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.

STUDY OF SURFACE RESISTIVITY MODIFICATION IN Al_2O_3 CERAMIC IMPLANTED BY Fe^(2+)

The implanted ion range, the depth profile and the film sttucture of the implanted layer were studied; the carrier concentration and the mobility were measured; the conductivity mechanism of the film implanted Fe into Al_2O_3 ceramic was discussed. The conclusion is that the implanted Fe^(2+) ions move into Al_2O_3 lattice and replace Al^(3+) to form subs- titution impurities so that the ion implanted lat- tice, as compared with the original one, presents an effective negative charge which forms a negative charge center. A vacancy is bound arround it, and an acceptor is introduced in the forbidden band.

基于罗丹明b类的Fe^(3+)荧光探针的合成及其性能研究

以2,6-吡啶二羰酰氯与罗丹明酰胺缩合反应的产物(BR)为荧光"关—开"型探针,研究了探针BR选择性识别Fe^(3+)的各种影响因素,建立了BR荧光检测分析痕量Fe^(3+)的方法.Job's Plot实验证明BR与Fe^(3+)的络合比为1∶2.且Fe^(3+)浓度在0~20μmol/L范围内与BR呈良好的线性关系(R^2=0.998),检出限为1.8×10^(-8)mol/L.

离子色谱法测定聚合铝铁中的Fe^(3+)、Fe^(2+)

采用酸溶解—离子色谱法分析聚合铝铁 (PAFC)中的Fe3+ 和Fe2 + ,具有快速、简便、准确的特点 ,两种价态的离子标准曲线线性关系良好 ,最低检测浓度 :Fe3+ 为 0 .0 18mg/L ,Fe2 + 为 0 .0 2 2mg/L 。

Highly sensitive Fe^(3+)luminescence detection via single-ion adsorption

To achieve a lower detection limit has always been a goal of analytical chemists.Herein,we demonstrate the first picomolar level detection capability for Fe3+ion via luminescence detection technology.The results of structural analysis and theoretical calculation show that Fe3+ions are adsorbed on the central node of Eu-DBM(DBM=dibenzoylmethane)sensor in the form of single ion at ultralow concentration.Subsequently,the pathways of photo-induced charge and energy transfer of the obtained Eu-DBM@Fe^(3+)material have been changed,from the initial DBM-to-Eu^(3+)before Fe^(3+)adsorption to the ultimate DBM-to-Fe^(3+)after adsorption process,which quenches the luminescence of Eu3+ion.This work not only obtains the highly sensitive luminescence detection ability,but also innovatively proposes the single-ion adsorption mechanism,both of which have important scientific and application values for the development of more efficient detection agents in the future.

FeCl3催化硫醇与亚胺离子的亲核反应

以γ-羟基内酰胺和硫醇为原料,1,2-二氯乙烷为溶剂,在三氯化铁促催化下生成亚胺离子,而后硫醇发生亲核反应构建3-硫醚基异吲哚啉酮类化合物。该反应70℃条件下搅拌6 h即可完成,产率87~94%,该反应底物适用范围广,对于不同的γ-羟基内酰胺类化合物以及不同的伯硫醇和仲硫醇,反应均可以顺利得到相应的产物。

N-doped carbon quantum dots as fluorescent probes for highly selective and sensitive detection of Fe^3+ ions

To investigate the effect of nitrogen on the photoluminescence properties of carbon quantum dots (CO Ds), N-doped carbon quantum dots (N-CQDs)were synthesized by one-step hydrothermal treatment using biomass tar as the carbon precursor.As an inevitable organic pollutant,the unsaturated bonds in biomass tar,such as carboxylic acids,aldehydes,and aromatics,are favorable for formation of the graphitic carbon lattice.The obtained N-CQDs are spherical with an average particle size of 2.64nm and the crystal lattice spacing is 0.25nm,corresponding to the (100)facet of graphitic carbon.The N-CQDs emit bright blue photoluminescence under 365nm ultraviolet light,and they have excellent water solubility and stability with a high quantum yield of 26.1%.Coordination between the functional groups on the N-CQD surface and Fe^3+ ions is promoted because of the improved electronic properties and surface chemical reactivity caused by N atoms,leading to a significant fluorescence quenching effect of the N-CQDs in the presence of Fe^3+ions with high selectivity and sensitivity.There is a linear relationship between In (Fo/F)and the Fe^3+ concentration in the N-CQD concentration range 0.06-1400μmol/L with a detection limit of 60nmol/L, showing that the N-CQ.Ds have great potential as a fluorescent probe for Fe^3+detection.

Ligand controlled structure of cadmium(Ⅱ) metal-organic frameworks for fluorescence sensing of Fe^(3+) ion and nitroaromatic compounds

Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.

Microwave-assisted synthesis of colorimetric and fluorometric dual-functional hybrid carbon nanodots for Fe^(3+) detection and bioimaging

Carbon nanodots(CDs) based fluorescent nanoprobes have recently drawn much attention in chemo-/bio-sensing and bioimaging.However,it is still challenging to integrate the colorimetric and fluorometric dual readouts into a single CD.Herein,novel hybrid CDs(HCDs) are prepared by a simple microwave-assisted reaction of citric acid(CA),branched polyethyleneimine(BPEI) and potassium thiocyanate(KSCN).As-prepared HCDs show extraordinary properties,including excitation-dependent emission,satisfactory fluorescence quantum yield(46.8%),excellent biocompatibility and optical stability.Significantly,the fluorescence intensity at 450 nm exhibits linear correlation over the Fe^(3+)concentration from 1 mmol/L to 150 mmol/L with a detection limit(LOD) of 52 nmol/L.Meanwhile,the solution color changes from colorless to orange,and the absorbance at 460 nm increased linearly with Fe^(3+)concentration ranging from 0.02 mmol/L to 5 mmol/L(LOD:3.4 mmol/L).All the evidence illustrates that the HCDs can be conditioned for specific Fe^(3+)sensing with colorimetric and fluorometric dual readouts,which has also been verified with paper-based microchips.The possible mechanism is attributed to the specific interactions between surface functional groups on the HCDs and Fe^(3+).Additionally,the HCDs are successfully applied in sensing Fe^(3+)in wastewater and living cells,demonstrating its potential applications in future environment monitoring and disease diagnosis.

A New Tetrasubstituted Imidazole Based Difunctional Probe for UV-spectrophotometric and Fluorometric Detecting of Fe^3+Ion in Aqueous Solution

Two new compounds,4-(2-bromophenxl-4,5-diphenyl-imidazol-1-yl)ani 1 ine(probe 1)and 4-[2,4,5-tris(4-bromopheny1)-1H-imidazol-1-y1]aniline(probe 2),were synthesized via a soft and high-efficiency one-pot microwave-assisted method under solvent-free conditions.Their sensing to different metal ions was detected by UV spectrophotometry and fluorescence spectrometry.Probe 2 revealed highly selective and sensitive UV and fluorescence response to Fe^3+ion.Upon the addition of Fe^3+ion,probe 2 showed obvious color change of the solution,conspicuous absorbance enhancement and relatively quick fluorescence quenching.The detection limit for Fe^3+ion was respectively calculated to be 0.72μmol/L(fluorescent detection)and 0.48μmol/L(UV-spectnim detection).Also,probe 2 was bound by Fe^3+ion to tonn a 1:1 complex.Moreover,preliminary application of probe 2 tor detecting Fe^3+ion in aqueous solution was attempted,and satisfying results were obtained.

Electrochemical synthesis of Ni doped carbon quantum dots for simultaneous fluorometric determination of Fe^(3+)and Cu^(2+)ion facilely

A novel Ni doped carbon quantum dots(Ni-CQDs)fluorescence probe was synthesized by facile electrolysis of monoatomic Ni dispersed porous carbon(Ni–N–C).The obtained Ni-CQDs showed a high quantum yield of 6.3%with the strongest excitation and emission peaks of 360 nm and 460 nm,and maintained over 90%of the maximum fluorescence intensity in a wide p H range of 3–12.The metal ions detectability of Ni-CQDs was enhanced by Ni doping and functional groups modification,and the rapid and selective detection of Fe^(3+)and Cu^(2+)ions was achieved with Ni-CQDs through dynamic and static quenching mechanism,respectively.On one hand,the energy band gap of Ni-CQDs was regulated by Ni doping,so that excited electrons in Ni-CQDs were able to transfer to Fe^(3+)easily.On the other hand,the abundant functional groups promoted the generation of static quenching complexation between Cu^(2+)and Ni-CQDs.In metal ions detection,the linear quantitation range of Fe^(3+)and Cu^(2+)were 100–1000μM(R^(2)=0.9955)and 300–900μM(R^(2)=0.9978),respectively.The limits of detection(LOD)were calculated as 10.17 and 7.88μM,respectively.Moreover,the fluorescence quenched by Cu^(2+)could be recovered by EDTA2-due to the destruction of the static quenching complexation.In this way,NiCQDs showed the ability to identify the two metal ions to a certain degree under the condition of Fe^(3+)and Cu^(2+)coexistent.This work paves the way of facile multiple metal ion detection with high sensitivity.

A Fluorescent Chemosensor for Dihydrogen Phosphate Ion Based on 2-[2-Hydroxy-4-(diethylamino)phenyl]-1Himidazo[4,5-b]phenazine-Fe^(3+)Ensemble

A long wavelength emission fluorescent(612 nm)chemosensor with high selectivity for H_(2)PO_(4)^(−)ions was designed and synthesized according to the excited state intramolecular proton transfer(ESIPT).The sensor can exist in two tautomeric forms(‘keto’and‘enol’)in the presence of Fe^(3+)ion,Fe^(3+)may bind with the‘keto’form of the sensor.Furthermore,the in situ generated GY-Fe^(3+)ensemble could recover the quenched fluorescence upon the addition of H_(2)PO_(4)^(−)anion resulting in an off-on-type sensing with a detection limit of micromolar range in the same medium,and other anions,including F^(−),Cl^(−),Br^(−),I^(−),AcO^(−),HSO^(−)_(4),ClO^(−)_(4)and CN−had nearly no influence on the probing behavior.The test strips based on 2-[2-hydroxy-4-(diethylamino)phenyl]-1H-imidazo[4,5-b]phenazine and Fe^(3+)metal complex(GY-Fe^(3+))were fabricated,which could act as convenient and efficient H_(2)PO_(4)^(−)test kits.

Highly Efficient AF@MOF-808 for the Selective Detection of Fe^(3+)Ions and Cr_(2)O_(7)^(2-)Anions from Aqueous Solution

AF@MOF-808 incorporating the acriflavine(AF)dye into the nanocages of MOF-808 was constructed by one-pot hydrothermal method,whose crystallization,morphology and stability were characterized by the X-ray powder diffractometer(XRD),scanning electron microscope(SEM)and thermogravimetric analysis(TGA).AF@MOF-808 exhibits bright green light emission with the high quantum yield of 38.27%and can selectively detect Fe^(3+)ion and Cr_(2)O_(7)^(2-)anion from 12 kinds of metal ions or anions in the aqueous solution.

A New Bio-metal-organic Framework:Synthesis,Crystal Structure and Selectively Sensing of Fe(Ⅲ)Ion in Aqueous Medium

A new two-dimensional(2D)bio-metal-organic framework based on trinuclear cluster units,[Zn_(3)(adeninate)_(2)(CH_(3)COO)_(4)]·DMF(Zn–A),was synthesized by the self-assembly of biomolecule adenines with zinc ions.Topological analysis reveals its 4^(4) connected layer structure.Remarkably,Zn–A bears high sensitivity and selectivity detection ability of iron ion with the limit of detection being 4.0×10^(-6) mol/L.

Novel LaFe_(2)O_(4)spinel structure with a large oxygen reduction response towards protonic ceramic fuel cell cathode

Highly active and stable electrocatalysts are mandatory for developing high-performance and longlasting fuel cells.The current study demonstrates a high oxygen reduction reaction(ORR)electrocatalytic activity of a novel spinel-structured LaFe_(2)O_(4)via a self-doping strategy.The LaFe_(2)O_(4)demonstrates excellent ORR activity in a protonic ceramic fuel cell(PCFC)at temperature range of 350-500℃.The high ORR activity of LaFe_(2)O_(4)is mainly attributed to the facile release of oxide and proton ions,and improved synergistic incorporation abilities associated with interplay of multivalent Fe^(3+)/Fe^(2+)and La^(3+)ions.Using LaFe_(2)O_(4)as cathode over proton conducting BaZr_(0.4)Ce_(0.4)Y_(0.2)O_(3)(BZCY)electrolyte,the fuel cell has delivered a high-power density of 806 mW/cm^(2)operating at 500℃.Different spectroscopic and calculations methods such as UV-visible,Raman,X-ray photoelectron spectroscopy and density functional theory(DFT)calculations were performed to screen the potential application of LaFe_(2)O_(4)as cathode.This study would help in developing functional cobalt-free ORR electrocatalysts for low temperature-PCFCs(LT-PCFCs)and solid oxide fuel cells(SOFCs)applications.

Two Coordination Polymers with High Selectivity for Sensing Iron(Ⅲ) Constructed from Bifunctional Ligand

A new ligand [1-{2-(2-pyridyl)-benzo[d]imidazole}-2-(5-hydroxyisophthalic acid) ethane] was used to synthesize cadmium and cobalt based florescent organic frameworks successfully under solvothermal conditions. Single-crystal X-ray crystallography of both complexes as well as their thermal stability and luminescence properties was investigated. Much emphasis was placed on the newly synthesized Cd-complex which shows great sensitivity for the detection of Fe^(3+) ions and could be used as a potential probe to detect the Fe^(3+) ions.