This paper reports that hexagonal-phase LaF3：Yb0.20^3＋,Er0.02^3＋ and LaF3：Yb0.20^3＋, Tm0.02^3＋ nanocrystals （NCs） were synthesized via a hydrothermal method. The transmission electron microscopy, selected are...This paper reports that hexagonal-phase LaF3：Yb0.20^3＋,Er0.02^3＋ and LaF3：Yb0.20^3＋, Tm0.02^3＋ nanocrystals （NCs） were synthesized via a hydrothermal method. The transmission electron microscopy, selected area electron diffraction, powder x-ray diffraction, and thermogravimetric analysis are used to characterize the NCs. Under 980 nm excitation, the Yb^3＋/Er^3＋ and Yb^3＋/Tm^3＋ codoped NCs colloidal solutions present bright green and blue upconversion fluorescence, respectively. These NCs show efficient infrared-to-violet and infrared-to-visible upconversion. The upconversion fluo- rescence mechanisms of LaF2：Yb0.20^3＋, Er0.02^3＋ and LaF3：Yb0.20^3＋,Tm0.02^3＋ NCs are investigated with a 980-nm diode laser as excitation source.展开更多
The design of the photocatalytic materials has made a great of remarkable progress in the area of the enhancement photocatalytic activity,but there are still lots of problems such as wide band gap,low utilization of s...The design of the photocatalytic materials has made a great of remarkable progress in the area of the enhancement photocatalytic activity,but there are still lots of problems such as wide band gap,low utilization of sunlight,low quantum efficiency and poor stability,which further limit the extensive practical applications.Thus,it is a hot research topic and key scientific problem to be solved that how to design and prepare the catalysts,which can respond to visible and near-infrared light in sunlight.Inspired by efficient nonlinear optical upconversion materials,upconversion-based nanocomposites can indirectly broaden the absorption ranges of semiconductors by co nverting the captured long-band visible and near-infrared incident light into high-energy short-band visible or ultraviolet light,which can be adopted as the promising candidate in wide-spectral-light-activating photocatalytic materials coupling with conventional semiconductors.According to our recent works and literature reports,recent review summarizes the research progress of photocatalytic materials with upconversion effect on photolysis of water for hydrogen production,degradation of organic and inorganic pollutants,reduction of CO_(2) and photodynamic therapy.The prepared nanocomposites can suppress the recombination of electrons and holes,and greatly improve the photocatalytic efficiency by the synergistic effect.It maybe stimulates a great interest in rational design and preparation of efficient full-spectrum photocatalytic systems and their wide application in solar energy conversion.展开更多
Zinc phthalocyanines(ZnPc)are widely recognized as efficient triplet photosensitizers in photodynamic therapy and photocatalysis,owing to their intense absorption in the visible range and long triplet-state lifetimes....Zinc phthalocyanines(ZnPc)are widely recognized as efficient triplet photosensitizers in photodynamic therapy and photocatalysis,owing to their intense absorption in the visible range and long triplet-state lifetimes.However,their application in triplet-triplet annihilation(TTA)upconversion is lacking to date.In this study,we synthesized a new ZnPc photosensitizer,4I-ZnPc,and composed a TTA upconversion system using rubrene as the energy acceptor.Upon photoexcitation at 663 nm,yellow fluorescence from rubrene was observed in deoxygenated dichloromethane,demonstrating TTA upconversion with an anti-Stokes shift of 0.331 eV and a quantum yield of 1.82%(out of the 50%maximum).Using nanosecond transient absorption spectroscopy,we determined the triplet lifetime of 4I-ZnPc,the triplet-triplet energy transfer efficiency,and the fluorescence quantum yield.These measurements provide critical insights into the photophysical processes governing the TTA upconversion system.Our results highlight the potential advantages and limitations of ZnPc as a triplet photosensitizer for TTA upconversion.展开更多
In this paper, the Au nanoparticles and rare-earth （RE） upconversion nanoparticles （NPs） were respectively synthesized by using polyelectrolyte as the capping agents. Since the synthesized Au NPs and RE NPs had th...In this paper, the Au nanoparticles and rare-earth （RE） upconversion nanoparticles （NPs） were respectively synthesized by using polyelectrolyte as the capping agents. Since the synthesized Au NPs and RE NPs had the similar size and surface conditions, Their mixture were employed in a pH sensing application. Benefited from the good spectral overlap between the RE upconversion emission bands and pH-tunable surface plasmon bands of the Au NPs, the pH-induced manipulation of green-to-red emission intensity ratio of the upconversion fluorescence was achieved in the Au-RE mixture. The results demonstrate a rapid ratiometric approach for pH sensing, which is more efficient than traditional sensing methods that depend on single intensity-based responses to analytes.展开更多
In this work, a simple method to modulate the crystal phase and morphology with a large amount of K＋ions codoping is proposed. The phase changes to the mixture of β-Na YF4 and β-KYF4 with increasing the content of...In this work, a simple method to modulate the crystal phase and morphology with a large amount of K＋ions codoping is proposed. The phase changes to the mixture of β-Na YF4 and β-KYF4 with increasing the content of K^＋ions to 80 mol%.When it exceeds 80 mol%, β-Na YF4 disappears gradually and β-KYF4 dominates with a poor crystalline. In addition, the morphology changes from nanosphere to nanoplate, and then to nanoprism, which indicates that a higher content of K^＋ions favors the growth rates along [0001] than the [10-10] of the nanocrystals. Additionally, the upconversion（UC） luminescence properties and the ratio of red/green（R/G） UC intensity of samples with different phases and morphologies are detected,which makes it possible to tune the UC fluorescence by varying the concentration of K^＋ions.展开更多
Rare earth nanomaterials exhibit remarkable characteristics,including real-time responsiveness,luminescence stability,and multicolor emission capabilities.Herein,NaYbF_(4):x%Tb,y%Eu@NaYF_(4)core-shell structured nanop...Rare earth nanomaterials exhibit remarkable characteristics,including real-time responsiveness,luminescence stability,and multicolor emission capabilities.Herein,NaYbF_(4):x%Tb,y%Eu@NaYF_(4)core-shell structured nanoparticles(CSNP)were synthesized with distinct fluorescence under both ultraviolet(UV)and near-infrared(NIR)excitation.It can be uniformly mixed with a transparent ink solution and loaded into ink cartridges to print customized graphics on copy papers.The graphics cannot be recognized under normal visible light,and the concealed information with high resolution can only be exposed under specific excitation light.Combining with cryptography,it facilitates the implementation of advanced information encryption techniques.Consequently,the innovative fluorescent ink materials hold significant promise for enhancing anti-counterfeiting and information encryption.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos 10474096 and 50672030)
文摘This paper reports that hexagonal-phase LaF3：Yb0.20^3＋,Er0.02^3＋ and LaF3：Yb0.20^3＋, Tm0.02^3＋ nanocrystals （NCs） were synthesized via a hydrothermal method. The transmission electron microscopy, selected area electron diffraction, powder x-ray diffraction, and thermogravimetric analysis are used to characterize the NCs. Under 980 nm excitation, the Yb^3＋/Er^3＋ and Yb^3＋/Tm^3＋ codoped NCs colloidal solutions present bright green and blue upconversion fluorescence, respectively. These NCs show efficient infrared-to-violet and infrared-to-visible upconversion. The upconversion fluo- rescence mechanisms of LaF2：Yb0.20^3＋, Er0.02^3＋ and LaF3：Yb0.20^3＋,Tm0.02^3＋ NCs are investigated with a 980-nm diode laser as excitation source.
基金Project supported by the National Natural Science Foundation of China(21962006,21707055,21872030)Youth Key Project of Jiangxi Province Natural Science Foundation(20192ACBL21011)+6 种基金Program of Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology(3401223429)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2019)Guangdong Basic and Applied Basic Research Foundation(2019A1515011249)Key Research Project of Natural Science of Guangdong Provincial Department of Education(2019)Jiangxi Province Natural Science Foundation(20181BAB213010)Open Fund of Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control(2018B030322017)Open Fund for Key Laboratory of Green Energy and Environmental Catalysis in Universities of Fujian Province(FJ-GEEC201901)。
文摘The design of the photocatalytic materials has made a great of remarkable progress in the area of the enhancement photocatalytic activity,but there are still lots of problems such as wide band gap,low utilization of sunlight,low quantum efficiency and poor stability,which further limit the extensive practical applications.Thus,it is a hot research topic and key scientific problem to be solved that how to design and prepare the catalysts,which can respond to visible and near-infrared light in sunlight.Inspired by efficient nonlinear optical upconversion materials,upconversion-based nanocomposites can indirectly broaden the absorption ranges of semiconductors by co nverting the captured long-band visible and near-infrared incident light into high-energy short-band visible or ultraviolet light,which can be adopted as the promising candidate in wide-spectral-light-activating photocatalytic materials coupling with conventional semiconductors.According to our recent works and literature reports,recent review summarizes the research progress of photocatalytic materials with upconversion effect on photolysis of water for hydrogen production,degradation of organic and inorganic pollutants,reduction of CO_(2) and photodynamic therapy.The prepared nanocomposites can suppress the recombination of electrons and holes,and greatly improve the photocatalytic efficiency by the synergistic effect.It maybe stimulates a great interest in rational design and preparation of efficient full-spectrum photocatalytic systems and their wide application in solar energy conversion.
基金supported by the National Natural Science Foundation of China(Nos.22473104 and 22403086)support of the China Postdoctoral Science Foundation(No.2023M733378).
文摘Zinc phthalocyanines(ZnPc)are widely recognized as efficient triplet photosensitizers in photodynamic therapy and photocatalysis,owing to their intense absorption in the visible range and long triplet-state lifetimes.However,their application in triplet-triplet annihilation(TTA)upconversion is lacking to date.In this study,we synthesized a new ZnPc photosensitizer,4I-ZnPc,and composed a TTA upconversion system using rubrene as the energy acceptor.Upon photoexcitation at 663 nm,yellow fluorescence from rubrene was observed in deoxygenated dichloromethane,demonstrating TTA upconversion with an anti-Stokes shift of 0.331 eV and a quantum yield of 1.82%(out of the 50%maximum).Using nanosecond transient absorption spectroscopy,we determined the triplet lifetime of 4I-ZnPc,the triplet-triplet energy transfer efficiency,and the fluorescence quantum yield.These measurements provide critical insights into the photophysical processes governing the TTA upconversion system.Our results highlight the potential advantages and limitations of ZnPc as a triplet photosensitizer for TTA upconversion.
基金Supported by grants from the Natural Science Foundation of Jiangsu Province(SBK201240182)the Natural Science Foundation of China(J1210061)
文摘In this paper, the Au nanoparticles and rare-earth （RE） upconversion nanoparticles （NPs） were respectively synthesized by using polyelectrolyte as the capping agents. Since the synthesized Au NPs and RE NPs had the similar size and surface conditions, Their mixture were employed in a pH sensing application. Benefited from the good spectral overlap between the RE upconversion emission bands and pH-tunable surface plasmon bands of the Au NPs, the pH-induced manipulation of green-to-red emission intensity ratio of the upconversion fluorescence was achieved in the Au-RE mixture. The results demonstrate a rapid ratiometric approach for pH sensing, which is more efficient than traditional sensing methods that depend on single intensity-based responses to analytes.
基金supported by the National High Technology Research and Development Program of China(Grant No.2013AA032205)the National Natural Science Foundation of China(Grant No.51272022)the Fundamental Research Funds for the Central Universities,China(Grant No.2012JBZ001)
文摘In this work, a simple method to modulate the crystal phase and morphology with a large amount of K＋ions codoping is proposed. The phase changes to the mixture of β-Na YF4 and β-KYF4 with increasing the content of K^＋ions to 80 mol%.When it exceeds 80 mol%, β-Na YF4 disappears gradually and β-KYF4 dominates with a poor crystalline. In addition, the morphology changes from nanosphere to nanoplate, and then to nanoprism, which indicates that a higher content of K^＋ions favors the growth rates along [0001] than the [10-10] of the nanocrystals. Additionally, the upconversion（UC） luminescence properties and the ratio of red/green（R/G） UC intensity of samples with different phases and morphologies are detected,which makes it possible to tune the UC fluorescence by varying the concentration of K^＋ions.
基金supported by the National Natural Science Foundation of China(Nos.22101257 and 52103189)Foundation of Zhejiang Sci-Tech University Shengzhou Innovation Research Institute(No.SYY2024B000001).
文摘Rare earth nanomaterials exhibit remarkable characteristics,including real-time responsiveness,luminescence stability,and multicolor emission capabilities.Herein,NaYbF_(4):x%Tb,y%Eu@NaYF_(4)core-shell structured nanoparticles(CSNP)were synthesized with distinct fluorescence under both ultraviolet(UV)and near-infrared(NIR)excitation.It can be uniformly mixed with a transparent ink solution and loaded into ink cartridges to print customized graphics on copy papers.The graphics cannot be recognized under normal visible light,and the concealed information with high resolution can only be exposed under specific excitation light.Combining with cryptography,it facilitates the implementation of advanced information encryption techniques.Consequently,the innovative fluorescent ink materials hold significant promise for enhancing anti-counterfeiting and information encryption.
