The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and e...The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and electrical advantages. However,it is very sensitive to the surrounding oxygen and moisture, which limits its development seriously. It is urgent to spare no effort to enhance its optical and electrical stability for further application. In this paper, we synthesize the MAPbI_(3) perovskite film on the glass substrate with/without the ionic liquid(IL) of 1-Butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_(4)) by a simple two-step sequential solution method. The additive of BMIMBF_(4)can improve the quality of crystal structure. Moreover, the photo-luminescence(PL) intensity of MAPbI_(3) film with BMIMBF_(4) is much stronger than the pure MAPbI_(3) film after a week in the air, which is almost ten-fold of the pure one. Meanwhile, under the illumination of 405-nm continuous wave(CW) laser, the fluorescent duration of the MAPbI_(3) film with BMIMBF_(4) is approximately 2.75 min, while the pure MAPbI;film is only about 6 s. In fact, ionic liquid of BMIMBF_(4) in the perovskite film plays a role of passivation, which prevents the dissolution of MAPbI_(3) into CH_(3)NH_(3)and PbI_(2) and thus enhances the stability of environment. In addition, the ionic liquid of BMIMBF;possesses high ionic conductivity, which accelerates the electron transport, so it is beneficial for the perovskite film in the areas of solar cells, photodetectors, and lasers. This interesting experiment provides a promising way to develop the perovskite’s further application.展开更多
A series of europium(III) complexes with different chain length, tris [2-m-pyridylmethanamido-5-phenyl- (1,3,4)-oxadiazole] mono [2-(4-n-alkylphenyl)-iminazole (4,5-f)-1,10-phenanthroline] Eu(III) [Eu(PMA)3Nn (n = 6, ...A series of europium(III) complexes with different chain length, tris [2-m-pyridylmethanamido-5-phenyl- (1,3,4)-oxadiazole] mono [2-(4-n-alkylphenyl)-iminazole (4,5-f)-1,10-phenanthroline] Eu(III) [Eu(PMA)3Nn (n = 6, 10, 14,18)] were synthesized. All of these amphiphilic europium(III) complexes could form stable Langmuir film at air/water interface and could be transferred onto hydrophilic quartz and mica substrates by measurement of UV spectra in which the absorbance of the LB films at about 288 nm scales showed the linearity with the number of layers deposited. In order to investigate relation between fluorescence properties and the arrangement of molecular in LB films, surface topography of monolayer films were observed by atomic force microscopy (AFM). Results showed that the emission spectra have Eu(III) characteristic peaks and strong emission strength. It is interesting that the molecular with looser arrangement in LB films has better monochromacity, which illustrated that energy might transferred more easily from ligand to Eu(III) in loosen structure films.展开更多
The high amount of l-lysine can increase the potential risk of cardiovascular disease.Additionally,2-methoxy benzaldehyde(2-MB)has high toxicity and can easily pollute the environment.In this work,carbon quantum dots(...The high amount of l-lysine can increase the potential risk of cardiovascular disease.Additionally,2-methoxy benzaldehyde(2-MB)has high toxicity and can easily pollute the environment.In this work,carbon quantum dots(CQDs)can be encapsulated into Eu-BTB(H_(3)BTB=1,3,5-tri(4-carboxyphenyl)benzene),forming the multi-emission composite material Eu-BTB@CQDs.It has two emissions peaks(617 nm for Eu and 470 nm for CQDs).Eu-BTB@CQDs can be applied as bi-functional ratiometric“off&on”luminescent sensor for l-lysine and 2-MB with high sensitivity and selectivity,the low limit of detection(LOD)for l-lysine is 3.68μmol/L and for 2-MB is 0.54μmol/L,respectively.Additionally,Eu-BTB@CQDs can quantitatively discriminate l-lysine in the mixed d-and l-lysine water solutions(five different concentrations ratio of l/d-lysine has been set)makes the chiral detection of l-lysine are more meaningful.On the other hand,Eu-BTB@CQDs also can detect 2-MB over 4-methoxybenzaldehyde(4-MB)with high selectivity.Further the detection of 2-MB and l-lysine in the lake water real samples with the reasonable recovery rate.Finally,the detection mechanisms for l-lysine and 2-MB were also investigated and discussed in detail.展开更多
A series of samarium(Sm)doped hydroxyapatites containing strontium(Sr)with controllable and adjustable luminescence were designed and prepared via chemical hydrolysis co-precipitation method.The effects of doping conc...A series of samarium(Sm)doped hydroxyapatites containing strontium(Sr)with controllable and adjustable luminescence were designed and prepared via chemical hydrolysis co-precipitation method.The effects of doping concentration of Sm on the structure,composition,photoluminescence(PL),energy transfer,substitute site,fluoresce lifetime and luminescence color of samples were investigated.It is shown that the introduction of Sr ions induces the structure and composition change for Sm doped samples.The typical transitions of Sm^(3+) at 564,601,648 and 707 nm due to^(4)G_(5/2)→^(6)H_(J/2)(J=5,7,9 and 11)transition under the excitation of 404 nm were detected.The PL intensity is affected by the Sr/Ca ratio and Sm concentration,and the optimal concentration of Sm is 0.8 mol%when Sr/Ca ratio equals 7/3.The non-radiative transitions and energy transfer of Sm ions are the main reason for the quenching,and the interactions among ions are ascribed to dipole-dipole type by theoretical calculation.Besides,the ratio of PL intensity between 601 and 648 nm(r_(O/R)=I_(601nm)/I_(648nm))indicates the symmetry and substitution process of Sm ions to Ca/Sr ions.The fluorescence lifetime(τ)decreases with the concentration of Sm increasing,which is the result of the decrease of distance and the enhanced interaction between Sm ions.The CIE chromaticity coordinates and luminescence color of samples are in the orange-red region and have close relation with the concentration of Sm.Furthermore,the cytotoxicity evaluation and confocal laser scanning microscopy(CLSM)observation of samples via cells indicate the good biocompatibility and safe use of this kind of bio-based luminescent materials for their potential efficient fluorescence labeling and detection.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant No. 2018YFC2001100)the Natural National Science Foundation of China (Grant No. 61574017)+1 种基金the Fundamental Research Funds for Central Universities, China (Grant No. 2017CX10007)the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University (Grant No. 2020GXYSOF08)。
文摘The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and electrical advantages. However,it is very sensitive to the surrounding oxygen and moisture, which limits its development seriously. It is urgent to spare no effort to enhance its optical and electrical stability for further application. In this paper, we synthesize the MAPbI_(3) perovskite film on the glass substrate with/without the ionic liquid(IL) of 1-Butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_(4)) by a simple two-step sequential solution method. The additive of BMIMBF_(4)can improve the quality of crystal structure. Moreover, the photo-luminescence(PL) intensity of MAPbI_(3) film with BMIMBF_(4) is much stronger than the pure MAPbI_(3) film after a week in the air, which is almost ten-fold of the pure one. Meanwhile, under the illumination of 405-nm continuous wave(CW) laser, the fluorescent duration of the MAPbI_(3) film with BMIMBF_(4) is approximately 2.75 min, while the pure MAPbI;film is only about 6 s. In fact, ionic liquid of BMIMBF_(4) in the perovskite film plays a role of passivation, which prevents the dissolution of MAPbI_(3) into CH_(3)NH_(3)and PbI_(2) and thus enhances the stability of environment. In addition, the ionic liquid of BMIMBF;possesses high ionic conductivity, which accelerates the electron transport, so it is beneficial for the perovskite film in the areas of solar cells, photodetectors, and lasers. This interesting experiment provides a promising way to develop the perovskite’s further application.
文摘A series of europium(III) complexes with different chain length, tris [2-m-pyridylmethanamido-5-phenyl- (1,3,4)-oxadiazole] mono [2-(4-n-alkylphenyl)-iminazole (4,5-f)-1,10-phenanthroline] Eu(III) [Eu(PMA)3Nn (n = 6, 10, 14,18)] were synthesized. All of these amphiphilic europium(III) complexes could form stable Langmuir film at air/water interface and could be transferred onto hydrophilic quartz and mica substrates by measurement of UV spectra in which the absorbance of the LB films at about 288 nm scales showed the linearity with the number of layers deposited. In order to investigate relation between fluorescence properties and the arrangement of molecular in LB films, surface topography of monolayer films were observed by atomic force microscopy (AFM). Results showed that the emission spectra have Eu(III) characteristic peaks and strong emission strength. It is interesting that the molecular with looser arrangement in LB films has better monochromacity, which illustrated that energy might transferred more easily from ligand to Eu(III) in loosen structure films.
基金supported financially by Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2019ZD15).
文摘The high amount of l-lysine can increase the potential risk of cardiovascular disease.Additionally,2-methoxy benzaldehyde(2-MB)has high toxicity and can easily pollute the environment.In this work,carbon quantum dots(CQDs)can be encapsulated into Eu-BTB(H_(3)BTB=1,3,5-tri(4-carboxyphenyl)benzene),forming the multi-emission composite material Eu-BTB@CQDs.It has two emissions peaks(617 nm for Eu and 470 nm for CQDs).Eu-BTB@CQDs can be applied as bi-functional ratiometric“off&on”luminescent sensor for l-lysine and 2-MB with high sensitivity and selectivity,the low limit of detection(LOD)for l-lysine is 3.68μmol/L and for 2-MB is 0.54μmol/L,respectively.Additionally,Eu-BTB@CQDs can quantitatively discriminate l-lysine in the mixed d-and l-lysine water solutions(five different concentrations ratio of l/d-lysine has been set)makes the chiral detection of l-lysine are more meaningful.On the other hand,Eu-BTB@CQDs also can detect 2-MB over 4-methoxybenzaldehyde(4-MB)with high selectivity.Further the detection of 2-MB and l-lysine in the lake water real samples with the reasonable recovery rate.Finally,the detection mechanisms for l-lysine and 2-MB were also investigated and discussed in detail.
基金Project supported by the National Natural Science Foundation of China(51972201)International Science and Technology Cooperation of Science and Technology Department of Shaanxi Province of China(2017KW-024)。
文摘A series of samarium(Sm)doped hydroxyapatites containing strontium(Sr)with controllable and adjustable luminescence were designed and prepared via chemical hydrolysis co-precipitation method.The effects of doping concentration of Sm on the structure,composition,photoluminescence(PL),energy transfer,substitute site,fluoresce lifetime and luminescence color of samples were investigated.It is shown that the introduction of Sr ions induces the structure and composition change for Sm doped samples.The typical transitions of Sm^(3+) at 564,601,648 and 707 nm due to^(4)G_(5/2)→^(6)H_(J/2)(J=5,7,9 and 11)transition under the excitation of 404 nm were detected.The PL intensity is affected by the Sr/Ca ratio and Sm concentration,and the optimal concentration of Sm is 0.8 mol%when Sr/Ca ratio equals 7/3.The non-radiative transitions and energy transfer of Sm ions are the main reason for the quenching,and the interactions among ions are ascribed to dipole-dipole type by theoretical calculation.Besides,the ratio of PL intensity between 601 and 648 nm(r_(O/R)=I_(601nm)/I_(648nm))indicates the symmetry and substitution process of Sm ions to Ca/Sr ions.The fluorescence lifetime(τ)decreases with the concentration of Sm increasing,which is the result of the decrease of distance and the enhanced interaction between Sm ions.The CIE chromaticity coordinates and luminescence color of samples are in the orange-red region and have close relation with the concentration of Sm.Furthermore,the cytotoxicity evaluation and confocal laser scanning microscopy(CLSM)observation of samples via cells indicate the good biocompatibility and safe use of this kind of bio-based luminescent materials for their potential efficient fluorescence labeling and detection.
