degradation mechanism of SMX in the CoFe 2 O 4 /SMX system was proposed, involving radical process and non-radical process. This work will provide a new way for the efficient treatment of wastewater especially those containing SMX compounds.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Kun Song,Rui Yang,Xiaoshuang Chen,Xin Wang,Guoli Chen,Nan Zhao
Developing electrodes with high stability and high specific capacity are two strategies to promote the application of supercapacitors. However, high specific capacity electrodes possess poor cycling stability, and good cycling performance electrode possesses low specific capacity, so it is difficult to achieve a balance. The stability of nano-sized metal oxides is reduced due to the collapse of their nanostructures during the cyclic process. Thus, the channel of electron transmission is destroyed, and the conduction of charge is not smooth. Therefore, we select electrodes with highest specific capacity and better cycling performance from many structures of CoFe 2 O 4 electrodes that are controllable designed by solvent ratio and structure-directing agent, such as chain, sphere, box, belt etc. In addition, we use an electrochemical method to coat the electrode with a layer of PEDOT to increase the conductivity and cyclic stability for practical application. Hence, the NF/CoFe 2 O 4 sphere/PEDOT as cathode indicates an outstanding specific capacity of 299.2 mAh g −1 at 1 A g −1 . The energy density is 230.4 Wh kg −1 (power density of 616 W kg −1 ). The aqueous hybrid supercapacitor shows a good cycle life, after 2000 cycles the capacity retention is 91.7%. The maximum current and self-discharge phenomena of mechanical energy charging are also studied and it is demonstrated that it has good tolerance to large current, which is suitable for mechanical energy charging.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Xinxin Long,Shengjiong Yang,Xiaojie Qiu,Dahu Ding,Chuanping Feng,Rongzhi Chen,JihuaTan,Xinming Wang,Nan Chen,Qin Lei
A facile coprecipitation-thermal method is reported to prepare spinel cobalt ferrites CoFe 2 O 4 nanoparticles (NPs) with a well-defined mesoporous dominated structure using hybrid cobalt-ion hexacyanoferrate (CoFeHCF) NPs as a template. The properties of the synthesized catalysts are evidenced by various characterization methods. And the effects of time, pH, catalyst/oxidant/BPA dosage, coexisting ions and natural organic matter (NOM) on catalytic degradation of bisphenol A (BPA) are investigated. The as-prepared CoFe 2 O 4 shows a high catalytic performance of 97% elimination for 45 μM BPA in 40 min. The excellent catalytic performance could be attributed to the large specific surface area (66.18 m 2 /g) and high content of cobalt (the atomic ratio of Fe/Co is 1.86) of CoFe 2 O 4 NPs. Slightly alkaline pH, higher catalyst dosage and anions including Cl − and CO 3 2− /HCO 3 − are favorable for BPA degradation. Especially, 81.57% mineralization of BPA could be achieved in 60 min under the optimization system. The catalytic capacity of CoFe 2 O 4 could be regenerated by simple washing and drying at 200℃, which is much lower than the crystal temperature. SO 4 ∙ − and HO∙ are the primary reactive species responsible for BPA oxidation while SO 4 ∙ − might play a dominant role. This work provides a novel method to produce CoFe 2 O 4 nanocatalysts for contaminant degradation and encourage the extended application of CoFeHCF in the environment.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Wanyi Xie,Yanzi Wang,Jie Zhou,Meng Zhang,Jiali Yu,Caizhen Zhu,Jian Xu
In this work, a MOF-derived Co-Fe oxide porous nanorod is introduced into the freestanding MXene film to produce a high-performance flexible electrode with excellent deformability and editability. The as-prepared composite film electrode demonstrates several advantages: MXene layer functions as a binder and conductive additive to coat Co-Fe oxide, which can effectively facilitate charge transfer and maintain the excellent flexibility of the film electrode. In the meantime, Co-Fe oxide can work as a spacer, thereby expanding the interlayer distance, improving the ion transmission path in the electrode. As a result, the optimal Co-Fe oxide/Ti 3 C 2 T X composite paper manifests a remarkable volumetric capacitance of 2467.6 F cm −3 in 1 M LiCl electrolyte. When assembled into a flexible symmetrical supercapacitor, an outstanding specific areal capacitance of 356.4 mF cm −2 can be obtained. Meanwhile, the flexible supercapacitor demonstrates excellent cycling performance with a high capacitance retention of 88.2% after 10 000 charge/discharge cycles, as well as stable electrochemical energy storage stability after 100 cycles of mechanical bending, indicating its great application potential in future flexible and portable energy storage equipment.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2021
·
IF 3.247
Xu Guo,Shasha Ai,Dan Yang,Lei Zhao,Hanming Ding
The integration of two different advanced oxidation processes can not only avoid their individual shortcomings but also utilize the synergistic effects between them. Herein, CoFe2O4 modified g-C3N4 composite (CoFe2O4@g-C3N4) was synthesized and used for building a novel coupled system, in which two processes of visible light-activated photocatalysis and sulfate radical-based Fenton-like oxidation have been combined together to provide a synergistic reaction path for the removal of rhodamine B. The coupled system exhibited a drastically enhanced catalytic efficiency compared with the photocatalytic or Fenton-like process alone. It also showed a significantly enhanced catalytic activity compared with g-C3N4, CoFe2O4 or their simple mixture. The improved catalytic performance can be ascribed to the efficient separation of photogenerated carriers as well as more available catalytic reactive sites for peroxymonosulfate (PMS) activation due to the synergistic effects between the photocatalytic and Fenton-like processes. In 30 min, 96% RhB was degraded using PMS activated by a CoFe2O4@g-C3N4 composite with 3% CoFe2O4 loading under visible light irradiation, and the synergistic index in such system reached as high as 3.07. Such system can be used at a wide pH range of 3.0–10.0. The composite also showed good stability for its practical applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 2
·590-597
·
IF 5.934
Xiaoqing Cui,Wei Liu,Weihua Gu,Xiaohui Liang,Guangbin Ji
In recent years, two-dimensional inorganic materials (MoS2) have been promising candidates for EM wave absorber because of their high specific surface area, excellent electronic properties and dielectric loss caused by polymorphism. Nevertheless, the poor impedance matching of individual MoS2 limited its microwave absorption performance. Optimizing the impedance matching of microwave absorber can be an effective way to achieve electromagnetic wave attenuation. In this study, we deposited CoFe2O4 magnetic nanoparticles on the surface of MoS2 nanosheets using reasonable hydrothermal reactions to optimize its poor impedance and enhance interfacial polarization. The MC-6 composite (mMoS2 : mCoFe2O4 = 6 : 1) exhibited excellent microwave absorption capability. The minimum reflection loss (RL) reached −55.3 dB at 16.24 GHz (Ku band) and the effective absorption bandwidth (<−10 dB) was measured to be 6.26 GHz (X band) with a thickness of 1.6 mm. This study confirms that optimizing impedance matching and interfacial polarization of MoS2-based composites play a key role in the microwave response. Moreover, the reasonable optimization of impedance matching enables regulation of the effective bandwidth and strong absorption intensity.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Beili Pang,Shan Lin,Yongtang Shi,Yingying Wang,Yingjie Chen,Shuai Ma,Jianguang Feng,Chunkai Zhang,Liyan Yu,Lifeng Dong
A novel nanocomposite of CoFe 2 O 4 nanoparticles with graphene nanosheet (CoFe 2 O 4 /GN) is prepared as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The size of CoFe 2 O 4 nanoparticles is about 3 nm, and the influence of CoFe 2 O 4 on the electrochemical properties of graphene is studied. The CoFe 2 O 4 nanoparticles anchored on graphene nanosheets can serve as spacers to prevent graphene aggregations and thereby provide efficient diffusion pathways and more active surface area for electrolyte molecules. Also, the CoFe 2 O 4 nanoparticles with substantial catalytic activity accelerate the reduction of triiodide. Meanwhile the graphene improves charge transfer during the catalytic process. Compared with CoFe 2 O 4 , graphene, and Pt electrodes, the CoFe 2 O 4 /GN electrode displays higher catalytic activity because of its minimal charge transfer resistance. The DSSCs fabricated with CoFe 2 O 4 /GN demonstrate an improved photoelectric conversion efficiency of 9.04% in comparison to Pt electrodes (6.54%). This study suggests that CoFe 2 O 4 /GN can replace expensive Pt electrodes for large-scale fabrication of low cost and high efficiency DSSCs.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 26
·期 1
·215-226
·
IF 2.8
Zhang Juan,Khan Muhammad Asim,Xia Mingzhu,Abdo Abdelnasir Mahmoud,Lei Wu,Liao Chuan,Wang Fengyun
A highly resourceful, eco-friendly, and recyclable magnetic adsorbent based on montmorillonite (CoFe 2 O 4 /MMT) was fabricated via a facile hydrothermal method to harvest tetracycline (TC) and ciprofloxacin (CIP) from pollutant water. The prepared adsorbent was characterized by XRD, FT-IR, SEM, and VSM methods to comprehend its structure, morphology, and magnetism. Effects of experimental parameters including solution pH, adsorption time, initial concentration, and ion strength were studied in details. The experimental adsorption data of TC and CIP fitted into pseudo-second-order kinetic model and Langmuir isotherm, respectively. The maximum adsorptions of TC and CIP could reach up to 240.91 and 224.00 mg/g. The thermodynamic study indicates that the adsorption process is spontaneous. In addition, the antibiotics can be further degraded under visible light environment and the magnetic sorbent can also be thermally regenerated.
ᅟ
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 14
·10632-10640
·
IF 3.84
Ke Zhang,Wei Zuo,Zhiyi Wang,Jian Liu,Tianrong Li,Baodui Wang,Zhengyin Yang
Recent studies have suggested that the physical and chemical properties of nanoparticles (NPs) strongly depend on local chemical composition, size, and shape. Here, we report a new precursor-mediated growth of monodisperse magnetic cobalt ferrite (CoFe2O4) NPs with controlled size and shape. CoFe2O4 NPs with near corner-grown cubic, near cubic and polyhedron shape can be successfully prepared by simply tuning the amount of iron and cobalt acetylacetonates in oleic acid. Interestingly, the product shape varies from near corner-grown cubic to starlike by only changing the reaction temperature from 320 °C to 330 °C. These CoFe2O4 NPs exhibit size and shape-dependent peroxidase-like activity towards 3,3′,5,5′-tetramethylbenzdine (TMB) in the presence of H2O2, and thus exhibited different levels of peroxidase-like activities, in the order of spherical > near corner-grown cubic > starlike > near cubic > polyhedron; this order was closely related to their particle size and crystal morphology. CoFe2O4NPs exhibited high stability in HAc–NaAc buffer (pH = 4.0) and high activity over a broad pH (2.5–6.0). Furthermore, the Michaelis constants Km value for the CoFe2O4 NPs (0.006 mM) with TMB as the substrate was lower than HRP (0.062 mM) and Fe3O4 NPs (0.010 mM). After further surface functionalization with folic acid (FA), the folate-conjugated CoFe2O4 nanoparticles allow discrimination of HeLa cells (folate receptor overexpression) from NIH-3T3 cells (without folate receptor expression). Such investigation is of great significance for peroxidase nanomimetics with enhanced activity and utilization.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 40
·33636-33642
·
IF 3.289
Zezhou Yang,Zhen Zhang,Yanzhou Jiang,Maoqiang Chi,Guangdi Nie,Xiaofeng Lu,Ce Wang
Herein, we report a simple procedure to decorate small palladium nanoparticles (Pd NPs) on the surface of CoFe2O4 nanotubes; the decorated nanotubes possess intrinsic peroxidase-like activity for the sensitive detection of H2O2. The CoFe2O4 nanotubes are prepared via an electrospinning technique, followed by a calcination process in air. The functionalization of Pd NPs on the surface of CoFe2O4 nanotubes was achieved through an in situ reduction process using ascorbic acid (AA) as a reducing agent. The synthesized Pd nanoparticles, which are small in size, are evenly dispersed on the surface of the CoFe2O4 nanotubes. The hollow structure of the CoFe2O4 nanotubes and the uniform distribution of the Pd nanoparticles enhance peroxidase-like activity toward the catalytic oxidation of the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2. The peroxidase-like property of the Pd/CoFe2O4 composite nanotubes provides a facile approach for the colorimetric detection of H2O2 with a low detection limit. This work provides great potential for Pd/CoFe2O4 nanotubes as enzyme-like nanocatalysts to sensitively detect H2O2 in biological systems.
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Water Research & Technology
·
2024
·
IF 3.5
Wei Wei,Shiqian Gao,Feiyue Qian,Chongjun Chen,Youyi Wu
Reduced graphene oxide modified CoFe2O4 (CoFe2O4/rGO) magnetic nanoparticles (MNPs) were synthesized by employing an in situ crystallization microwave irradiation method. The morphology and textural properties of CoFe2O4/rGO were characterized using SEM, TEM, BET/BJH and XPS. GO was reduced to rGO via the thermal catalysis of Co(acac)2, which contributed to expanding the effective microwave absorption bandwidth of carbon-based materials. The lattice stability of CoFe2O4 effectively improved Snoek's limit and protected the catalytic active site distribution of CoFe2O4/rGO nanoparticles. The CoFe2O4/rGO composites were selected as a heterogeneous catalyst to initiate the activation of peroxymonosulfate (PMS) for the generation of reactive oxygen species (ROS) and degrade 2-aminobenzothiazole (ABT) in a water sample. Under optimal conditions, the coupling of CoFe2O4/rGO and PMS can completely degrade ABT in aqueous solutions within 90 minutes. The effect of inorganic anions, metal cations and humic acid (HA) on the degradation efficiency of ABT was explored. Experimental results showed that the presence of HA and low concentrations of Cu2+ enhanced the process performance remarkably, while the addition of NO3−, SO42−, Zn2+, Cd2+ and high concentrations of Cu2+ suppressed the degradation of ABT. Meanwhile, the absence of Cl− and HCO3− presented no significant influence on the degradation. Radical quenching experiments indicated that SO4−·, ·OH and non-free radicals of 1O2 were involved in the CoFe2O4/rGO-PMS system, with the former two being the dominating radical species. A degradation efficiency of 100% was obtained when the proposed method was applied to the degradation of ABT in actual water samples. The CoFe2O4/rGO catalyst-activated PMS processes offered a reference to eliminate refractory organics in water.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Yanli Niu,Xiaoqin Huang,Lei Zhao,Weihua Hu,Chang Ming Li
We herein report a facile strategy to synthesize transition metal/spinel oxide nanoparticles coupled with nitrogen-doped graphene (Co/CoFe2O4@N-graphene) as an efficient bifunctional electrocatalyst toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). This approach involves a spontaneous solution-polymerization of polydopamine (PDA) film on graphene oxide (GO) sheets in the presence of Fe3+ and Co2+ to form the Fe/Co-PDA-GO precursor, followed by pyrolysis at 800 °C in argon (Ar) atmosphere. During the calcination process, Co/CoFe2O4 nanoparticles are in situ formed via high-temperature solid state reaction and are further entrapped by the PDA-derived N-doped carbon layer. As-prepared Co/CoFe2O4@N-graphene exhibits highly efficient catalytic activity and excellent stability for both ORR and OER in alkaline solution. This work reports a facile synthetic approach to develop highly active electrocatalysts while offering great flexibility to tailor their components and morphologies and thus provides a useful route to the design and synthesis of a broad variety of electrocatalysts.
✓ 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）