铁系氧化物纳米晶粉/环氧树脂杂化材料的制备

采用硬脂酸凝胶法制备铁系氧化物Ba2Co2Fe2sO46纳米晶粉,并通过表征和制备机理的探讨,确定600℃、2h后处理为制备Ba2Co2Fe28O46纳米晶粉合适的条件.以此为基础制备铁系氧化物纳米晶粉/环氧树脂杂化材料,并研究了团聚现象对吸波性能的影响.     

铁氧化物纳米晶自组装空心微球的制备、表征及其应用

铁氧化物纳米材料和纳米结构空心微球分别代表了材料研究中组分和结构的研究热点. 而由铁氧化物纳米晶自组装形成的空心微球的研究则是二者相结合, 具有重要的科学意义和良好的应用前景. 虽然已发展了多种方法制备各种单质及化合物的空心微球, 但铁氧化物纳米晶自组装空心微球的制备方法报道较少. 本文简要介绍了近几年发展起来的多种铁氧化物纳米晶自组装空心微球的一些制备方法, 利用上述方法, 制备出了多种不同组成单元、不同尺寸、不同空心程度的铁氧化物纳米晶自组装空心微球, 对所制备的铁氧化物纳米晶自组装空心微球进行了表征, 并初步介绍了所制备的铁氧化物纳米晶自组装空心微球在药物缓释和环境领域中的应用.     

用水解法制备水铁矿纳米团簇

提出了使用CuO增强Fe(NO_3)_3溶液水解制备水铁矿(Fe_5O_7(OH)·4H_2O)纳米团簇的方法。将适量的CuO粉末加入到沸腾的Fe(NO_3)_3溶液中,将发生沉淀反应生成纳米尺寸的铁氧化物。用X射线衍射仪、透射电子显微镜、振动样品磁强计、X射线能谱仪、X射线光电子能谱分别对沉淀生成的产物的形态和大小、磁化强度、晶体结构和化学组成进行表征。产物是由大小约6.13nm的微粒聚集形成的弱磁水铁矿纳米团簇。纳米团簇表面吸附有少量Fe(NO_3)_3,大小约为40nm。本文提出了一种通过增强水解制备纳米尺寸氧化物的新方法。     

钒钛铁精矿碳热还原制备铁基摩擦材料的热力学分析

利用钒钛铁精矿中的铁和钛元素,以钒钛铁精矿、石墨为主要原料,按铁基摩擦材料的成分添加其他组份,采用原位合成技术,实现合成与烧结一体化,制备铁基摩擦材料。对钒钛铁精矿还原过程中的热力学进行计算和分析,利用TG–DSC检测方法对还原过程中的质量变化进行分析。结果表明:当温度高于979 K时,钒钛铁精矿中Fe氧化物和Ti氧化物相继发生还原反应,其还原过程为:首先Fe3O4被还原,其次是钛磁铁矿和钛铁矿发生反应生成Fe和Ti的氧化物,最后是Ti的各阶氧化物反应生成TiC。本实验根据分析结果,制定了合理的工艺路线,获得了组织致密,结合优良的铁基摩擦材料。     

球磨时间对制备Fe-ZnO核壳纳米复合粒子的结构和性能的影响

通过高能球磨法制备了具有蛋糕-果仁形态的Fe-ZnO核壳纳米复合粒子,并研究了形成产物的微观结构、演化过程以及静磁性能和2-18GHz微波电磁参数.研究结果表明Fe-ZnO粒子具有良好的抗氧化性.XRD、HRTEM和SEM显示,随球磨进行Fe-ZnO粒子中Fe晶粒尺寸减小到10nm左右并逐渐增加表面各向异性.与微米羰基铁相比,Fe-ZnO粒子具有较大的微波磁导率和较小的微波介电常数,以及相近的比饱和磁化强度.本文发展的方法对制备其他金属与无机氧化物的纳米复合材料也有重要指导作用.     

纳米Fe2O3-CuO复合氧化物的制备与电化学性能

采用水热法、沉淀法制备了纳米Fe2O3-CuO复合氧化物粉末作为锂离子电池负极材料,用XRD和TEM对其结构和形貌进行了分析和表征,并用充放电和循环性能等对其电化学性能进行了测试.结果表明,采用水热法可以制备出粒度分布较均匀、颗粒形状为块状、平均粒径约30 nm的纳米Fe2O3-CuO复合氧化物;采用沉淀法可以制备出粒...     

氢电弧等离子体法制备碳包铁纳米粒子

采用氢电弧等离子体法制备了碳包铁纳米粒子,通过X射线衍射仪(XRD)、透射电镜(TEM)、扫描电镜(SEM)、X射线能谱仪(EDS)、热重-差热分析仪(TG-DSC)等分析手段对粒子的成分、形貌,相结构,热性能等进行了表征.结果表明,制备的粒子中含有α-Fe、Fe3 C、无定形碳和石墨,没有铁的氧化物相出现.铁粒子外碳层的厚度为5～15nm,碳包铁纳米粒子的熔点为1360℃,碳层的存在增强了纳米粒子的抗酸蚀能力.     

氧化吸附法合成硝酸根型铜铁铝类水滑石

采用氧化吸附法制备了硝酸根型铜铁铝类水滑石,借助XRD、FTIR、SEM等分析手段研究了样品的结构、形貌及形成机理.结果表明:存在水蒸气的条件下,以碳酸根型铜铁铝类水滑石为前驱体经过500℃焙烧得到的铜铁铝复合氧化物可以氧化吸附NO2,生成Cu(NO3)2.上述样品在干燥器中放置9 d后转化成直径约为5μm的硝酸根型类水滑石.此外,铜铁铝复合氧化物吸附NO2、H2O和O2后也可直接转化成硝酸根型铜铁铝类水滑石,不存在中间相Cu(NO3)2.本文提出的氧化吸附法为制备类水滑石提供了一种新途径.     

P110钢CO2腐蚀产物膜的XPS分析

为了确定CO2腐蚀产物膜的组成及不同层次结构中成分和含量的差异,采用P110钢在高温高压腐蚀静态釜中制备CO2腐蚀产物膜,利用扫描电子显微镜(SEM)观察了腐蚀产物膜的表面和断面形貌,借助X射线衍射(XRD)的辅助,通过X射线光电子能谱(XPS)分析和研究了两层结构膜的化学组成差异.结果表明,腐蚀产物膜断面呈现双层结构;膜层的主要成分是FeCO3,还有少量的CaCO3和铁的氧化物,但内层CaCO3较多且夹杂着Fe3C和单质铁,外层氧化物稍多;通过内外层Ca2+含量差异推断内层腐蚀膜优先形成.     

铁氧化物薄膜气敏材料的制备及性能研究评述

本文综合介绍近年来在铁氧化物薄膜气敏材料制备方法、性能方面的研究新进展 ,探讨了各种方法的特点。提出了今后铁氧化物气敏传感器的研究及改进方向     

一种新型球状纳米氧化铁的制备

以Fe(NO₃)₃·9H₂O为原料、以尿素为沉淀剂,用热解前驱体法制备出直径为40~60 nm的球状纳米氧化铁。使用XRD、SEM和EDS等手段对其表征,研究了Fe³⁺浓度、反应温度等因素对纳米氧化铁的粒径和形貌的影响、确定了球状纳米氧化铁的制备条件并分析了球状纳米氧化铁的形成机理。结果表明：随着Fe(NO₃)₃·9H₂O溶液温度的提高纳米氧化铁的结晶度随之提高、粒径增大。Fe(NO₃)₃·9H₂O的浓度对纳米氧化铁样品的粒度和形貌的影响不大。球状氧化铁纳米的形成机理是：铁源在水热条件下水解和结晶生成棕黄色絮状沉淀FeOOH,FeOOH在高温高压条件下溶解和再结晶生成了球状纳米氧化铁。     

稀土氧化物纳米材料制备的研究进展

稀土氧化物纳米材料的合成与制备近年来已成为国内外学者研究的一个热点。本文介绍了国内外稀土氧化物纳米材料制备及合成方法的研究进展,并对稀土氧化物纳米材料的制备方法进行了分类。同时,综合比较了各自的优点和缺点,并对各种制备方法在各个领域的应用前景进行了一定的展望。     

Topotactic conversions of γ-FeOOH and comparative transformation methods of iron oxides in magnetic spinels

The DTA of a natural, well crystallized lepidocrocite sample containing small amounts of goethite, quartz and manganese shows that the conversion of γ-FeOOH to -Fe₂O₃ (through the γ-Fe₂O₃ metastable phase) occurs at 440°C, whereas in pure, synthetic γ-FeOOH the exothermic peak appears at ˜ 500°. Quartz (1.4% SiO₂) is not affected, nor does it hamper the transformation of FeOOH into magnetic spinels, when the sample is reacted with glycerol at reflux temperature followed by hydrolysis of the resulting solid (iron alkoxide) by boiling H₂O. Starting γ-FeOOH and final solid products are characterized by XRD and IR spectroscopy. This reaction is also discussed comparatively with the solid state transformations of iron oxides into magnetic materials by a combination of heating and grinding-pressing cycles of disks containing alkali halides as diluting agents.     

静电纺丝法制备纳米多孔氧化物的研究进展

简要阐述了静电纺丝法制备纳米多孔氧化物的基本原理,归纳分析了近年来已成功制备出的几种纳米多孔氧化物的材料特性和制备方法,总结了静电纺丝工艺参数对制备多孔氧化物的结构和形貌的影响规律,包括聚合物及其溶液性质,电压、电极间距、液体流速等纺丝条件,以及环境等因素。详细介绍了近几年国内外静电纺丝纤维在过滤及个体防护、传感器、自清洁和催化载体及其他一些特殊领域中的研究现状和静电纺丝的两种新方法、新技术,并对其技术发展方向及产业化前景进行了分析预测。     

Effect of functional groups on the crystallization of ferric oxides/oxyhydroxides in suspension environment

This paper investigated the effects of five kinds of Au surfaces terminated with and without functional groups on the crystallization of ferric oxides/oxyhydroxides in the suspension condition. Self-assembled monolayers (SAMs) were used to create hydroxyl (--OH), carboxyl (--COOH), amine (--NH₂) and methyl (--CH₃) functionalized surfaces, which proved to be of the same surface density. The immersion time of substrates in the Fe(OH)₃ suspension was divided into two time portions. During the first period of 2 h, few ferric oxide/oxyhydroxide was deposited except that ?-Fe₂O₃ was detected on--NH₂ surface. Crystallization for 10 h evidenced more kinds of iron compounds on the functional surfaces. Goethite and maghemite were noticed on four functional surfaces, and maghemite also grew on Au surface. Deposition of ?-Fe₂O₃ was found on--OH surface, while the growth of orthorhombic and hexagon FeOOH were indicated on--NH₂ surface. Considering the wide existence of iron compounds in nature, our investigation is a precedent work to the study of iron biomineralization in the suspension area.     

Novel Iron Oxyhydroxide Lepidocrocite Nanosheet as Ultrahigh Power Density Anode Material for Asymmetric Supercapacitors

A simple one‐step electroplating route is proposed for the synthesis of novel iron oxyhydroxide lepidocrocite (γ‐FeOOH) nanosheet anodes with distinct layered channels, and the microstructural influence on the pseudocapacitive performance of the obtained γ‐FeOOH nanosheets is investigated via in situ X‐ray absorption spectroscopy (XAS) and electrochemical measurement. The in situ XAS results regarding charge storage mechanisms of electrodeposited γ‐FeOOH nanosheets show that a Li⁺ can reversibly insert/desert into/from the 2D channels between the [FeO₆] octahedral subunits depending on the applied potential. This process charge compensates the Fe²⁺/Fe³⁺ redox transition upon charging–discharging and thus contributes to an ideal pseudocapacitive behavior of the γ‐FeOOH electrode. Electrochemical results indicate that the γ‐FeOOH nanosheet shows the outstanding pseudocapacitive performance, which achieves the extraordinary power density of 9000 W kg^?1 with good rate performance. Most importantly, the asymmetric supercapacitors with excellent electrochemical performance are further realized by using 2D MnO₂ and γ‐FeOOH nanosheets as cathode and anode materials, respectively. The obtained device can be cycled reversibly at a maximum cell voltage of 1.85 V in a mild aqueous electrolyte, further delivering a maximum power density of 16 000 W kg^?1 at an energy density of 37.4 Wh kg^?1.     

H2S‐Scavenged and Activated Iron Oxide‐Hydroxide Nanospindles for MRI‐Guided Photothermal Therapy and Ferroptosis in Colon Cancer

Overproduced hydrogen sulfide (H₂S) is of vital importance for the progress of colon cancer and promotes cancer cellular proliferation. Devising pharmacological nanomaterials for tumor‐specific H₂S activation will be significant for precise colon cancer treatment. Herein, a biocompatible fusiform iron oxide‐hydroxide nanospindles (FeOOH NSs) nanosystem for magnetic resonance imaging (MRI), ferroptosis, and H₂S based cascade reaction‐enhanced combinational colon cancer treatment is developed. The FeOOH NSs can effectively scavenge endogenous H₂S via the reduction reaction to prohibit the growth of CT26 colon cancer. The cascade produced FeS driven by overexpressed H₂S exhibits near‐infrared‐triggered photothermal therapy capability and Fe²⁺‐mediated ferroptosis functionality. Meanwhile, the as‐prepared FeOOH NSs can light up tumor tissues as a potent MRI contrast agent. Additionally, FeOOH NSs present desirable biosafety in a murine model for up to three months and avoid any long‐term toxicity. Furthermore, it is found that these H₂S‐responsible nanotheranostics do not cause any cure effects on other cancer types, such as 4T1 breast cancer. Overall, the findings illustrate that the biocompatible FeOOH NSs can be successfully employed as a theranostic for specifically treating colon cancer, which may promote the clinical translation and development of H₂S‐responsive nanoplatforms.     

非水介质中制备纳米氧化铁

在严格无水的条件下,制备了氧化铁纳米粒子,采用FTIR、XRD、TEM、TG-DTA、Mossbauer谱等方法对所得的纳米粒子进行了表征和分析.实验结果证明:室温晾干后,得到无定形的FeOOH超细粉体;通过控制热处理的温度;可以得到不同晶型的氧化铁纳米粒子.即:在300℃热处理1h,主要得到约30nm的Fe_3-xO₄,450℃处理1h,可得到粒径约为98nnm的α-Fe₂O₃粒子.     

2D sandwich-like sheets of iron oxide grown on graphene as high energy anode material for supercapacitors

2D sandwich-like sheets of iron oxide grown on graphene as high energy anode material for supercapacitors are prepared from the direct growth of FeOOH nanorods on the surface of graphene and the subsequent electrochemical transformation of FeOOH to Fe(3)O(4). The Fe(3)O(4) @RGO nanocomposites exhibit superior capacitance (326 F g(-1)), high energy density (85 Wh kg(-1)), large power, and good cycling performance in 1 mol L(-1) LiOH solution.