Adsorption of Fe^(3+) Ions from Aqueous Solution by Natural and Synthetic Apatites: Kinetic, Equilibrium and Thermodynamic Study

In this study, the adsorption kinetics, equilibrium and thermodynamics of Fe3+ ions on natural (NAP) and synthetic (HAP) apaties were examined. The adsorption efficiency of Fe3+ onto the NAP and HAP was increased with increasing temperature. The kinetics of adsorption of Fe3+ ions was discussed using three kinetic models, the pseudo-first-order, the pseudo-second-order and the intra-particle diffusion model. The experimental data fitted very well the pseudo-second-order kinetic model. The initial sorption rate and the activation energy were also calculated. The activation energy of the sorption was calculated as 37.15 and 49.84 kJ·mol 1 for NAP and HAP, respectively. Experimental results were also analysed by the Langmuir, Freundlich and Dubinin–Redushkevich (D–R) isotherm equations at different temperatures. RL separation factor for Langmuir and the n value for Freundlich isotherm show that Fe3+ ions are favorably adsorbed by NAP and HAP. Various thermodynamic parameters such as enthalpy (ΔH), Gibbs free energy (ΔG) and entropy (ΔS) changes were computed and the results showed that the adsorption of Fe3+ ions onto NAP and HAP were spontaneous and endothermic in nature.

Photocatalytic Activity of Nanosized TiO_2 Enhanced by co-doping with Fe^(3+) and Nd^(3+) Ions

In this study, nanosized TiO2 co-doped with Fe3+ and Nd3+ ions was synthesized via a sol-gel method. The metallic ion doped TiO2 was thoroughly characterized with XRD and UV-vis, and the photocatalytic activity was evaluated by degrading methylene blue (MB) solution. The results indicated that TiO2 crystalline size was reduced and phase transformation of anatase to rutile was suppressed as the content of doped Nd3+ ion increased in the co-doped TiO2. The UV-vis spectra of co-doped TiO2 seemed to simply overlay two spectra of single metal doped TiO2, and had significantly increased absorbance in the ranges of 400～500 nm, 565～600 nm and 730～765 nm as compared to pure TiO2. The photocatalytic activity of co-doped TiO2 was obviously enhanced, and raised about 30% compared to that of pure TiO2 as doped Nd3+ content was 0.15% and Fe3+ content was 0.05%, respectively. The enhanced catalytic activity was attributed to a synergistic effect of two doped ions, where doped Fe3+ ion inhibited the recombination of photogenerated electron and hole, and Nd3+ ion brought more surface carboxyl to promote the degradation reaction.

Design of Fe(3–x)O4 raspberry decorated graphene nanocomposites with high performances in lithium-ion battery

Fe（3–x）O4 raspberry shaped nanostructures/graphene nanocomposites were synthesized by a one-step polyol-solvothermal method to be tested as electrode materials for Li-ion battery（LIB）. Indeed, Fe（3–x）O4 raspberry shaped nanostructures consist of original oriented aggregates of Fe（3–x）O4 magnetite nanocrystals, ensuring a low oxidation state of magnetite and a hollow and porous structure, which has been easily combined with graphene sheets. The resulting nanocomposite powder displays a very homogeneous spatial distribution of Fe（3–x）O4 nanostructures at the surface of the graphene sheets. These original nanostructures and their strong interaction with the graphene sheets resulted in very small capacity fading upon Li＋ion intercalation. Reversible capacity, as high as 660 m Ah/g, makes this material promising for anode in Li-ion batteries application.

二甲基姜黄素对Fe^(3+)的选择性识别研究

以姜黄素和碘甲烷为原料,一步合成了二甲基姜黄素分子探针L,其结构经X-射线单晶衍射、~1H NMR,^(13)C NMR和ESI-MS等分析手段确证。该化合物晶体属单斜晶系,空间群C2/c,晶胞参数:a=22.317(6)nm,b=8.703 8(19)nm,c=23.039(5)nm,β=93.378(10)°,V=4 467.4(18)nm3,Z=4,Dc=1.206 g·cm-3,F(000)=1 720,μ(MoKα)=0.088 mm-1,R=0.080 9,ωR=0.216 3。探针L在甲醇-水溶液(体积比9∶1,Tris-HCl缓冲溶液,p H 7.2)中对Fe^(3+)具有选择性识别和较强的抗干扰能力。通过紫外滴定以及质谱确证探针L与Fe^(3+)形成1∶1配合物,结合常数(K)为1.089×106L/mol。该识别体系在Fe^(3+)浓度为5.5×10-6~3×10^(-5)mol/L范围内具有较好的线性关系(r2=0.997 8),检出限为2.2×10^(-6)mol/L。

柠檬酸三钠对Co^(2+)-Ni^(2+)-Fe^(3+)-CO_3^(2-) LDHs形貌及其离子交换性能的影响

Co2+/Ni2+/Fe3+摩尔比为0.5/3/1,采用络合剂柠檬酸三钠协助均相沉淀技术,制备了Co2+-Ni2+-Fe3+-LDHs层状材料,研究了柠檬酸三钠用量对Co2+-Ni2+-Fe3+LDHs层间距及形貌的影响。在此基础上,研究了不同层间距和不同形貌Co2+-Ni2+-Fe3+-23CO--LDHs层状材料的离子交换性能,即Co2+-Ni2+-Fe3+-23CO-LDHs层状材料在Na Cl-HCl的离子交换体系中进行阴离子交换反应,生成Co2+-Ni2+-Fe3+-Cl–-LDHs层状材料。研究结果表明:当柠檬酸三钠用量为0.6~1.0 mmol/L时,所制备的LDHs层间距为0.776 nm,片层结构分散性较好,产物的较大层间距和较好形貌使其仍保持良好的离子交换性能,并通过离子交换反应可分别得到4Cl O-、24SO-、3NO-、4Mn O-及CH3(CH2)113SO-插层Co2+-Ni2+-Fe3+-LDHs层状衍生材料;当柠檬酸三钠用量在1.5 mmol/L时,所制备的LDHs层间距为0.770 nm和0.691 nm,片层结构团聚并成玫瑰花形貌,使得客体离子较难插入到层间,产物的离子交换性能降低;当柠檬酸三钠的量增加到3.0 mmol/L时,得到的LDHs层间距为0.681 nm,片层结构变小,团聚现象加剧,LDHs片完全交错生长成球状形貌,产物完全失去了离子交换性能。

噻唑并[3,2-a]嘧啶-5-酮衍生物的合成及其对Fe^(3+)的识别

以丁二酸酐、三乙二醇单甲醚为原料,经酯化、酰化后与7-(3-氨基噻吩并[2,3-b]吡啶-2-基)-噻唑并[3,2-a]嘧啶-5-酮反应,制备荧光探针L,利用核磁和质谱对其结构进行了表征。该探针L可在HEPES溶液中荧光"开-关"识别Fe^(3+),pH在3.4~6.4范围内识别效果较好,其他金属离子没有干扰,检测限可达2.534×10^(-4)M。

十二烷基磺酸根插层Ni^(2+)-Fe^(3+)/Co^(2+)-Ni^(2+)-Fe^(3+) LDHs及其结构研究

应用水热技术制备了二元Ni2+-Fe3+-CO23- LDHs和三元Co2+-Ni2+-Fe3+-CO32- LDHs,以十二烷基磺酸根离子作为插层客体,通过离子交换反应在酸性溶液中实现了十二烷基磺酸根插层Ni2+-Fe3+ LDHs和Co2+-Ni2+-Fe3+-LDHs。十二烷基磺酸根在Ni2+-Fe3+LDHs层间出现了2种空间导向和排列:即十二烷基磺酸根以单层垂直方向排布和以双层垂直方向排布在层间;十二烷基磺酸根在三元组分Co2+-Ni2+-Fe3+-LDHs层间只有一种空间排列方式,即十二烷基磺酸根以单层垂直方向排布于Co2+-Ni2+-Fe3+-LDHs层间。

负载Fe^(3+)强酸性离子交换树脂催化合成乙酸苄酯

用D072型强酸性阳离子交换树脂负载Fe3+,制备用于合成乙酸苄酯的催化剂。结果表明,树脂负载Fe3+的条件为:Fe3+起始浓度为32.55 mmol/L,负载时间为3.0 min,负载温度为35.0℃,烘干温度为50.0℃。树脂催化合成乙酸苄酯的反应条件为:乙酸与苯甲醇的摩尔比为1∶1,催化剂用量为乙酸质量的15.0%,反应温度100℃,反应时间200 min,乙酸的转化率为67.10%,其催化活性比原树脂的催化活性提高了14.66%。

Co^(2+)-Ni^(2+)-Fe^(3+)-CO_3^(2-)LDHs的水热合成及表征

以尿素作为沉淀剂,酒石酸钠作为络合剂,氮气作为保护气,借助于水热合成技术成功合成了高结晶性规则形貌三元组分Co2+-Ni2+-Fe3+-CO23-LDHs,通过XRD、SEM、FTIR、EDS、原子吸收等分析手段对合成产物进行了表征。

氮、硫掺杂石墨烯量子点的调控制备与Fe^(3+)传感分析

采用一步固相合成方法制备了荧光量子产率高达82%的N,S-GQDs。并通过对制备时间的调控,得到尺寸更大的氧化石墨烯纳米片。与未掺杂GQDs相比,N,S-GQDs表面电子特性及表面化学活性明显改变。所得到的N,S-GQDs可与Fe3+的特异性结合引起电子转移,导致N,S-GQDs的荧光猝灭。据此建立了高灵敏、高选择性传感Fe3+的定量分析方法,检出限为3.3nmol·L-1,线性范围0.01~3μmol·L-1。

Cu^(2+)和 Fe^(3+)与明胶的相互作用

利用荧光猝灭法，研究了不同温度、酸度下，Ｃｕ２＋和 Ｆｅ３＋与明胶的相互作用．计算了猝灭常数和结合常数．紫外光谱和显微红外光谱的测定结果表明，Ｃｕ２＋、Ｆｅ３＋与明胶分子中的酰胺键发生了作用．探讨了猝灭机理．计算出的热力学函数表明，在Ｃｕ２＋、Ｆｅ３＋与明胶的相互作用过程中熵变起主要的作用．

Fe_3(PO_4)_2固相法合成及其影响因素的研究

锂离子电池正极材料LiFePO4具有良好的发展前景。介绍了采用固相法合成Fe3P(O4)2的方法,并对实验现象进行了理论分析,用扫描电镜表征了实验产物的形貌。结果表明:Fe3P(O4)2的生成温度为200℃,但如果使反应进行完全,则需300℃以上;Fe3(PO4)2共有三种反应机理;温度和原始反应物的晶粒尺寸都会影响生成Fe3P(O42)晶粒的尺寸,温度越高,生成的Fe3P(O42)晶粒就越大,原始反应物的晶粒尺寸越小,生成的Fe3P(O4)2晶粒就越小。

R6G@γ-CD-MOFs复合物的制备及其在Fe^(3+)离子传感中的应用

利用γ‑环糊精(γ‑CD)、氢氧化钾、甲醇和水,制备了γ‑CD‑MOFs,并使用X射线粉末衍射、热重分析和扫描电镜对其结构、稳定性和形貌进行表征。由于γ‑CD‑MOFs的结构中含有一维孔道,在其孔道中引入黄光发射的罗丹明6G(R6G)染料,获得了荧光复合材料R6G@γ‑CD‑MOFs,并探索了其对不同金属离子的荧光响应情况。实验结果表明,R6G@γ‑CD‑MOFs能够从12种金属离子中选择性传感Fe^(3+)离子,在2×10^(-4)~2.0×10^(-2)mol·L^(-1)范围内其荧光猝灭常数(K_(sv))为1.03×10^(4)L·mol^(-1)。

Two alkynyl functionalized Co（Ⅱ）-MOFs as fluorescent sensors exhibiting selectivity and sensitivity for Fe3+ and nitroaromatic compounds

Two Co(II)-MOFs with different structures were successfully synthesized under the premise of designing two ligands containing alkynyl functional groups. Complexes 1 ([Co(TEPA)(TPT)2/3]·2DMF·H2O) and 2 ([Co(EPA)(TPT)]·1.5DMF·1.5H2O) show excellent luminescence properties. Meanwhile, as fluorescent sensors, complexes 1 and 2 exhibit selectivity and sensitivity for Fe3+ with the Ksv of 1.520 ×104 L/mol and 3.543 ×104 L/mol, which can rapidly detect nitroaromatic compounds in methanol and ethanol, especially for 2,4-NPH through fluorescence quenching with high quenching efficiency. In particular, the Ksv value of complexes 1 and 2 towards 2,4-NPH can reach up to 1.627 ×105 L/mol and 9.600 ×104 L/mol, demonstrating that complexes 1 and 2 are good candidates for the identification and detection of Fe3+and nitroaromatic compounds.

Fe^(3+)与PrP106-126共同诱导下N2a细胞的氧化应激状态

利用PrP106-126多肽的神经毒性,结合Fe3+对细胞氧化应激可能的诱导作用,建立N2a细胞的氧化应激模型,以研究氧化应激在Prion疾病过程中的作用,及其诱导神经细胞退行性损伤的机制。试验表明,通过毒性多肽PrP106-126与Fe3+共同作用,模拟神经细胞的氧化应激状态是可行的。效果较佳的攻毒浓度和攻毒时间分别是不高于50μmol/L的毒性PrP106-126多肽,不高于500μmol/L的Fe3+,最佳攻毒时间为12h。

用离子交换树脂从粉煤灰盐酸浸出液中除铁试验研究

研究了从粉煤灰盐酸浸出液中除Fe3+,考察了3种离子交换树脂在不同条件下吸附Fe3+的能力。试验结果表明,用D201型强碱性阴离子交换树脂(Cl型),以硫代硫酸钠作还原剂,EDTA作络合剂,结合还原络合法吸附除Fe3+,浸出液中Fe3+质量浓度可降至0.5g/L以下。

PrP106-126作用下N2a细胞线粒体的损伤机制

为探讨Prion相关疾病中神经细胞的损伤机制,应用毒性神经多肽PrP106-126与一定浓度的Fe3+离子共同作用,并通过测定细胞NADH活性评估细胞呼吸链功能状态,检测细胞线粒体膜电位的动态变化,及线粒体内细胞色素C的分布,探讨细胞在PrP106-126与Fe3+共同诱导的氧化应激条件下,N2a细胞线粒体可能的损伤及对整个细胞的影响。试验结果显示,毒性多肽与Fe3+作用下,N2a细胞的NADH酶活性显著下降(P<0.01),降低至正常活性的65%,细胞线粒体膜电位出现明显的去极化(P<0.01),细胞色素C自线粒体释放至细胞质中,并引起pro-caspase-9活化。

碳纳米管修饰的碳糊铁离子选择性电极的研究

以新型碳纳米管复合物修饰的碳糊铁离子选择性电极被研制出来。电极对Fe3+呈现近Nernst电位响应性能,电极响应的线性范围为1.8×10-8～1.0×10-1mol/L,斜率为26.3 mV/decade,检测下限为0.9×10-9mol/L。电极Fe3+具有良好的选择性,其响应时间为25 s。将此离子选择性电极应用于Fe3+的回收率实验,结果令人满意。

酸化返排液中无机离子对电导率的影响

酸化是油田增产增注的重要措施之一,但酸化返排液的电导率过高会引起流程中电脱水装置跳闸。本文研究渤海油田4口油井酸化后返排液中离子种类、含量及高价金属离子对返排液电导率的影响,结果表明:返排液中所含无机离子的种类基本一致;返排液中的离子总含量越高,其相应电导率越大;随着Ca^(2+)、Mg^(2+)和Fe^(3+)这3种特征离子浓度的增加,返排液的电导率逐渐增加,当离子质量浓度为1 000 mg/L时,3种返排液的电导率分别为57.8、59.7和55.4 mS/cm;特别地,Fe^(3+)对前期返排液电导率的提升能力约为同浓度下Ca^(2+)、Mg^(2+)的2~3倍。

高磁性微球的制备及在冶金废水处理中的应用

制备了一种高磁性氧化钛,氧化硅包覆四氧化三铁微球材料(Fe3O4@SiO2@TiO2),并通过透射电子显微镜和扫描电子显微镜对制备的材料进行表征。制备材料具有很好的分散性,可以很好地分散在水溶液中,通过外加磁场,分散的磁性材料可以很快和水体分离。氧化硅和氧化钛两层外壳很好地保护了铁核,因此制备的材料在酸性溶液中有很好的稳定性,可以用来固相萃取冶金废水中的金属离子。