查看更多>>摘要：Benefiting from their large molar extinction coefficient,high carrier mobility,narrow and tunable emissions,inorganic metal halide perovskites(IMHPs)demonstrate great potential in various opto-electrical devices including solar cells,light emitting diodes and photodetectors in the past few years.Metal ions doping,well-known as a modification method of semiconductors,has been extensively applied in IMHPs as well.Diverse metal ions have been doped in IMHPs including alkali metals,alkali earth metals,transition metals and lanthanide metals,which either improve their optical performances or induce intriguing brand-new properties.Among them,lanthanide metals feature plentiful energy levels and stable optical properties and are one of the most noteworthy species.Here we review recent progress in lanthanide ions doped IMHPs.We summarize Yb,Eu or Er ions singly doping in detail,which was the most investigated species in IMHPs.Other lanthanide ions are also reviewed synoptically.Furthermore,we introduce lanthanide ions multi-doped IMHPs and at last we put forward several po-tential development directions.As the interests in lanthanide ions doped IMHPs rise,researchers have made some achievements in the field.Still though,there are more unexplored issues.Although there are review articles focusing on metal ions doped IMHPs or lanthanide ions doped perovskites,this review aims to provide an overall introduction of lanthanide ions doped IMHPs.This review may help re-searchers learn about lanthanide ions doped IMHPs and is to inspire researchers to make further pro-motion in this field.
查看更多>>摘要：Two europium-bearing organic frameworks,termed as EuTPO-1 and EuTPO-2(H3TPO=tris(4-carboxylphenyl)-phosphineoxide),are reported in this work.A series of characterizations of EuTPO-1 and EuTPO-2,such as X-ray crystallography and photoluminescence spectroscopy,was performed to expatiate their structure and physicochemical properties.Both of them are constructed by dimers of the europium-oxygen subunit of[Eu2O16]and TPO molecule.Benefiting from high X-ray stopping attenua-tion and excellent luminescence efficiency,they emit sufficient luminescence when irradiated with X-rays.Meanwhile,they possess stable light outputs when exposed to high humidities and strong radiation dose,outperforming the commercial scintillator CsI:Tl.This result paves the way for developing new scintillator and enriches the compound of europium-bearing organic framework with X-ray scintillating luminescence.
查看更多>>摘要：Chemotherapy,the use of antitumor drugs to kill cancer cells,is currently one of the most effective treatments for cancer.However,serious toxic side effects caused by long-term drug accumulation can cause significant damage to the body,which limits the clinical application of antitumor drugs.In this study,a novel RENPs@DOX-Fe nanoprobe(NP)was constructed by coating the surface of rare earth nanomaterials(NaLuF4∶Yb,Er)with a complex formed by doxorubicin(DOX)and iron ion(Ⅲ).Due to the low toxicity of anthracycline-metal complexes,the damage to normal cells is reduced.The unique acidic microenvironment in tumor cells facilitates the decomposition and gradual release of DOX from the DOX-Fe complex.In addition,the DOX-Fe complex can convert near-infrared(NIR)light into heat en-ergy,which promotes the decomposition of the complex,further enhancing the release of DOX in the tumor environment.The change of ratio fluorescence of rare earth nanomaterials at 660 and 1550 nm after DOX release enables visual monitoring of drug release,which can potentially improve the chemotherapeutic effect.In vitro experiments established that RENPs@DOX-Fe NPs with NIR illumination had good therapeutic efficacy in tumors.This work provides new insights into designing tumor microenvironment-responsive nanoprobes for chemotherapy with minimal side effects.
查看更多>>摘要：In this paper,a series of GdOF-based green phosphors doped with Ho3+and Yb3+ions was prepared by a simple co-precipitation method.The crystal structures and optical properties were investigated in detail.The intensity of the emission of GdOF:Yb3+,Ho3+phosphors is enhanced by the effective energy transfer from Yb3+to Ho3+,and the optimal luminescence is achieved with the Ho3+doping amount of 0.1 mol％as well as Yb3+doping amount of 5 mol％.Tunable UC emission of samples is achieved by adjusting the doping concentration of Ho3+or Yb3+.The purity of the green UC emission is further improved by enhancing the excitation pumping power.In addition,logarithmic functions of green,red and near-infrared radiation intensities were calculated versus logarithmic function of pump power for further study.A possible UC luminescence mechanism between Yb3+and Ho3+is discussed based on power-dependent UC luminescence spectrum and decay lifetimes.These results suggest that GdOF∶Yb3+,Ho3+phosphors with bright and high-purity green UC emission have potential applications in the fields of bioimaging,display and illumination.
查看更多>>摘要：Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO4:Er3+/Tm3+/Yb3+materials exhibit excellent photo-chromism and multicolor upconversion properties from green,red to near infrared(NIR)emissions with increasing Yb concentrations.Reversible multiband upconversion modulations are achieved by alter-nating light(365 and 405 nm)or thermal stimuli.After 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21％(green),82.12％(red)and 77.38％(NIR)in the Y0.83Er0.01Tm0.01NbO4∶0.15 Yb sample.Besides,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide tem-perature range of 298-718 K.These results indicate that the Er3+/Tm3+/Yb3+tri-doped YNbO4 materials can be a good candidate in optical switching and data storage applications.
查看更多>>摘要：The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination chemistry.Benefiting from the unique luminescent and magnetic properties of lanthanide ions,the potential applications of lanthanide-organic cages in biological imaging applications are promising,but only a few corresponding explorations have been reported.Herein,we introduced a series of lanthanide tetrahedral cages,(EunGd4-nL4)(sol)8(n=0,1,2,3 and 4,where L=(4,4',4"-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine,and sol=dimethyl sulfoxide and methanol),with potential applications in biological imaging.Given the good luminescent and magnetic properties of Eu3+and Gd3+ions,Eu4L4 and Gd4L4 complexes show a high luminescence quantum yield of 29％in DMSO and large longitudinal relaxivity(r1)of 11.4(mmol/L)-1/s at 0.5 T in water containing 1 vol％DMSO,respectively.The heterobimetallic Eu-Gd complexes achieve a dual imaging mode by combining lumi-nescent and magnetic centers in one cage.When the Gd:Eu ratio increases from 1∶3 to 3∶1,the r1 values increases from 5.33 to 8.64(mmol/L)-1/s,higher than that of commercial contrast agent Gd-DOTA(3.23(mmol/L)-1/s).Owing to their low toxicity and good cell imaging ability toward ECA 109 cells,the self-assembled Eu-Gd heterobimetallic tetrahedral cages could be potential candidates for the multimodal imaging contrast agent.
查看更多>>摘要：Four rare earth inorganic-organic hybrid compounds based on Keggin-type polyoxometalate {SiW12}with general formula[{RE(DMF)4(H2O)4RE(DMF)6}2{SiW12O40}3](RE=La(1),Pr(2),Sm(3),Eu(4),DMF=N,N-dimethylformamide)were synthesized by the conventional solution method.Structure analyses indicate that four compounds are isostructural and are all built from three[SiW12O40]4-pol-yoxoanions and DMF ligands linked by RE3+.Compounds 1-4 are extremely sensitive to UV light and present excellent photochromic properties,in which the coloring and fading time of samples are both no more than 2 min,and the reversible coloring-fading process can be repeated for at least 10 cycles with little fatigue,suggesting that compounds 1-4 can be a series of fast-responsive and durable photo-chromic materials.Moreover,the solid-state photoluminescence spectra of compounds 3(Sm)and 4(Eu)display strong characteristic emissions of rare earth ions based on f-f transitions.Meanwhile,compound 4(Eu)has a longer fluorescence lifetime up to 566.74 μs.Notably,compounds 3(Sm)and 4(Eu)exhibit the switchable luminescence behavior induced by photochromism,which allows them to be used as po-tential molecular switches.
查看更多>>摘要：Luminescent hydrogels have received considerable attention in the application of sensors.Nitroaromatics are harmful to human health and can be carcinogenic.Some skin allergies and central nervous system injuries may also be attributed to the over exposure to nitroaromatics.Thus,nitroaromatics sensor with fast detection and low detection limit is highly desirable.Herein,novel tough hydrogels were prepared by introducing hydrogen bonds and covalent bonds into the interpenetrating networks of modified chitosan and poly(vinyl alcohol)(PVA)via frozen-thawing induced chemical cross-linking.The synthe-sized hydrogels exhibit high mechanical strength(0.23 MPa tensile strength at 140％tensile strain,1.0 MPa compressive strength at 80％compressive strain).Strong green emission was realized by energy transfer from the modified chitosan to Tb3+via the so-called"antenna effect."The prepared luminescent hydrogels show an excellent detection effect on nitroaromatic compounds and its detection limit can reach ppm-level.The hydrogels also exhibit good reversibility and a fast"off-on"fluorescence switching process.This work may open up a new way for the development of stable,rapid,and reusable sensors for the detection of harmful nitroaromatics.
查看更多>>摘要：A novel tetra-nuclear Tb-organic network,named as[Tb4(2-pyia)6(HAc)0.5(2,2'-bipy)(H2O)4.5]·2,2'-bipy·H2O(1),was synthesized hydrothermally based on 5-(pyridin-2-ylmethoxy)isophthalic acid(H2pyia)and 2,2'-bipyridine(2,2'-bipy)ligands,and characterized by single crystal X-ray diffraction,thermogravimetric(TG)analyses,powder X-ray diffraction(PXRD)and infrared(IR)technology.1 pos-sesses a two-dimensional network based on the tetra-nuclear inorganic building units,and theππstacking interactions between the pyia2-ligands and the guest 2,2'-bipy molecules play an important role in the forming of 3D supramolecular structure.1 exhibits excellent fluorescent sensing performance for Fe3+(1.26 × 10-8 mol/L),Cr2O72-(8.1 × 10-7 mol/L),2,4,6-trinitrophenol(TNP)(2.71 × 10-8 mol/L)and tetracycline(TCT)(2.76 × 10-7 mol/L)in aqueous solution with lower detection concentrations.The sensing mechanisms of 1 were investigated by density functional theory(DFT)calculations,ultraviolet-visible(UV-Vis)diffuse reflectance spectroscopy,PXRD and fluorescent lifetime analyses.The activated product of 1 was prepared by heating at 255 ℃ under constant pressure and used to photo-catalytically degrade TCT.Both 1 and the activated one have good photocatalytic degradation performance for TCT with degradation rates of 84.29％and 96.07％,respectively.The photocatalytic mechanisms were discovered by UV-Vis diffuse reflectance spectroscopy and radical trap experiments.The Tb-organic framework might be an excellent multifunctional fluorescent sensor and a good photocatalytic agent for TCT degradation in the future.
Nicolas Perciani de MoraesMaitê Birkett de Campos SanmartinRobson da Silva RochaAbner de Siervo...
314-322页
查看更多>>摘要：This paper aims to create visible light driven ternary photocatalysts using zinc oxide(ZnO),cerium(Ⅳ)oxide(CeO2),and carbon xerogel(CX)as constituent materials.The use of CeO2 is based on the creation of direct-Z-scheme heterojunctions with the ZnO and the consequent diminishing of charge recombi-nation,whereas the carbon xerogel inclusion is predicted to minimize bandgap energy,decrease electron-hole recombination,and boost specific surface area.Furthermore,the choice of the black-wattle tannin as a carbonaceous precursor was targeted at the development of an environmentally friendly and affordable composite.The existence of the hexagonal phase of zinc oxide and cubic structure of the cerium(Ⅳ)oxide in the ternary material was confirmed by X-ray diffractometry and X-ray photoelectron spectroscopy,with the latter also suggesting chemical bonding between the ZnO and the CX due to the creation of zinc oxycarbide complexes.The inclusion of the carbon xerogel provokes a significant modification in the morphology of the ternary material,resulting in an increased surface area and smaller particle aggregates.The CX/ZnO-CeO2 ternary composite obtains the highest photocatalytic efficiency among all the materials studied,degrading 100％of 4-chlorophenol under simulated sunlight and 68％under visible radiation,after 5 h.The increased photocatalytic activity can be attributed to the formation of direct Z-scheme heterojunctions between the semiconductors,higher visible light response,and higher specific surface area,as evidenced by the results obtained by active radical scavenging,chronoamperometry,diffuse reflectance spectroscopy,and N2 adsorption-desorption isotherms.
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