MACROMOLECULAR MATERIALS AND ENGINEERING
·
2013
·Vol. 299
·期 3
·361-367
·
IF 2.338
Weining Sun,Xiaofeng Lu,Yanpeng Xue,Yan Tong,Ce Wang
In this report, CoFe 2 O 4 /Polypyrrole (PPy)/Pd ternary composite nanofibers are fabricated through a one-step redox reaction between pyrrole and Na 2 PdCl 4 in the presence of electrospun CoFe 2 O 4 nanofibers in ethylene glycol (EG). The generation of Pd nanoparticles is accompanied by the formation of PPy on the surface of electrospun CoFe 2 O 4 nanofibers during the redox reaction. The as-prepared CoFe 2 O 4 /PPy/Pd composite nanofibers may be used as efficient catalysts for the p -nitrophenol hydrogenation with an apparent rate constant ( k app ) of about 13.2 × 10 −3 s −1 . The CoFe 2 O 4 /PPy/Pd composite nanofibers show good magnetic properties, which can be readily recycled under an external magnetic field.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Yichi Zhang,Jingang Zhang,Dongping Sun,Jean-Marie Basset,Jingxia Qian,Lu Zhou
This study employed nonahydrate ferric nitrate and hexahydrate cobalt nitrate as precursors to fabricate catalysts via calcination, varying the iron-cobalt molar ratios (1: 5, 3: 4, 1: 1, 4: 3, 5: 1). It identified the optimal ratio for catalytic decomposition of methane (CDM) performance. Furthermore, adjusting the calcination temperature enabled control over the spinel content in catalysts with the optimal Fe: Co ratio (3: 4), resulting in a range of single and bimetallic catalysts with diverse spinel contents. Comparative analysis revealed the superior performance of bimetallic catalysts compared to single-metal counterparts. Specifically, under the conditions of 800 °C and GHSV 6 L/(g cat. ·h), Fe 3 Co 4 -700 °C achieved a maximum methane conversion of 75.6%, after maintaining a CDM test for 6 h, there is no decrease in stability. This is because the synergistic effect of Fe and Co bimetallic in the Fe 3 Co 4 -700 °C catalyst facilitates the transfer of charges between the bimetals, alters the surface charge density of the catalyst, enhances the electron donation capability of active sites, thereby favoring the adsorption and cracking processes of methane. XRD indicates that this catalyst with smaller crystallite size benefits the dispersion of catalytic active sites, thus improving the CDM performance. Results underscored the significant impacts of calcination temperature and metal ratio on the catalyst's spinel content and crystallite size. Characterization of spent catalysts unveiled carbon products primarily comprising carbon nano-onions, graphite, and carbon nanotubes, with the optimal catalyst yielding 5.8 g C /g cat. . Increasing calcination temperatures facilitated the formation of the spinel phase. At 150 °C, the Fe: Co (3: 4) catalyst had minimal spinel content, whereas at 300 °C, 700 °C, and 1000 °C, the contents are 9%, 11%, and 24%, respectively. Notably, at 1500 °C, the spinel content dramatically surged to 62%. The relationship between spinel content and spent catalyst crystallite size is not linear, the smaller crystal size is more conducive to the dispersion of catalytic active sites, thereby improving the CDM performance. Catalysts without spinel doping exhibited a crystallite size of around 32.2 nm, which decreased to 25.6 nm with 11% spinel content, and increased to 42.7 nm with 62% content. These findings yield profound insights into the influence of calcination temperature and iron cobalt ratios on catalyst performance, providing valuable guidance for the production of efficient CDM catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2015
·
IF 2.259
Gang Jian,Fang Meng,Dongxiang Zhou,Qiuyun Fu,Zhili Du,Chao Yan
A textured CoFe 2 O 4 ceramic was fabricated by reactive template grain growth (RTGG) method using rod-like α-FeOOH particles as templates. The template particles were synthesized by hydrothermal method , the particles showed good crystallization and rod-like shape with a diameter of 0.1–0.2 μm and an aspect ratio of 20–50. { ll0 } oriented CoFe 2 O 4 ceramic was obtained after a sintering process. The ceramic sintered at 1150 °C for 4 h showed dense and oriented structure with orientation degree of 0.89. Different magnetic hysteresis loops were observed along the in-plane and out-of-plane direction of the textured CoFe 2 O 4 , which was due to anisotropy properties of the sample. The textured ceramic exhibited an in-plane M s enhancement (355 emu/cm 3 ) compared to that of the non-textured ceramics (320 emu/cm 3 ) in the same sintering conditions.
研究领域:
材料科学
·
磁性材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Pengfei Yin,Yuting Tang,Limin Zhang,Sihan Liu,Jian Wang,Yi Zhang,Xiyuan Sun,Zhihua Gao,Haipeng Hu,Yongpeng Zhao
Preparation of microwave absorption materials is one of the most effective way to solve hazards of excessive microwave radiation at current stage. Herein, a series of pyramid-like carbon frameworks embedded with Co 3 Fe 7 and CoFe 2 O 4 phases have been synthesized via a solvent-controlled strategy in solvothermal-annealing process. The solvent ratio of DMF and DW has great impact on the morphology and electromagnetic wave dissipation properties of such composites. The composite can reach the maximal RL of −24.66 dB at 7.68 GHz and the optimal EAB of 6.3 GHz for only 2.62 mm, this realization of wider EAB at thin thickness is due to the synergic effect of dielectric polarization, magnetic resonance, structural damping and so on. Most important of all, the wide range of appropriate impedance matching in as-prepared composite is the first premise. The broad EAB of composite prepared here reveals its prospect for actual application in protection of microwave radiation.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2024
·
IF 4.3
Yuqi Cao,Yingpei Liu,Chenchen Ding,Tingting Ma,Huimin Ye,Weiwei Zhong,Wei He
In this study, four cobalt ferrite@carbon nitride (CoFe 2 O 4 @g-C 3 N 4 ) composites were prepared by co-precipitation method to achieve chemo-photodynamic synergistic cancer therapy. The effect of the morphology of g-C 3 N 4 on the chemotherapy and photodynamic therapy of CoFe 2 O 4 @g-C 3 N 4 (CFO@g-C 3 N 4 ) was investigated in detail. CFO@PMCN with porous structures and CFO@CNT with a reticulated structure displayed high loading efficiencies of doxorubicin (DOX), exhibiting a pH-responsive release property and facilitating the delivery of DOX into cancer cells for chemotherapy. CFO@CNT possessed a higher photothermal performance for photothermal agents in cancer treatment compared with other CoFe 2 O 4 @g-C 3 N 4 composites. In addition, more reactive oxygen species (ROS) was generated in the assistance of CFO@CNT under the irradiation condition for photodynamic therapy (PDT) treatment. Based on the synergistic effect of chemotherapy and photodynamic therapy, the obtained CFO@CNT-DOX exhibited an excellent therapeutic effect and significant pH-responsive release characteristics confirmed by dimethylthiazol diphenyltetrazolium bromide (MTT) assay and dual staining fluorescence imaging analysis.
研究领域:
纳米医学
·
肿瘤学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Danqiang Huang,Jianfeng Dai,Qing Wang,Hui Liu,Zengpeng Li
A multi-component, special structure of electromagnetic wave absorber produces significant electromagnetic wave absorption performance because of excellent impedance matching. In this work, CoFe 2 O 4 @CNTs composites are prepared. CoFe 2 O 4 exhibits a hollow and open-hole shape with a rough surface, and this structure facilitates more electromagnetic wave absorption. The incorporation of multiwalled carbon nanotubes (MWCNTs) leads to dipole polarization and when wrapped around CoFe 2 O 4 particles, increases the interface loss. The influence of the filler-loading ratio on the microwave absorption performance of wax-based absorbers is thoroughly investigated. The highest electromagnetic wave absorption performance is obtained at 25% filling with a minimum reflection loss (RL min ) of − 36.52 dB at a thickness of 1.9 mm and effective absorption bandwidth (EAB) is 3 GHz. In this study, a method is proposed for creating high-performance electromagnetic wave 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
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Yu Feng,Yu Zhang,Jie Sheng,Tiandong Zhang,Qingguo Chi,Qingguo Chen,Weidong Fei
Multiferroic materials have good application prospect in the field of non-volatile random access memory due to the simultaneous existence of ferroelectricity, ferromagnetism, and the coupling between them. In this work, two kinds of nanofibers (pure CoFe2O4 nanofibers and CoFe2O4 nanofibers coated with a BaTiO3 layer) were designed and fabricated. P(VDF-TrFE)-based composites with aligned nanofibers were prepared via high-speed directional electrospinning. The effect of ferromagnetic nanofibers on the ferroelectricity of composites was investigated, and the multiferroic performance and magnetic anisotropy were observed. The leakage current of the composite can be well suppressed after coating the BaTiO3 layer, and it makes the composite possess enhanced ferroelectric and ferromagnetic properties at the same time. Notably, the maximum polarization and remnant polarization of a 10 vol % P(VDF-TrFE)/CoFe2O4@BaTiO3 composite reach 8.0 and 7.0 μC/cm2, respectively, when the applied electric field is 1000 kV/cm. Meanwhile, the maximum magnetization and remnant magnetization are 5.9 and 2.0 emu/g at 20,000 Oe, respectively, and the magnetization along the nanofiber direction is larger than that perpendicular to the nanofiber direction on the surface of the composites. The maximum values of the magnetoelectric voltage coefficient reached 5111 mV/cm·Oe (Hdc = 8083 Oe) for the 5 vol % P(VDF-TrFE)/CoFe2O4@BaTiO3 composite. The excellent ferroelectric and ferromagnetic properties in a high electric field make flexible composites promising to be an ideal material for improving the multiferroic devices.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
INTEGRATED FERROELECTRICS
·
2020
·
IF 0.557
Zhennan Liu,Chunsheng Shi,Fang He,Naiqin Zhao
A novel electromagnetic wave absorber of three-dimensional carbon networks decorated with CoFe2O4 nanoparticles (3DC/CoFe2O4) was prepared through a simple freeze-drying method followed by a high-temperature calcination process. The 3DC/CoFe2O4 composite prepared at 630 °C (S630) exhibits broadband electromagnetic wave absorption with only 20 wt% filler loading. The effective absorption bandwidth (reflection loss [RL] < −10 dB) of S630 reaches up 6.63 GHz, and the minimum RL of −19.5 dB is obtained at 15.45 GHz when the matching thickness is 2.5 mm. The excellent electromagnetic wave absorption performance of the 3DC/CoFe2O4 composite can be attributed to good impedance matching and strong attenuation capacity.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zhenze Xie,Yucheng Huang,Jingguang Wang,Wenxin Guo,Yutao Lin,Yingxin Lin,Chang Du
Breast cancer is one of the most widespread cancers worldwide in the female population. However, the side effects and toxicity of chemotherapy and radiotherapy are the obstacles to the treatment of breast cancer. Therefore, we developed a Pt loaded CoFe 2 O 4 -based nanoparticles (CF@Pt) for breast cancer treatment with chemodynamic therapy (CDT) and sonodynamic therapy (SDT). The Co 2+ /Co 3+ and Fe 2+ /Fe 3+ gave CF@Pt peroxidase-like activity and catalase activity to gain ·OH and O 2 in the tumor microenvironment (TME) for CDT. Furthermore, the separation of electron-hole pairs of CF@Pt transferred the O 2 into 1 O 2 in the presence of ultrasound (US) for SDT. The high level of O 2 generated by CDT would produce more 1 O 2 by SDT that promoted the CDT efficiency. Moreover, the addition of Pt limited the recombination of electron-hole pairs and reduced the energy gap to enhance SDT/CDT combination therapy. In addition, CF@Pt could be engulfed by MDA-MB-231 cells and induced the apoptosis while it had good biocompatibility and blood compatibility. This design provided a novel application on the treatment of breast cancer.
研究领域:
肿瘤学
·
纳米医学
·
生物材料学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 48
·e54722
·
IF 3
Jingxiang Wang,Min Li,Xunwei Liu,Jiangmin Yu,Dicheng Yang,Chunping Yuan,Xiaoying Yin,Yinan Yan
Magnetic hyperthermia generated by functionalized bone cement is a promising approach to treat postosteocarcinoma cancer regeneration. However, it is crucial to minimize the magnetic field intensity using localized high-caloric-generating nanoparticles to avoid the potential hazards of electromagnetic field exposure to living organisms. Herein, in situ hydrothermally synthesized CoFe 2 O 4 (CoFe) nanoparticles and boron nitride nanosheet (BNNS)–supported CoFe complexes (BNCoFe) are incorporated into polymethyl methacrylate (PMMA) cement to prepare a composite implant with high-intensity magnetic–thermal performance and safety. The results show that the CoFe nanoparticles (size = ~70 nm) anchored on BNNS surfaces exhibit a maximum magnetic–thermal ablation temperature of ~42°C within 50 s under an alternating magnetic field of 400 KHz (field frequency) and 30 Oe (field intensity) in vitro. Furthermore, the incorporation of BNNSs into the PMMA matrix notably increases the thermal conductivity of PMMA from 0.07 to 0.25 W mK −1 and improves its mechanical properties (compressive strength increases from 74.0 ± 1.6 to 81.0 ± 1.0 MPa), which is attributed to the crystalline structure of BNNSs in the PMMA matrix. Inductively coupled plasma analysis shows a considerably reduced Co 2+ ion release from PMMA/BNCoFe, indicating its potential as a safe implantation material for hyperthermia treatment.
研究领域:
生物医学工程
·
材料科学
·
肿瘤治疗
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2025
·
IF 3.3
Fangjie Liu,Zhengqi Su,Haizhao Li,Qingjie Wang,Xin Wang,Weiwei Shang,Bin Xu
CoFe 2 O 4 (CFO) was identified as one of the potential cathode materials for solid oxide fuel cells (SOFCs). However, optimization was required due to limitations of electrochemical performance. Here effects of Ca doping on CFO were investigated for the oxygen reduction reaction (ORR) properties. Co 1-x Ca x Fe 2 O 4 (CCxFO, x = 0, 0.2 (CC2FO), 0.4 (CC4FO)) were synthesized with sol-gel method. Oxygen vacancy concentration was increased by Ca doping enhancing the electrochemical performance of CFO. At 750 °C, the polarization resistance (R p ) of CC4FO was 1.04 Ω·cm 2 , which was 1.09 Ω·cm 2 lower than that of CFO (2.13 Ω·cm 2 ). The electronic conductivity value (σ) of CC4FO was 0.614 at 750 °C and the activation energy (E a ) of CC4FO was 102.81 kJ/mol. The results indicated that improvements in the ORR activity of the CFO spinel material were mainly attributed to an increase in oxygen vacancy concentration and oxygen surface exchange rate due to Ca doping, CC4FO showed promising potential as SOFC cathode.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2021
·Vol. 30
·期 8
·085014
·
IF 3.585
Zhenji Zhou,Caiyin You,Feng Li,Na Tian,Yao Chen,Qian Chen
Various additives in smart materials are attracting wide attention owing to the improved adaptable functions, such as the ferromagnetic additive. However, the effect of additives' morphology is not well investigated, causing inconsistent phenomena reported for the same additive. In this work, the spherical and rod-shaped CoFe2O4 nanoparticles were prepared by varying the reaction process of solvothermal, and introduced as dispersed phases into strain rate-sensitive materials to fabricate new strain-rate sensitive composite materials. The influence of magnetic particle morphology on its rheological performance was investigated. The results showed that the strain-rate sensitive composites with rod-shaped CoFe2O4 (RCFO) have a higher storage modulus and viscosity than the ones with spherical CoFe2O4 (SCFO) nanoparticles. The relationship between shear rate and viscosity indicates that all samples exhibited significant shear thinning effects in the range of shear rates studied, and the RCFO nanoparticles are useful for achieving a higher viscosity in comparison to the SCFO nanoparticles at the same shear rate. This work proves that the morphology of additives plays an important role in adjusting the property of smart materials and is expected to present some principles to choose the suitable morphology of additives for the design of new magneto-rheological materials.
研究领域:
材料科学
·
纳米技术
·
复合材料
✓ 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）