Fe^(3+)对细粒菱锌矿和方解石分散行为的影响

方解石矿泥的覆盖和高价金属阳离子的存在是影响粒径−20μm细粒菱锌矿浮选效果的关键因素,两者通过改变菱锌矿的表面性质而恶化其分散性和浮选环境。本文选择菱锌矿浮选中常见的Fe^(3+)为研究对象,通过吸附试验、Zeta电位、XPS分析,DLVO理论计算等考察Fe^(3+)对菱锌矿和方解石的分散行为规律和作用机理。结果表明:两种矿物对Fe^(3+)的吸附行为基本一致,但Fe^(3+)对菱锌矿分散行为的影响程度大于Fe^(3+)对方解石分散行为的影响。当Fe^(3+)浓度为5×10^(−4)mol/L时,菱锌矿分散行为被完全破坏。溶液化学及DLVO理论计算结果表明,Fe^(3+)吸附在矿物表面形成了羟基络合物或Fe(OH)3,导致菱锌矿颗粒间作用力小于方解石的,这是Fe^(3+)破坏菱锌矿分散行为、影响粒径−20μm细粒菱锌矿浮选的主要原因。

不同形态聚乙烯微塑料对Fe^(3+)的吸附性能

为探究聚乙烯(PE)微塑料的不同形态对Fe^(3+)吸附性能的影响,分析两者之间的相互作用。选用低密度聚乙烯(LDPE)和线型低密度聚乙烯(LLDPE)作为不同形态PE的代表,利用SEM、FTIR、吸附比表面测试法及Zeta电位表征其结构形貌,并通过静态吸附实验探讨不同形态PE对Fe^(3+)的吸附效果影响。结果表明LDPE相较于LLDPE具有更优的颗粒分散性、比表面积和表面负电性,其对Fe^(3+)的最大吸附量达到5.01 mg·L^(-1),PE对Fe^(3+)的吸附量随着微塑料投加量的增加先增大后减小,升温有利于吸附反应的进行。LDPE和LLDPE对Fe^(3+)的吸附均符合准一级动力学和朗缪尔模型,这表明吸附过程以单层物理吸附为主;颗粒内扩散模型表明吸附过程以表面吸附为主,且内扩散不是吸附速率控制的唯一步骤。此外,扩散力和静电力是LDPE和LLDPE吸附Fe^(3+)的主要作用机制,并且不受其线型结构的影响。

一例Eu-MOF材料的构筑及对Fe^(3+)与硝基芳香族爆炸物的荧光检测性能

金属阳离子和硝基芳香族爆炸物的大量排放对环境和人体健康造成了严重威胁,对它们的高效检测具有重要的研究意义和挑战性,金属-有机骨架(MOFs)是一类新型的荧光传感检测材料.本文采用溶剂热法合成了一例具有fcu拓扑结构的Eu-MOF材料,[(CH_(3))_(2)NH_(2)]_(2)[Eu_(6)(μ_(3)-OH)_(8)(EDDC)_(6)]·8DMA·3MeOH·6H_(2)O[JLUMOF128,H_(2)EDDC=(E)-4,4′-(乙烯-1,2-取代基)二苯甲酸],并通过单晶X射线衍射、粉末X射线衍射、X射线光电子能谱、红外光谱、元素分析和热重分析对其结构及组成进行了表征.结果表明,由于荧光配体H_(2)EDDC的引入,JLU-MOF128表现出显著的荧光性能,在DMF溶液中对Fe^(3+)、2,4,6-三硝基苯酚(TNP)和2,4-二硝基苯酚(2,4-DNP)具有较好的检测效果,Ksv值分别为2.09×10^(4),8.49×10^(4)和5.75×10^(4)L/mol,检测限分别为5.99,1.51和1.93μmol/L.在金属阳离子和硝基芳香族爆炸物的检测方面,JLU-MOF128是一种理想的多感应荧光传感材料.

含酚类煤化工废水自还原Fe^(3+)类芬顿体系研究

煤化工废水水质复杂,难降解有机物及氨氮含量高,给废水处理带来较大难度。现有的煤化工废水处理技术(混凝法、吸附法、膜生物反应法等)具有成本高、运行不稳定、预处理效果差等缺陷,难以满足煤化工行业发展的需要。为了高效处理煤化工废水,本文利用煤化工废水中酚类有机物的还原性促进Fe^(3+)/Fe^(2+)的循环,提出了一种利用Fe^(3+)/H_(2)O_(2)类芬顿体系处理煤化工废水的方法。实验结果表明:Fe^(3+)/H_(2)O_(2)体系中COD、TOC、TN、NH3-N的去除率可以达到74.63%、52.62%、10.46%、15.11%;相比于其他体系,Fe^(3+)/H_(2)O_(2)体系出水色度明显降低,UV-Vis光谱下降幅度最大,铁泥量也明显减少。Q-TOF分析结果表明:废水中主要的8种有机物为酚类或具有醛基、羰基、羧基、碳碳双键或者酯基等还原性的官能团。通过测定COD去除率和pH、Fe^(3+)/Fe^(2+)、H_(2)O_(2)等含量随时间的变化趋势,提出了Fe^(3+)/H_(2)O_(2)体系去除有机物的机理:废水中的还原性有机物将Fe^(3+)还原为Fe^(2+),促进Fe^(3+)/Fe^(2+)循环,生成的Fe^(2+)与H_(2)O_(2)发生芬顿反应,实现废水中有机污染物的去除。利用控制变量法,确定了最佳运行工况为:Fe_(2)(SO_(4))_(3)添加量为1.0 g/L、H_(2)O_(2)添加量为50 mmol/L、反应温度为30℃、初始pH为6.8。在此工况下,反应60 min后,煤化工废水的COD、TOC、TN、NH_(3)-N去除效果良好,色度明显降低,BOD_(5)和COD的比值(B/C)从0.17提升至0.47,可生化性大幅提高。本文证实了利用含酚类煤化工废水自还原Fe^(3+)/H_(2)O_(2)体系的可行性,降低了运行成本,可为后续研究及工程应用提供理论基础。

Fe^(3+)对浮钨尾矿中受抑萤石的活化作用及其与方解石浮选分离的影响

白钨矿、萤石和方解石的浮选中,抑制剂的加入往往会增加后续萤石、方解石浮选分离的难度。通过浮选实验、吸附量测试、Zeta电位测量及溶液化学计算,研究了Fe^(3+)对浮钨尾矿中受抑萤石的活化作用及其与方解石浮选分离的影响及机理。单矿物浮选实验结果表明,Fe^(3+)单独添加对方解石的抑制作用远大于萤石。水玻璃单独添加时,两种矿物同时被抑制。在pH为8.0、水玻璃用量为300 mg/L、油酸钠用量为1.5×10^(-4)mol/L的条件下,萤石、方解石浮选回收率分别为13.49%和16.83%。水玻璃体系中引入Fe^(3+),在pH为8.0、水玻璃用量为75 mg/L、Fe^(3+)用量为3×10^(-4)mol/L、油酸钠用量为1.5×10^(-4)mol/L的条件下,萤石、方解石浮选回收率分别为82.01%和15.64%,Fe^(3+)的加入提高了水玻璃体系中受抑萤石的可浮性,选择性活化了萤石,机理分析表明,Fe^(3+)更容易在方解石表面发生吸附,阻碍了油酸钠的吸附。水玻璃体系中加入Fe^(3+)后,溶液中Fe^(3+)的水解组分Fe(OH)^(2+)、Fe(OH)_(4)^(-)选择性地与萤石表面水玻璃的水解组分Si(OH)_(4)、SiO(OH)_(3)^(-)发生化学反应,生成Fe^(+)-水玻璃聚合物,使得萤石表面的水玻璃水解组分含量减少,恢复了萤石的可浮性,而Fe^(+)-水玻璃聚合物则较多地在方解石表面发生吸附,更加抑制了方解石的浮选。

养殖废水中Fe^(3+)累积对藻菌共生体EPS分泌及膜污染特征的影响

通过在养殖废水中分别投加不同浓度的Fe^(3+)进行藻菌共生体的培养,探究Fe^(3+)对藻菌共生体胞外聚合物(EPS)分泌的影响,并将提取的EPS各组分拆分,结合膜污染测试实验考察藻菌共生体混合液和其各组分导致的膜污染特征变化情况。实验结果表明,Fe^(3+)的加入通过影响EPS各组分的含量可有效减缓膜污染,在其投加质量浓度为150 mg/L时,膜污染最轻。采用Hermia经典模型对膜通量衰减过程进行拟合分析,结果发现,滤饼层的形成是膜污染形成的主要原因之一,此外Fe^(3+)增加会引起微生物絮体粒径变化,进而对膜污染产生显著影响。膜面污染物成分分析发现,其主要组成成分为色氨酸类蛋白质、酪氨酸类蛋白质和微生物代谢副产物。

绿萝制备蓝色荧光碳量子点及对Fe^(3+)的检测

以绿萝为原料,通过水热法合成了蓝色荧光碳量子点(CQDs),考察了原料质量浓度、水热温度、CQDs浓度对CQDs荧光强度的影响,确定了最佳工艺条件:原料质量浓度3.3g/L、反应温度260℃、反应时间4h,此条件下制备的CQDs荧光强度最高。同时研究了盐离子浓度、紫外灯光照射时间、溶液pH对CQDs荧光强度的影响,结果表明CQDs有较好的盐稳定性和光稳定性,对pH有一定的依赖性,酸性条件下CQDs荧光强度相对较高。傅里叶变换红外光谱、X射线光电子能谱分析表明CQDs表面含有羟基、羧基等官能团,在水中有良好的溶解性。Fe^(3+)对CQDs的荧光有明显的猝灭作用,其他金属离子对其干扰性小,基于荧光强度与Fe^(3+)浓度之间的线性关系,CQDs能快速地检测水溶液中Fe^(3+)浓度,最低检测限为0.77μmol/L。

基于Fe^(3+)-DA-APS自催化体系的Fe_(3)O_(4)/PAA水凝胶的制备及性能研究

以Fe_(3)O_(4)纳米粒子为磁性组分,基于AA(丙烯酸)与部分Fe3O4反应产生的Fe3+、多巴胺(DA)构建双重自催化过硫酸铵(APS)的自由基聚合体系,在低温下制备了Fe_(3)O_(4)/聚丙烯酸(PAA)水凝胶,并对其进行表征。研究结果表明:Fe_(3)O_(4)/PAA水凝胶具有良好的力学性能,断裂伸长率、拉伸强度分别为900%、251.1 kPa;同时,其可较好粘附不同基材,在钢材上粘附-剥离循环20次后粘附强度仍稳定在30.7 kPa左右;此外,其还可感应极小形变,并在166 ms内快速响应。该Fe_(3)O_(4)/PAA水凝胶综合性能良好,具备应用于柔性传感器等领域的潜力。

5,10,15,20-四(五氟苯基)卟啉聚集体荧光增强检测Fe^(3+)

以再沉淀法,使用四氢呋喃作为良溶剂溶解5,10,15,20-四(五氟苯基)卟啉(TPPP),水作为不良溶剂诱导组装,于常温下构筑了TPPP聚集体,对其形貌结构及发光性质进行了表征。研究发现该聚集体在Fe^(3+)存在的情况下,荧光会明显增强,因此该聚集体可作为荧光探针来检测Fe^(3+)离子。通过检测,确定了在5.0×10^(-8)~5.18×10^(-6)mol/L的Fe^(3+)浓度范围内,荧光探针荧光强度与Fe^(3+)浓度之间呈线性关系,R^(2)=0.99356,并计算得到了检出限为2.97×10^(-8)mol/L。此外,TPPP聚集体荧光探针在检测Fe^(3+)时具有较好的选择性和抗干扰性。最后通过纯净水、自来水、矿泉水的加标实验证明其具有良好的可行性,加标回收率在95.02%~104.73%之间。

Preparation and Characterization of Fe^(3+)-doped Nanometer TiO_2 Photocatalysts

Fe^3＋ -doped nanometer TiO2 photocatalysts were prepared by sol-gel technique. TiO2 powders with different Fe^3＋ / Ti^4 ＋ molar ratios ranging from 0. 05% to 25% were synthesized by calcinating the gels in the temperature range of 200-600 ℃ . The effects of the content of iron ions and calcination temperature on the physical properties of the powders and their photocatalytic activities were examined by the photodecorapositon of methyl orange in sunlight. The results show that Fe dopant can decrease the temperature of nanatase-ratile transformation. The ideal photocatalytic property was achieved when the sample with an Fe^3＋ / Ti^4＋ ratio of 20 at% was calcined at about 300 ℃ for an hour, which is superior to that of commercial Degussa P-25. The optimum microstructure of the Fe-doped TiO2 for a high photocatalytic activity in sunlight is consisted of nanatase and ratile.

B位Fe^(3+)掺杂Na_(0.5)Bi_(0.49)TiO_(3)陶瓷的电导性能

采用固相合成法制备了x=0,0.02,0.04和0.06的Na_(0.5)Bi_(0.49)Ti_(1-x)Fe_(x)O_(3-δ)(NBT)粉末材料,经压制成型并在1000~1150℃烧结制备了片状陶瓷样品。通过XRD,SEM和EIS测试研究了Fe^(3+)掺杂量x对NBT陶瓷性能的影响。结果表明,NBT材料在掺杂Fe^(3+)后出现了新相NaBiTi_(6)O_(14),且含量随x的增加而变多。材料在掺杂后的烧结温度降低了100~150℃,同时材料的晶粒变得细小。在300~700℃测试温度范围内,x=0.02,0.04和0.06的样品的电导率在相同温度下都处于同一数量级,相对于x=0的样品的电导率提升了约1000倍。x=0.04的样品具有最高的电导率,在600℃和700℃的测试温度下,电导率分别达到9.8 mS/cm和17.0 mS/cm。

LiLu(MoO_(4))_(2):Eu^(3+)的制备及其对Fe^(3+)离子的荧光检测研究

Fe^(3+)在生命过程中扮演着重要的角色,开发一种能够快速定量检测Fe^(3+)离子的荧光探针有着重要意义。采用溶胶-凝胶法成功制备了四方相白钨矿结构的LiLu(MoO_(4))_(2):Eu^(3+)荧光粉,粒径为1~2μm;通过荧光光谱研究了所得荧光粉的光学性质,确定了Eu^(3+)的最佳发光掺杂摩尔浓度为15%。所得LiLu(MoO_(4))_(2):15%Eu^(3+)对Fe^(3+)离子的检测下限为14.4μmol/L,并且具有高选择性和抗干扰性。

Defect engineering on BiFeO_(3) through Na and V codoping for aqueous Na-ion capacitors

Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Compared to Li^(+) storage,Na^(+) storage makes higher demands on the structural optimization of perovskite bismuth ferrite(BiFeO_(3)).We propose a novel strategy of defect engineering on BiFeO_(3) through Na and V codoping for high-efficiency Na^(+) storage,to reveal the roles of oxygen vacancies and V ions played in the enhanced electrochemical energy storage performances of Na-ion capacitors.The formation of the oxygen vacancies in the Na and V codoped BiFeO_(3)(denoted as NV-BFO),is promoted by Na doping and suppressed by V doping,which can be demonstrated by XPS and EPR spectra.By the first-principles calculations,the oxygen vacancies and V ions in NV-BFO are confirmed to substantially lower the Na^(+)migration energy barriers through the space and electric field effects,to effectively promote the Na^(+) transport in the crystals.Electrochemical kinetic analysis of the NV-BFO//NV-BFO capacitors indicates the dominant capacitive-controlled capacity,which depends on fast Na^(+) deintercalation-intercalation process in the NV-BFO electrode.The NV-BFO//NV-BFO capacitors open up a new avenue for developing highperformance Na-ion capacitors.

NPCl-CDs/Fe^(3+)荧光探针的制备及对L-Cys的传感检测

以葡萄糖、乙二胺、浓盐酸和浓磷酸作为反应前体,采用一步水热法合成了一种蓝绿色的荧光碳点NPCl-CDs,并以此构建了NPCl-CDs/Fe^(3+)荧光探针用于实际样品中L-半胱氨酸(L-Cys)的定量检测.实验结果表明,在NPCl-CDs中加入Fe^(3+)可使NPCl-CDs的荧光猝灭,当向NPCl-CDs/Fe^(3+)猝灭体系中引入L-Cys时,体系的荧光强度得以恢复.由此构建了一种用于L-Cys定量检测的新型“开-关-开”NPCl-CDs/Fe^(3+)-L-Cys荧光传感系统.该方法在5.8~60.0μmol/L浓度范围内呈现较宽的线性区域,检出限为0.052μmol/L.该荧光传感系统对L-Cys表现出良好的选择性,对实际样品中L-Cys的检测具有潜在的应用价值.

Preparation and Characterization of Nanotitanium Dioxide Coating Film Doped with Fe^(3+) Ions on Porous Ceramic

The nanotitanium dioxide （TiO2） photocatalytic and porous ceramic filtering technique is one of the advanced methods to effectively treat organic wastewater. The TiO2 sol doped with Fe^3＋ ions was prepared by sol-gel processing. The influences of the process conditions of coating nanophotocatalytic material- Fe^3＋-TiO2 film on the surface of porous ceramic filter by dipping-lift method on the performance of porous ceramic filter were studied. The porous ceramic filters have two functions at the same time, filtration and photocatalytic degradation. The results of this study showed that the pH and viscosity of the sol, amount of Fe^3＋ ions doped as well as the coating times greatly affect the quality of coating film, the performance parameters and the photocatalytic activity of the porous ceramic filter. When the pH of the sol is 3-4, the viscosity is about 6 mPa.S, the amount of doped Fe^3＋ ions is about 2.0 g/L, the porous ceramic filter has been shown to have the best filtering performance and photocatalytic activity. In this condition, the porosity of porous ceramic is about 42.5%, the pore diameter is 8-10μm. The degradation of methyl-orange is 74.76% under lighting for 120 rain.

不同因素对Fe^(3+)-TiO_(2)/ACF降解NH_(3)的影响

为了探究不同因素对Fe^(3+)-TiO_(2)/活性炭纤维(ACF)降解氨气(NH_(3))的影响规律,采用Fe^(3+)-TiO_(2)/ACF复合材料,以NH_(3)为目标降解物,研究初始浓度、流速、光催化剂负载量以及光照强度对Fe^(3+)-TiO_(2)/ACF降解NH_(3)的影响,并进行了相应的反应动力学分析。结果表明:随着初始浓度的增加,NH_(3)降解率呈现略微降低的趋势,光催化过程基本符合L-H一级反应动力学模型;随着流速的增加,NH_(3)降解率表现为先升高后降低,其光催化过程也基本符合L-H一级反应动力学模型;随着光催化剂负载量以及光照强度的增加,NH_(3)降解率表现为略微增加的趋势。

Researches on the Growth Habit and Optical Properties of Fe^(3+) Ion Doped KDP Crystal

During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different concentration of Fe^3＋ dopant by traditional temperaturereduction method and ＂point-seed＂ rapid growth method. Furthermore, we examined the light scatter and measured the transmission of these KDP crystals. It is found that the dopant of Fe^3＋ ion can improve the stability of the KDP growth solution when its concentration is less than 30 ppm. The effects of Fe^3＋ ion on the growth habit and optical properties of KDP crystal are also obvious.

O-doping strategy enabling enhanced chemical/electrochemical stability of Li_(3)InCl_(6) for superior solid-state battery performance

Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.

Enhancing potassium-ion storage of Bi_(2)S_(3) through external–internal dual synergism: Ti_(3)C_(2)T_(x) compositing and Cu^(2+) doping

Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode electrode materials.Here,we propose a dual synergic optimization strategy to enhance the K^(+)storage stability and reaction kinetics of Bi_(2)S_(3) through two-dimensional compositing and cation doping.Externally,Bi_(2)S_(3) nanoparticles are loaded onto the surface of three-dimensional interconnected Ti_(3)C_(2)T_(x) nanosheets to stabilize the electrode structure.Internally,Cu^(2+)doping acts as active sites to accelerate K^(+)storage kinetics.Various theoretical simulations and ex situ techniques are used to elucidate the external–internal dual synergism.During discharge,Ti_(3)C_(2)T_(x) and Cu^(2+)collaboratively facilitate K+intercalation.Subsequently,Cu^(2+)doping primarily promotes the fracture of Bi2S3 bonds,facilitating a conversion reaction.Throughout cycling,the Ti_(3)C_(2)T_(x) composite structure and Cu^(2+)doping sustain functionality.The resulting Cu^(2+)-doped Bi2S3 anchored on Ti_(3)C_(2)T_(x)(C-BT)shows excellent rate capability(600 mAh g^(-1) at 0.1 A g^(–1);105 mAh g^(-1) at 5.0 A g^(-1))and cycling performance(91 mAh g^(-1) at 5.0 A g^(-1) after 1000 cycles)in half cells and a high energy density(179 Wh kg–1)in full cells.

锌金属有机骨架材料在食品Fe^(3+)检测中的应用

以2,2',5,5'-偶氮苯四羧酸(ABTC)、1,2,4-三氮唑(Tz)和硝酸锌为原料合成的一种锌金属有机骨架材料([(CH_(3))_(2)NH_(2)][Zn_(2)(ABTC)(Tz)]·3DMF)作为研究对象,用荧光光谱法对该材料的荧光特性进行探究。测试结果显示,相较于其他离子而言,Fe^(3+)离子的样品溶液发光强度猝灭效果最为明显,并且Zn-MOF材料对Fe^(3+)离子有良好的猝灭效果和选择性。利用Zn-MOF材料的这一特性,在实验中以Zn-MOF材料作为荧光探针来测定食品(紫菜、猪肝粉、奶粉、核桃和牛肉)中Fe^(3+)的含量。