L-半胱氨酸改性Fe3O4纳米粒子的水热合成及其应用

以L-半胱氨酸为表面改性剂与粒径调节剂,采用水热法制备具有良好分散稳定性的磁性Fe₃O₄纳米粒子。通过透射电镜（TEM）、扫描电镜（SEM）、X射线衍射仪（XRD）、比磁饱和强度测定仪（VSM）等对产物进行表征,研究L-半胱氨酸对磁性Fe₃O₄纳米粒子的形貌、粒径分布、晶型结构、分散稳定性等的影响,理论推导了L-半胱氨酸改性后的Fe₃O₄纳米粒子（L-Fe₃O₄纳米粒子）的生成机制,将该材料作为载体吸附金种后探讨其在催化对硝基苯酚方面的应用。结果表明：沉降22 h时,调节pH值为7.0制备的Fe₃O₄纳米粒子的沉降高度大约是L-Fe₃O₄纳米粒子的6.5倍;吸附金种后的L-Fe₃O₄纳米粒子催化效率大约是未改性Fe₃O₄纳米粒子的5倍。L-半胱氨酸有效的改善了Fe₃O₄纳米粒子与分散介质之间的相容性,保护并改善了纳米粒子的分散稳定性,在污水处理等方面有潜在的应用。     

A highly selective magnetic sensor with functionalized Fe/Fe3O4 nanoparticles for detection of Pb2+

A magnetic sensor for detection of Pb~(2+) has been developed based on Fe/Fe_3O_4 nanoparticles modified by3-(3,4-dihydroxyphenyl)propionic acid(DHCA). The carboxyl groups of DHCA have a strong affinity to coordination behavior of Pb~(2+) thus inducing the transformation of Fe/Fe_3O_4 nanoparticles from a dispersed to an aggregated state with a corresponding decrease, then increase in transverse relaxation time(T_2) of the surrounding water protons. Upon addition of the different concentrations of Pb~(2+) to an aq. solution of DHCA functionalized Fe/Fe_3O_4 nanoparticles(DHCA-Fe/Fe_3O_4 NPs)([Fe] = 90 mmol/L), the change of T_2 values display a good linear relationship with the concentration of Pb~(2+) from 40 μmol/L to 100 μmol/L and from 130 μmol/L to 200 μmol/L, respectively. Owing to the especially strong interaction between DHCA and Pb~(2+), DHCA-Fe/Fe_3O_4 NPs exhibited a high selectivity over other metal ions.     

A facile and green synthetic approach toward fabrication of starch-stabilized magnetite nanoparticles

A facile and green synthetic approach for fabrication of starch-stabilized magnetite nanoparticles was implemented at moderate temperature. This synthesis involved the use of iron salts, potato starch,sodium hydroxide and deionized water as iron precursors, stabilizer, reducing agent and solvent respectively. The nanoparticles(NPs) were characterized by UV-vis, PXRD, HR-TEM, FESEM, EDX, VSM and FT-IR spectroscopy. The ultrasonic assisted co-precipitation technique provides well formation of highly distributed starch/Fe_3O_4-NPs. Based on UV–vis analysis, the sample showed the characteristic of surface plasmon resonance in the presence of Fe_3O_4-NPs. The PXRD pattern depicted the characteristic of the cubic lattice structure of Fe_3O_4-NPs. HR-TEM analysis showed the good dispersion of NPs with a mean diameter and standard deviation of 10.68 4.207 nm. The d spacing measured from the lattice images were found to be around 0.30 nm and 0.52 nm attributed to the Fe3O4 and starch, respectively. FESEM analysis confirmed the formation of spherical starch/Fe_3O_4-NPs with the emission of elements of C, O and Fe by EDX analysis. The magnetic properties illustrated by VSM analysis indicated that the as synthesized sample has a saturation magnetization and coercivity of 5.30 emu/g and 22.898 G respectively.Additionally, the FTIR analysis confirmed the binding of starch with Fe_3O_4-NPs. This method was cost effective, facile and eco-friendly alternative for preparation of NPs.     

Magnetic responsive polymer nanofiber composites for easy collecting chemical spills

We describe a simple method to prepare magnetic responsive polydivinylbenzene(PDVB)nanofiber composites by precipitated cationic living polymerization in the present of oleic acid capped Fe3O4 nanoparticles(NPs).The Fe3O4 NPs are encapsulated with the PDVB forming dendrites,from which thin nanofibers are grown in the tip-growth mode.The thin nanofibers are interwoven with the thick nanofibers forming robust composite network.The composites are magnetic responsive and highly efficient to gel almost all chemicals.Separation of the gelled chemicals from water becomes easier with a magnet.The performance is promising for magnetic collection of chemical spills.     

纳米Fe2O3和Fe3O4的制备及其催化高氯酸铵热分解性能的研究——一个仪器分析综合实验

介绍一个仪器分析综合实验——纳米Fe_2O_3和Fe_3O_4的制备及其催化高氯酸铵热分解性能的研究。采用水热法合成纳米Fe_3O_4,进而煅烧得到纳米Fe_2O_3。使用X射线粉末衍射(XRD)对制得的样品结构进行表征,通过透射电镜(TEM)可以发现其为球形颗粒,粒径在10–20 nm范围内。将制得的纳米Fe_2O_3和纳米Fe_3O_4按不同比例加入高氯酸铵(AP)中,通过对混合物进行热分析(TG-DSC),发现纳米Fe_2O_3和纳米Fe_3O_4可以明显促进AP的分解,且Fe_2O_3的催化效果优于Fe_3O_4的催化效果,并对催化机理进行了简单讨论。通过该实验,可以让学生学习水热反应的方法,掌握利用XRD、热分析等多种手段对化合物结构及性能进行表征的技能。     

表面分子印迹磁性纳米粒子的制备及其血红蛋白传感应用

以Fe₃O₄磁性纳米粒子为载体、多巴胺（DA）为功能单体、血红蛋白（Hb）为模板分子,用氯铂酸氧化DA生成聚多巴胺（PDA）,同时氯铂酸还原为铂纳米粒子（PtNPs）,与Hb一起负载于Fe₃O₄纳米粒子表面,洗脱Hb后合成了表面分子印迹磁性纳米粒子（印迹Fe₃O₄/PDA-PtNPs）. 将印迹Fe₃O₄/PDA-PtNPs修饰于磁性玻碳基底表面,制得印迹Fe₃O₄/PDA-PtNPs修饰电极. 实验结果表明,印迹Fe₃O₄/PDA-PtNPs具有良好的水溶性,粒径分布均匀,生成的PtNPs具有良好的导电性和刚性. 用印迹Fe₃O₄/PDA-PtNPs构建的传感器对Hb具有良好的识别性,在0.14 ~ 2.7 μg·mL^-1 Hb浓度范围与交流阻抗变化值呈良好的线性关系,检出限（S/N=3）为0.05 μg·mL^-1.     

Fe3O4@PI催化剂的制备及其费托合成性能

分别采用水热、水热-包覆、球磨法制备了Fe_3O_4、聚酰亚胺(PI)改性的Fe_3O_4@PI和Fe_3O_4-PI催化剂用于费托合成反应,对比研究了PI改性及其含量变化对Fe基催化剂催化CO加氢产物分布的影响规律。结合XRD、SEM、TEM、H_2-TPR、COTPD、FT-IR、XPS、TG和接触角实验等手段对催化剂样品进行了表征。结果表明,Fe_3O_4、Fe_3O_4@PI和Fe_3O_4-PI样品均为球形颗粒; PI改性促进了Fe_3O_4的还原,亲水性增强。Fe_3O_4@PI样品中,PI均匀包覆于Fe_3O_4表面,具有较好的热稳定性;与Fe_3O_4、Fe_3O_4-PI相比,Fe_3O_4@PI样品CO吸附增强。在CO加氢反应中,与Fe_3O_4相比,PI改性的Fe_3O_4@PI和Fe_3O_4-PI样品催化活性下降,二次加氢能力受到抑制,烯烃选择性提高; Fe_3O_4@PI样品烯烃选择性增加明显,烯烷比(O/P)由改性前的0.50提高至2.15;适宜含量的PI改性促进C5+烃生成。     

磁性纳米复合物的制备及对铜离子(Ⅱ)的传感检测

采用化学共沉淀法合成硅包覆的磁性纳米粒子Fe_3O_4@SiO_2,进一步通过六亚甲基二异氰酸酯将吡哆酰肼分子(Pyh)接枝到Fe_3O_4@SiO_2表面,制得功能化的磁性纳米复合物(Fe_3O_4@SiO_2-Pyh)。通过傅里叶变换红外光谱、透射电子显微镜、X射线衍射等技术手段对其结构、形貌和磁性能进行了表征。Fe_3O_4@SiO_2-Pyh粒子具有规则的核壳结构,粒径分布在50~55 nm,壳层厚度约为15 nm。Fe_3O_4@SiO_2-Pyh结构中含有酰腙类活性基团—CO—NH—N=CH—,能与Cu~(2+)形成稳定的配合物,在此基础上采用紫外可见吸收光谱特性建立了测定Cu~(2+)的分析方法,线性范围为3.4×10~(-7)~4.5×10~(-6)mol/L,检出限为1.03×10~(-7)mol/L。此外,利用Fe_3O_4@SiO_2-Pyh良好的磁响应,通过外部磁场能够有效地除去水中过量的铜离子,在环境领域具有潜在的应用价值。     

Fe2O3/Al2O3氧载体用于甲烷化学链燃烧：负载量与制备方法的影响

以不同方法制备了系列Fe₂O₃/Al₂O₃氧载体,采用XRD、H₂-TPR、CH₄-TPR、O₂-TPD和BET等分析技术对氧载体进行了表征。研究了不同Fe₂O₃负载量氧载体的甲烷化学链燃烧性能,考察了不同制备方法对Fe₂O₃/Al₂O₃氧载体结构、反应性和产物选择性的影响。结果表明,Fe₂O₃负载量对氧载体活性及产物中CO₂选择性的影响较大,负载量较低时氧载体活性较低且引起甲烷部分氧化产物CO含量增加。制备方法亦对氧载体与甲烷的反应活性有所影响,整体上共沉淀法制备的质量分数60％Fe₂O₃/Al₂O₃氧载体具有较高的氧化活性和化学链循环稳定性。其在反应温度850℃、反应时间15 min、30次循环后甲烷转化率及产物中CO₂选择性均未见明显降低。     

磁性印迹纳米粒子固定血红蛋白修饰磁性电极构建过氧化氢传感器

采用表面印迹技术,以磁性二氧化硅纳米粒子（Fe₃O₄@SiO₂ NPs）作为载体、血红蛋白（Hb）为模板分子、正硅酸乙酯（TEOS）为印迹聚合物单体,制备了Hb印迹Fe₃O₄@SiO₂的磁性印迹纳米粒子（MMIPs NPs）. MMIPs NPs具有磁性内核和血红蛋白印迹壳层的核壳结构,可以富集并固定Hb. 使用壳聚糖将MMIPs NPs固定于磁性电极表面,构建血红蛋白类酶生物传感器,研究了Hb对过氧化氢（H₂O₂）的催化活性. MMIPS NPS相比于磁性非印迹纳米粒子（MNIPS NPS）,催化电流增加了14.3%. 采用磁性电极,MMIPS NPS、Hb和O₂的顺磁性使得该类酶生物传感器对H₂O₂的催化电流增加了60.0%. 血红蛋白类酶生物传感器电流响应与H₂O₂浓度在25 ~ 200 μmol·L^-1间呈线性关系,检出限为3 μmol·L^-1（S/N=3）,表明该类酶传感器对H₂O₂具有良好的催化性能.     

SO_4~(2-)功能化处理对Fe_2O_3催化剂上氨选择性催化还原NO_x性能的促进机理研究

采用沉淀法制备了Fe(OH)_3和Fe_2O_3。通过硫酸化处理得到SO_4~(2-)/Fe(OH)_3和SO_4~(2-)/Fe_2O_3两种催化剂,并将其应用于氨选择性催化还原NO_x(NH_3-SCR)反应,研究了SO_4~(2-)功能化处理对Fe_2O_3催化剂上NH_3-SCR脱硝性能的促进机理。结果表明,与纯的Fe_2O_3相比,硫酸化处理得到的催化剂上SCR活性得到显著提升;其中,SO_4~(2-)/Fe(OH)_3表现出更加优异的催化性能,在250-450℃时NO_x转化率高于80%,且具有优异的稳定性和抗H_2O+SO_2性能。XRD、Raman、TG、FT-IR、H_2-TPR、NH_3-TPD和in situ DRIFTS等表征结果显示,硫酸功能化处理能抑制Fe_2O_3的晶粒生长,同时SO_4~(2-)与Fe~(3+)结合形成硫酸盐复合物,提高了催化剂表面酸性位点的数量和酸强度,抑制了Fe_2O_3上的氨氧化反应,从而提高了其脱硝催化性能。     

Pt/Au/Fe3O4的制备及其电化学性能

以制得的纳米Fe₃O₄颗粒作为载体,用还原法将还原出的Au与Pt分别负载到Fe₃O₄颗粒表面,制得纳米Pt/Au/Fe₃O₄复合材料。对Pt/Au/Fe₃O₄进行紫外可见光吸收光谱、透射电子显微镜、X射线衍射及光电子能谱等物理表征,结果表明,Au与Pt均匀地沉积到了Fe₃O₄纳米颗粒表面。对纳米Pt/Au/Fe₃O₄复合材料进行循环伏安扫描,当H₂PtCl₆的加入量达到8 mL时,Pt/Au/Fe₃O₄催化性能最佳;正扫电流峰i_p与扫描速率的平方根v^1/2线性相关,Pt/Au/Fe₃O₄催化氧化甲醇的过程受扩散控制;对催化剂进行201次循环伏安扫描,催化剂仍然能保持较好的催化性能且稳定性良好。因此,所合成催化剂Pt/Au/Fe₃O₄是一种具有良好化学稳定性的阳极催化剂材料。     

Vc-Functionalized Fe3O4 Nanocomposites as Peroxidase-like Mimetics for H2O2 and Glucose Sensing

A simple and efficient colorimetric biosensing for hydrogen peroxide and glucose with peroxidase-like vitamin C(V_c) functionalized Fe₃O₄ magnetic nanoparticles(V_c/Fe₃O₄MNPs) as a catalyst is reported. Compared with Fe₃O₄ MNPs and other catalysts, V_c/Fe₃O₄ MNPs exhibited superior catalytic properties. Kinetic studies indicated that vitamin C incorporated on Fe₃O₄ MNPs improved the affinity toward H₂O₂. As low as 0.29 μmol/L H₂O₂ can be detected with a wide linear range of 0.5—100 μmol/L H₂O₂; moreover, as low as 0.288 μmol/L glucose can be detected with a linear range of 0.5—25 μmol/L glucose. The detection method was highly sensitive in sensing H₂O₂ and glucose. The robustness of V_c/Fe₃O₄ MNPs rendered them suitable for wide ranging applications.     

Application of response surface methodology for optimization of Orange Ⅱ removal by heterogeneous Fenton-like process using Fe_3O_4nanoparticles

In this study, Fe3O4nanoparticles（Fe3O4NPs） were successfully prepared via oxidation–precipitation method and characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and Fourier transform infrared spectroscopy（FT-IR）. The characterization results indicated that Fe3O4 NPs with regular crystal structure and a narrow of diameters had been synthesized successfully and had high purity. A series of experiments were carried out to investigate the degradation of Orange II by the obtained heterogeneous Fe3O4 catalysts in the presence of H2O2. The response surface methodology（RSM） based on Box–Behnken design（BBD） was employed to design and optimize individual and interactive effects of the four main independent parameters（catalyst loading, initial p H, reaction temperature and H2O2concentration） on decolorization efficiency of Orange II. A significant quadratic model（p-value 〈0.0001, R2= 0.9369） was derived using analysis of variance（ANOVA）. Optimum conditions were catalyst loading of 1.5 g/L, initial p H of 2.7, reaction temperature of 42 8C and H2O2 concentration of 22 mmol/L, respectively. The predicted decolorization rate under the optimum conditions as determined by the proposed model was 99.55%. Confirmatory tests were carried out and the decolorization rate of 99.49% was observed under the optimum conditions, which agreed well with the model prediction.     

Mo/Fe3O4(111)表面对燃煤烟气汞吸附的密度泛函研究

利用CASTEP软件包采用密度泛函理论计算研究了过渡金属Mo掺杂Fe_3O_4(111)Fe_(tet)表面对Hg~0、HgCl和HgCl_2的吸附特征,分析了Mo掺杂前后Fe_3O_4(111)Fe_(tet)表面上不同汞物种的吸附形态。结果表明,Mo掺杂Fe_3O_4(111)Fe_(tet)表面对HgCl和HgCl_2为化学吸附,而对Hg~0的吸附为物理吸附;与纯净表面相比,HgCl在Mo原子掺杂表面上的吸附能提高了40%-66%。HgCl_2在纯净Fe_3O_4(111)Fe_(tet)表面形成"M"形结构;而掺杂Mo原子后,由于Cl原子与Mo原子之间更强的相互作用,使得HgCl_2发生了完全解离,两个Cl原子分别与Mo原子和Fe原子成键吸附在表面,Hg脱附。相关研究结果可为脱除燃煤烟气中的汞提供一定的理论指导。     

Pd/Fe3O4-C催化剂对甲醇、乙醇和丙醇氧化的电催化活性

制备对醇氧化反应具有优异电活性的钯催化剂是醇燃料电池研究的重要内容。本文用硼氢化钠还原法制备了钯纳米颗粒, 然后沉积在Fe3O4/C复合物表面, 得到了不同Fe₃O₄负载量的Pd/Fe₃O₄-C催化剂. 透射电镜（TEM）图显示钯纳米颗粒均匀地分散在Fe₃O₄/C表面. 对制备好的Pd/Fe₃O₄-C催化剂进行了循环伏安法（CV）、计时电流（CA）和电化学阻抗谱（EIS）的测试, 研究了其在碱性介质中对C1-C3醇类（甲醇、乙醇和丙醇）氧化的电催化活性. 结果表明, 所制备的不同Fe₃O₄负载量的Pd/Fe₃O₄(2%)-C,Pd/Fe₃O₄(5%)-C, Pd/Fe₃O₄(10%)-C和Pd/C催化剂中, Pd/Fe₃O₄(5%)-C催化剂表现出最高的醇氧化电流密度. 依据循环伏安（CV）数据,Pd/Fe₃O₄(5%)-C催化剂对甲醇、乙醇、正丙醇和异丙醇氧化的阳极峰电流密度分别是Pd/C催化剂的1.7、1.4、1.7和1.3倍. Pd/Fe₃O₄(5%)-C催化剂对乙醇氧化的电荷传递电阻也远低于Pd/C催化剂. 制备的所有催化剂对C1-C3醇类电氧化的电流密度大小排序如下: 正丙醇﹥乙醇﹥甲醇﹥异丙醇. 此外, 碳粉中Fe₃O₄纳米颗粒的存在提高了钯纳米颗粒的电化学稳定性.     

用于磁性靶向治疗肺纤维化的聚多巴胺包覆的Fe3O4/甲强龙/环磷酰胺复合超粒子

肺纤维化是一种致命性肺部疾病, 目前临床常规的甲强龙(MPS)联合环磷酰胺(CTX)治疗方法存在明显的不良反应. 基于降低药物毒副作用的目的, 本文设计了一种聚多巴胺(PDA)包覆的Fe₃O₄纳米粒子/甲强龙/环磷酰胺复合超粒子(Fe₃O₄/MPS/CTX@PDA SPs), 提出磁性靶向治疗肺纤维化的思路. 从预制的油溶性Fe₃O₄纳米粒子出发, 通过水包油微乳液模板法制备了Fe₃O₄ 超粒子(SPs), 并在进一步包覆PDA壳层的过程中引入MPS和CTX, 制备了Fe₃O₄/MPS/CTX@PDA SPs, 考察了Fe₃O₄/MPS/CTX@PDA SPs的稳定性、 磁性、 对MPS和CTX的负载及释放, 分析了其生物毒性, 并建立动物模型验证了其磁性靶向功能.     

静电自组装方法合成的具有多孔三维网络结构的Fe_3O_4/石墨烯复合材料作为高性能锂离子电池负极材料(英文)

采用静电自组装方法,分两步合成Fe(OH)3/GO前驱体(GO:氧化石墨烯),再通过水热反应和600°C高纯氮气气氛下煅烧,获得了Fe3O4/石墨烯复合材料.通过X射线衍射(XRD)、扫描电镜(SEM)、高分辨透射电镜(HRTEM)、拉曼(Raman)光谱等多种分析,发现该复合材料具有三维多孔石墨烯网络结构.把合成的这种Fe3O4/石墨烯复合材料作为锂离子电池负极材料,电化学测试结果表明其具有优良的电化学性能:首次放电容量为1390 mAh·g-1,50次循环后容量为819 mAh·g-1.通过对比实验表明,三维石墨烯网络结构的形成对复合材料的电化学循环稳定性起着关键作用.     

An efficient and facile one-pot synthesis of propargylamines by three-component coupling of aldehydes, amines, and alkynes via C-H activation catalyzed by NiCl2

NiCl₂ was found to be a highly efficient and effective catalyst for the one-pot three-component (A³) coupling of aldehydes, amines, and alkynes to produce propargylamines in nearly quantitative yields. Structurally divergent aldehydes, amines, and alkynes were converted into the corresponding propargylamines. No co-catalyst or activator is needed and water is the only byproduct of this novel protocol.     

磁性纳米颗粒Fe3O4的醇改性制备机理及应用

利用化学沉淀法, 以乙二醇(EG)、 聚乙二醇(PEG)和甘露醇(D-M)分别为表面改性剂制备了改性的Fe₃O₄颗粒(分别命名为E-Fe₃O₄, P-Fe₃O₄和D-Fe₃O₄). 实验结果显示, 醇类分子能成功地修饰在Fe₃O₄颗粒表面, 但 未改变其形貌、 大小、 晶相和磁性．采用傅里叶变换红外光谱、 离子选择性电极法、 Zeta电位和接触角等 手段研究其改性机理, 发现P-Fe₃O₄和D-Fe₃O₄样品表面醇修饰与水分子介导的氢键有关, E-Fe₃O₄则通过表面羟基直接与乙二醇形成了更稳定的氢键, 即使经热处理(120 ℃)乙二醇分子仍被固定在Fe₃O₄表面. 表面带有疏水基团的E-Fe₃O₄具有适中的亲水性(接触角32.92°)和水中分散性(粒径200~300 nm). 带负电荷的E-Fe₃O₄被应用于水中阳离子染料结晶紫(CV)的吸附和磁性分离, 对CV吸附量为19.33 mg/g, 是未改性前(8.41 mg/g)的2.3倍, 通过外加异丙醇可以促进CV脱附．