Chiral phosphorescent materials have received extensive research owing to the unique properties of optical activity in recent years.Many phosphorescent carbon dots(CDs)materials have been reported,but the research on ...Chiral phosphorescent materials have received extensive research owing to the unique properties of optical activity in recent years.Many phosphorescent carbon dots(CDs)materials have been reported,but the research on chiral phosphorescence is still in the exploratory stage.This work designs multi-color room temperature phosphorescent(RTP)CDs with chiral signals,which are fully mixed with aromatic aldehyde precursors and chiral amino compounds precursors in a boric acid(BA)matrix and can be easily prepared by solvent-free thermal method.The prepared(R)-GCDs,(R)-YCDs and(R)-RCDs achieved phosphorescence emission at 545 nm,582 nm,and 654 nm,respectively,and exhibited corresponding circular dichroism(CD)signals at 341 nm,394 nm,384 nm,and 380 nm,448 nm,and 435 nm,respectively.The longest phosphorescence lifetime is up to 946 ms.Specifically,YCDs exhibit time-dependent phosphorescence under UV excitation,and the afterglow time under white light excitation can reach 40 s.This article provides a new approach to the study of chiral phosphorescence.展开更多
Multicolor phosphors that respond rapidly to external stimuli are highly desirable for many applications, including lighting,optical displays and sensors. Herein, spiropyran(SP)-functionalized carbon dots(CDs) were sy...Multicolor phosphors that respond rapidly to external stimuli are highly desirable for many applications, including lighting,optical displays and sensors. Herein, spiropyran(SP)-functionalized carbon dots(CDs) were synthesized with a broad-spectrum output that were responsive to both ultraviolet(UV)/visible light and pH. The SP-CDs possessed strong ester linkages between the UV-absorbing/blue-emitting CDs and blue-absorbing/red-emitting surface SP groups, allowing efficient F?rster resonance energy transfer(FRET) between the donor and acceptor. UV irradiation or acid addition cause the SP ring opening to merocyanine(MC) or protonated MCH+forms, respectively, together with the formation of sheet-like aggregates. These processes enhanced the red emissions by the SP groups and attenuated blue emissions from the CDs. These changes were fully reversible under visible light or basic conditions, respectively, allowing dynamic regulation of the fluorescence properties(emission colors from blue to red, photoluminescence(PL) intensity) under photoirradiation on the timescale of minutes. As proof-of concept, we demonstrate that the emission properties of the SP-CDs can be used to construct UV and pH sensing materials as well as light emitting diode(LED) with different colors.展开更多
基金supported by the National Natural Science Foundation of China(52122308,52103239,and 22371110).
文摘Chiral phosphorescent materials have received extensive research owing to the unique properties of optical activity in recent years.Many phosphorescent carbon dots(CDs)materials have been reported,but the research on chiral phosphorescence is still in the exploratory stage.This work designs multi-color room temperature phosphorescent(RTP)CDs with chiral signals,which are fully mixed with aromatic aldehyde precursors and chiral amino compounds precursors in a boric acid(BA)matrix and can be easily prepared by solvent-free thermal method.The prepared(R)-GCDs,(R)-YCDs and(R)-RCDs achieved phosphorescence emission at 545 nm,582 nm,and 654 nm,respectively,and exhibited corresponding circular dichroism(CD)signals at 341 nm,394 nm,384 nm,and 380 nm,448 nm,and 435 nm,respectively.The longest phosphorescence lifetime is up to 946 ms.Specifically,YCDs exhibit time-dependent phosphorescence under UV excitation,and the afterglow time under white light excitation can reach 40 s.This article provides a new approach to the study of chiral phosphorescence.
基金supported by the National Natural Science Foundation of China(52122308,21905253,51973200,52103239)the Natural Science Foundation of Henan(202300410372)+2 种基金Henan Postdoctoral Foundationfunding support from the MacDiarmid Institute for Advanced MaterialsNanotechnology and the Dodd-Walls Centre for Photonic and Quantum Technologies。
文摘Multicolor phosphors that respond rapidly to external stimuli are highly desirable for many applications, including lighting,optical displays and sensors. Herein, spiropyran(SP)-functionalized carbon dots(CDs) were synthesized with a broad-spectrum output that were responsive to both ultraviolet(UV)/visible light and pH. The SP-CDs possessed strong ester linkages between the UV-absorbing/blue-emitting CDs and blue-absorbing/red-emitting surface SP groups, allowing efficient F?rster resonance energy transfer(FRET) between the donor and acceptor. UV irradiation or acid addition cause the SP ring opening to merocyanine(MC) or protonated MCH+forms, respectively, together with the formation of sheet-like aggregates. These processes enhanced the red emissions by the SP groups and attenuated blue emissions from the CDs. These changes were fully reversible under visible light or basic conditions, respectively, allowing dynamic regulation of the fluorescence properties(emission colors from blue to red, photoluminescence(PL) intensity) under photoirradiation on the timescale of minutes. As proof-of concept, we demonstrate that the emission properties of the SP-CDs can be used to construct UV and pH sensing materials as well as light emitting diode(LED) with different colors.
