均匀纺锤形α—FeOOH粒子的合成

本文以ＦｅＳＯ４、７Ｈ２Ｏ和Ｎａ２ＣＯ３为原料，制备晶形、粒度、轴比等满足高性能磁粉要求的均匀纺锤形α－ＦｅＯＯＨ粒子，研究考察了碱比、〔Ｆｅ＾２＋〕起始浓度、温度、搅拌转速、气量等工艺参数对合成均匀纺锤形α－ＦｅＯＨ粒子的影响规律，并制备出长轴为０．２￣０．３μｍ、轴比为４：１的、大小均匀、分散性好、无枝叉的纺锤形α－ＦｅＯＯＨ粒子。     

α－FeOOH制备新工艺──Ⅰ原料净化

利用氧化－絮凝工艺除去炼钢厂副产的工业级硫酸亚铁晶体杂质，作为酸法合成α－ＦｅＯＯＨ粒子的原料，合成出晶体粒径为０．２μｍ，分布均匀，无枝叉，分散性好的α－ＦｅＯＯＨ。     

超微细密度铁磁记录材料的合成研究：（Ⅱ）—γ—Fe2O3的合成

采用有机还原剂还原α－ＦｅＯＯＨ（α－Ｆｅ２Ｏ３）制备Ｆｅ３Ｏ４,用空气氧化法氧化Ｆｅ３Ｏ４制成γ－Ｆｅ２Ｏ３,并对γ－Ｆｅ２Ｏ３进行改性处理。通过对合成γ－Ｆｅ２Ｏ３的性能测定,其饱和磁化强度４πＭ′ｓ为４７５,矫顽力Ｈｃ１．２为５００,轻敲密度Ｄ为１．２,具有良好的耐磨性,在树脂胶合剂中具有比普通γ－Ｆｅ２Ｏ３更好的分散性。对方法的可靠性论证中。磁性体的比饮和磁化强度平均值为４７１,标准偏差为     

α—FeOOH制备新工艺——I原料净化

利用氧化－絮凝工艺除去炼钢厂副产的工业级硫酸亚铁晶体杂质，作为酸法合成α－ＦｅＯＯＨ粒子的原料，合成了晶体粒径为０．２μｍ，分布均匀，无枝叉，分散性好的αＦｅＯＯＨ。     

超微细高密度铁磁记录材料的合成研究——(Ⅱ)γ-Fe_2O_3的合成

采用有机还原剂还原α－ ＦｅＯＯＨ（含α－ Ｆｅ２ Ｏ３ ）制备Ｆｅ３Ｏ４ ,用空气氧化法氧化Ｆｅ３Ｏ４ 制成γ－ Ｆｅ２Ｏ３ ,并对γ－ Ｆｅ２Ｏ３ 进行改性处理。通过对合成γ－ Ｆｅ２Ｏ３ 的性能测定,其饱和磁化强度４πＭ′ｓ为４７５,矫顽力Ｈｃ１．２ 为５００,轻敲密度Ｄ为１２,具有良好的耐磨性,在树脂胶合剂中具有比普通γ－ Ｆｅ２Ｏ３ 更好的分散性。对方法的可靠性论证中,磁性体的比饱和磁化强度的平均值为４７１,标准偏差为±１０２％ ,矫顽力的平均值为３８９,标准偏差为±２０％ ,方法的再现性好。     

纺锤形α—FeOOH粒子制备

本文通过液相法利用ＦｅＳＯ４和Ｎａ２ＣＯ３为原料制备纺锤形α－ＦｅＯＯＨ超细粒子，考查反应温度、浓度和碱比等工艺配方以及加料方式、通气量及搅拌转速等宏观工程因素对最终α－ＦｅＯＯＨ粒子形貌的影响，成功地制备出大小为０．２μｍ左右，轴比３－４，均匀，无枝杈的纺锤形α－ＦｅＯＯＨ粒子。     

用掺杂方法提高α—FeOOH表观密度

在用碱法制备α－ＦｅＯＯＨ，进而合成γ－Ｆｅ２Ｏ３磁粉的过程中，经常加入Ｚｎ＾２＋离子以改善磁粉粒的针形，但因Ｚｎ＾２＋离子的电荷少于Ｆｅ＾３＋离子，因而能使α－ＦｅＯＯＨ晶体产生缺陷，最终影响磁粉的性能，本文通过在制备α－ＦｅＯＯＨ过程中掺入杂质Ｍｎ＾２＋的方法，探讨消除α－ＦｅＯＯＨ晶体缺陷，提高其表观密度，改善磁粉性能。     

铁酸盐纳米材料的制备

以硫酸盐为原料,按ｎ（Ｆｅ２ ＋ ）∶ｎ（ＮａＯＨ）∶ｎ（ＮａＨＣＯ３） ＝１∶１ ．８∶２．０ 添加ＮａＯＨ 和ＮａＨＣＯ３ ,制备出晶粒细小的碱式碳酸盐前驱体,干燥后在５００℃通气焙烧１ｈ,分别制备出ＺｎＦｅ２ Ｏ４ 、ＮｉＦｅ２ Ｏ４和ＣｏＦｅ２ Ｏ４ 纳米材料,经ＸＲＤ和ＴＥＭ检测,粒径为４０～５０ｎｍ ,粒度均匀     

酸化破乳—Fenton试剂氧化—混凝沉淀处理电子感光废水的研究

用酸化破乳－Ｈ２Ｏ２／ Ｆｅ２＋氧化－混凝沉淀处理印刷线路板感光乳化废水。讨论了 ｐＨ值、Ｈ２Ｏ２的浓度、Ｆｅ２浓度对ＣＯＤ去除的影响。结果表明,酸化破乳、Ｆｅｎｔｏｎ试剂氧化的ｐＨ值控制在３～４,混凝沉淀ｐＨ值控制在９～１０,Ｈ２Ｏ２浓度为０．０６ｍｇ·Ｌ－１,Ｆｅ２＋浓度为０．８ｍｇ·Ｌ－１,反应温度为１４０℃左右时,ＣＯＤ总去除率达９３．６％,具有良好的应用前景。     

针状α－FeOOH制备新工艺──Ⅱ γ－Fe_2O_3的制备

本文利用炼钢厂副产工业级的ＦｅＳＯ_４·７Ｈ_２Ｏ，为原料，经净化后合成超微α－ＦｅＯＯＨ粒子。考查了铁黄表面包硅与铁黄的热处理工艺，得到粒径为０．２５μｍ，粒度分布均匀，无枝叉，无碎晶，磁性能好的γ－Ｆｅ_２Ｏ_３磁粉。研究结果对现有磁粉生产厂的改进与完善有现实指导意义。     

Hydrothermal growth mechanism of α-Fe₂O₃ nanorods derived by near in situ analysis

The hydrothermal growth mechanism of α-Fe?O? nanorods has been investigated using a novel valve assisted pressure autoclave. This approach has facilitated the rapid quenching of hydrothermal suspensions into liquid nitrogen, providing 'snapshots' representative of the near in situ physical state of the synthesis reaction products as a function of known temperature. Examination of the acquired samples using complementary characterisation techniques of transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy (FT-IR) has provided fundamental insight into the anisotropic crystal growth mechanism of the lenticular α-Fe?O? nanorods.An intermediate ?-FeOOH phase was observed to precipitate alongside small primary α-Fe?O? nanoparticles. Dissolution of the ?-FeOOH phase with increasing temperature, in accordance with Ostwald's rule of stages, led to the release of Fe3+ anions back into solution to supply the growth of α-Fe?O? nanoparticles, which in turn coalesced to form lenticular α-Fe?O? nanorods. The critical role of the PO?3? surfactant on mediating the lenticular shape of the α-Fe?O? nanorods is emphasised. Strong phosphate anion absorption on α-Fe?O? crystal surfaces stabilised the primary α-Fe?O? nanoparticle size to < 10 nm. FT-IR investigation of the quenched reaction products provided evidence for PO?3? absorption on the α-Fe?O? nanoparticles in the form of mono or bi-dentate (bridging) surface complexes on surfaces normal and parallel to the crystallographic α-Fe?O? c-axis, respectively. Monodentate PO?3? absorption is considered weaker and hence easily displaced during growth, as compared to absorbed PO?3? bi-dentate species, which implies the α-Fe?O? c-planes are favoured for the oriented attachment of primary α-Fe?O? nanoparticles, resulting in the development of filamentary features which act as the basis of growth, defining the shape of the lenticular α-Fe?O? nanorods.     

α-Fe_2O_3纳米颗粒的可控制备及其性能研究

以DBS(十二烷基磺酸钠)为形态控制试剂,在水-丁醇体系中成功合成了准立方体形貌的α-Fe2O3纳米颗粒。通过扫描电子电镜(SEM)、X-射线衍射仪(XRD)、透射电子电镜(TEM)、紫外分析光谱(UV-vis)以及振动样品磁强计(VSM)等手段等对产物进行了表征。研究表明,体系中DBS含量对α-Fe2O3的生成和形貌有着重要的影响,在DBS含量较少时主要得到α-FeOOH纳米棒,而随着DBS含量增大得到α-Fe2O3纳米准立方体,获得的准立方α-Fe2O3纳米颗粒有着优异的室温磁性能。     

Ionothermal synthesis of aggregated α-Fe₂O₃ nanoplates and their magnetic properties

Aggregated α-Fe(2)O(3) nanoplates have been successfully synthesized under ionothermal conditions through the self-assembly of nanoplatelets in a side-to-side manner. During the formation process of aggregated α-Fe(2)O(3) nanoplates, pure ionic liquid media is essential for the assembly and coalescence of small nanoplatelets into final nanoplates. Moreover, the magnetic properties of the aggregated α-Fe(2)O(3) nanoplates are strongly correlated to their unique structural characteristics.     

氧化铁纳米材料的制备、表征及磁性研究

采用水热法,以三氯化铁为铁源,以聚乙烯吡咯酮（ PVP）和十六烷基三甲基溴化铵（ CTAB）为表面活性剂,合成了α-Fe2 O3纳米棒和纳米立方体,并用X-射线衍射仪（ XRD）、扫描电子显微镜（ SEM）和磁学测量系统（ SQUID-VSM）对其进行了表征。结果：以PVP为表面活性剂所制备的α-Fe2 O3纳米材料为平均直径约为70 nm,长度约300 nm纳米棒,以CTAB为表面活性剂所制备的α-Fe2 O3纳米材料为边长700 nm的准立方体,而不加表面活性剂所制备的样品的为无形貌的氧化铁纳米材料;其室温磁化强度和矫顽力分别为Mr 0．07 emu／g, Hc 2300 Oe;Mr 0．2 emu／g, Hc 3600 Oe;Mr 0．15 emu／g, Hc 3100 Oe。结论：表面活性剂对样品的形貌和磁性具有重要影响。     

固相反应合成铋酸钇

以Y2O3、Y(C2H3O2)3和Bi2O3为原料,采用高温固相反应合成铋酸钇(YBiO3)。借助热重-差热、X射线衍射、SEM等分析手段,探讨了不同原料、煅烧温度、保温时间、预烧等因素对铋酸钇合成的影响。结果表明:高温固相反应能够合成高纯度的铋酸钇;与Y(C2H3O2)3相比,Y2O3是合成YBiO3的较佳原料,其合成YBiO3的最低温度是766℃左右,YBiO3的开始分解温度是917℃左右;合成YBiO3的较佳工艺为两磨两烧,在800℃预烧90min,其较佳工艺参数为煅烧温度为900℃,保温时间120min。     

Monodisperse α-Fe2O3 Mesoporous Microspheres: One-Step NaCl-Assisted Microwave-Solvothermal Preparation, Size Control and Photocatalytic Property

A simple one-step NaCl-assisted microwave-solvothermal method has been developed for the preparation of monodisperse α-Fe2O3 mesoporous microspheres. In this approach, Fe(NO3)3 · 9H2O is used as the iron source, and polyvinylpyrrolidone (PVP) acts as a surfactant in the presence of NaCl in mixed solvents of H2O and ethanol. Under the present experimental conditions, monodisperse α-Fe2O3 mesoporous microspheres can form via oriented attachment of α-Fe2O3 nanocrystals. One of the advantages of this method is that the size of α-Fe2O3 mesoporous microspheres can be adjusted in the range from ca. 170 to ca. 260 nm by changing the experimental parameters. High photocatalytic activities in the degradation of salicylic acid are observed for α-Fe2O3 mesoporous microspheres with different specific surface areas.     

A magnetically separable photocatalyst based on nest-like γ-Fe₂O₃/ZnO double-shelled hollow structures with enhanced photocatalytic activity

Magnetic nest-like γ-Fe(2)O(3)/ZnO double-shelled hollow nanostructures have been successfully synthesized via a multi-step process. The materials have been thoroughly characterized by different techniques. These interesting nest-like hollow nanostructures are composed of ZnO nanoflakes grown on the surface of γ-Fe(2)O(3) hollow spheres. Importantly, these magnetic hollow nanostructures show very high visible-light photocatalytic activity for the degradation of different organic dyes including methylene blue (MB), Rhodamine-B (RhB), and methyl orange (MO). It is further demonstrated that these γ-Fe(2)O(3)/ZnO hybrid photocatalysts are highly stable and can be used repeatedly.     

Ni2+/surfactant-assisted route to porous α-Fe2O3 nanoarchitectures

Uniform porous three-dimensional nanoarchitectures of α-Fe(2)O(3) with high yield have been synthesized by a route based on a Ni(2+)/surfactant system. The obtained α-Fe(2)O(3) has a flue-like porous morphology with a rough surface. What is more, spatially ordered nodes and meshes are presented in these networks. By adjusting the experimental parameters such as temperature, reaction time, proportion of Ni(2+)/PVP and types of cation, we can control the morphology of the samples well. A possible formation mechanism is proposed to explain the growth of the flue-like nanostructures. The obtained flue-like porous α-Fe(2)O(3) has a large specific surface area of 88.82 m(2) g(-1). It exhibits significantly enhanced visible-light-driven photocatalytic performance in the degradation of methylene blue, compared with α-Fe(2)O(3) nanoparticles. This work not only enriches the synthesis methods of porous architectures, but also facilitates the applications of α-Fe(2)O(3) in the fields of water treatment, sunlight utilization and so forth.     

高热稳定性α-氧化铁的宏量制备及其电化学性能研究

氧化铁(Fe2O3)是一种重要的n型半导体材料,被广泛应用于染料、废水处理、光催化和锂离子电池等领域。采用水热法合成了不同直径大小的片状结构的α-氧化铁,其中大尺寸的片状α-氧化铁在1000℃仍能保持原有的表观颜色和形态,证明了其具有高热稳定性,在油漆、染料等领域具有较大的应用潜力。研究了氢氧化钠与三氯化铁溶液浓度及其混合顺序对α-氧化铁材料性能的影响,并且分析了片状α-氧化铁的带隙、锂离子电池性能及粉体表观颜色与颗粒尺寸的依赖关系。结果表明,通过调整氢氧化钠溶液的浓度和氢氧化钠与三氯化铁的滴加顺序可以得到不同尺寸的片状α-氧化铁,α-氧化铁的颜色随着其颗粒尺寸的增大而加深,带隙随着颗粒尺寸的减小呈现上升趋势,并且纳米级颗粒相对于微米级颗粒会提高锂离子电池的实际容量。该研究有助于研发α-氧化铁的宏量制备工艺及发掘其在电化学、陶瓷釉料、颜料等方面的应用,对降低传统能源活动的碳排放、推动中国早日实现“双碳”的国家目标具有重要的意义。     

固体超强酸La3+-SO42-/TiO2-Fe2O3催化合成对羟基苯甲酸丁酯

以固体超强酸La3+-SO42-/TiO2-Fe2O3为催化剂合成了对羟基苯甲酸丁酯,考察了原料配比、催化剂用量、反应温度和反应时间等因素对产品收率的影响。试验结果表明:La3+-SO42-/TiO2-Fe2O3是合成对羟基苯甲酸丁酯的良好催化剂,当n(丁醇)/n(对羟基苯甲酸)=4.0,催化剂用量为对羟基苯甲酸质量的6%,反应温度120℃,反应时间4.0 h,对羟基苯甲酸丁酯的收率达到89.27%。