Three bis-vinylpyridine compounds (4,4′-bis(2-vinylpyridine)biphenyl L1,4,4′-bis(3-vinylpyridine) biphenyl L2,and 4,4′-bis (4-vinylpyridine)biphenyl L3) were synthesized by one-step solid-state reactions at room te...Three bis-vinylpyridine compounds (4,4′-bis(2-vinylpyridine)biphenyl L1,4,4′-bis(3-vinylpyridine) biphenyl L2,and 4,4′-bis (4-vinylpyridine)biphenyl L3) were synthesized by one-step solid-state reactions at room temperature,giving nearly quantitative yields. The compounds obtained were fully characterized by IR,MS and NMR spectroscopies. The structures of L2 and L3 were determined by single crystal X-ray diffraction analysis. No noticeable solvatochromism was observed in either one-photon absorption or one-photon excited fluorescence spectra. All of the compounds have high fluorescence quantum yields and long fluorescence lifetime. The linear and nonlinear optical properties of the compounds were investigated both experimentally and theoretically. Interestingly,the position of the nitrogen atom from pyridine influences their two-photon absorption across-sections.展开更多
Two novel terpyridine-based chromophores with D-A (D = donor, A = acceptor) structural model containing modified triphenylamine moiety (L1 and L2 ) have been conveniently synthesized via formylation and reduction in s...Two novel terpyridine-based chromophores with D-A (D = donor, A = acceptor) structural model containing modified triphenylamine moiety (L1 and L2 ) have been conveniently synthesized via formylation and reduction in satisfactory yields, and fully characterized. The single crystals of them were obtained and determined by X-ray diffraction analysis. The relationships between structure and photophysical properties of the two chromophores were investigated both experimentally and theoretically. The measured maximum TPA cross-sections per molecular weight (δmax /MW) of the chromophores are 0.63 GM/(g mol) (L1) and 0.72 GM/(g mol) (L2), respectively, in DMF as a high polar solvent. The results indicate that the value of δmax/MW could be well tuned by the intramolecular charge transfer (ICT), which could be realized by introducing additional elecron-donor/acceptor groups.展开更多
Herein,we report a three-dimensional porous TiO_(2)/Fe_(2)TiO_(5)/Fe_(2)O_(3)(TFF)inverse opal through in situ thermal solid reactions for photoelectrochemical water splitting.The Fe_(2)TiO_(5) interfacial layer withi...Herein,we report a three-dimensional porous TiO_(2)/Fe_(2)TiO_(5)/Fe_(2)O_(3)(TFF)inverse opal through in situ thermal solid reactions for photoelectrochemical water splitting.The Fe_(2)TiO_(5) interfacial layer within TFF acting as a bridge to tightly connect to TiO_(2) and Fe_(2)O_(3) reduces the interfacial charge transfer resistance,and suppresses the bulk carrier recombination.The optimized TFF displays a remarkable photocurrent density of 0.54mAcm^(-2) at 1.23V vs.reversible hydrogen electrode(RHE),which is 25 times higher than that of TiO_(2)/Fe_(2)O_(3)(TF)inverse opal(0.02mAcm^(-2) at 1.23V vs.RHE).The charge transfer rate in TFF inverse opal is 2-8 times higher than that of TF in the potential range of 0.7-1.5V vs.RHE.The effects of the Fe_(2)TiO_(5) interfacial layer are further revealed by X-ray absorption spectroscopy and intensity-modulated photocurrent spectroscopy.This work offers an interfacial engineering protocol to improve charge separation and transfer for efficient solar water splitting.展开更多
Tm^(3+) doped Na_5Lu_9F_(32) single crystal with high optical quality was grown by an improved Bridgman method. The Judd-Ofelt intensity parameters ?_t(t=2, 4, 6) were calculated according to the measured absorption s...Tm^(3+) doped Na_5Lu_9F_(32) single crystal with high optical quality was grown by an improved Bridgman method. The Judd-Ofelt intensity parameters ?_t(t=2, 4, 6) were calculated according to the measured absorption spectra and physical-chemical properties of the obtained Na_5Lu_9F_(32) single crystal. The stimulated emission cross-section of the ~3F_4→~3H_6 transition(～1.8 μm) is 0.35×10^(-20) cm^2 for Tm^(3+) doped Na_5Lu_9F_(32) single crystal. The emission spectra under the excitation of 790 nm laser diode(LD) and fluorescence lifetime at 1.8 μm were measured to reveal the fluorescence properties of Tm^(3+) doped Na_5Lu_9F_(32) single crystal. The research results show that the Tm^(3+) doped Na_5Lu_9F_(32) single crystal has larger stimulated emission cross-section compared with other crystals. All these spectral properties suggest that this kind of Tm^(3+)doped Na_5Lu_9F_(32) crystal with high physical-chemical stability and high-efficiency emission at 1.8 μm may be used as potential laser materials for optical devices.展开更多
基金supported by a grant for the National Natural Science Foundation of China (20771001, 50703001, 50873001)Department of Education of Anhui Province (KJ2010A030)+1 种基金Team for Scientific Innovation Foundation of Anhui Province (2006KJ007TD)Key Laboratory of Opto-Electronic Information Acquisition and Manipulation (Anhui University)
文摘Three bis-vinylpyridine compounds (4,4′-bis(2-vinylpyridine)biphenyl L1,4,4′-bis(3-vinylpyridine) biphenyl L2,and 4,4′-bis (4-vinylpyridine)biphenyl L3) were synthesized by one-step solid-state reactions at room temperature,giving nearly quantitative yields. The compounds obtained were fully characterized by IR,MS and NMR spectroscopies. The structures of L2 and L3 were determined by single crystal X-ray diffraction analysis. No noticeable solvatochromism was observed in either one-photon absorption or one-photon excited fluorescence spectra. All of the compounds have high fluorescence quantum yields and long fluorescence lifetime. The linear and nonlinear optical properties of the compounds were investigated both experimentally and theoretically. Interestingly,the position of the nitrogen atom from pyridine influences their two-photon absorption across-sections.
基金the National Natural Science Foundation of China (21071001, 51142011, 21271004, 21201005 and 21271003)Ministry of Education Funded Projects Focus on returned overseas scholarProgram for New Century Excellent Talents in University (China)
文摘Two novel terpyridine-based chromophores with D-A (D = donor, A = acceptor) structural model containing modified triphenylamine moiety (L1 and L2 ) have been conveniently synthesized via formylation and reduction in satisfactory yields, and fully characterized. The single crystals of them were obtained and determined by X-ray diffraction analysis. The relationships between structure and photophysical properties of the two chromophores were investigated both experimentally and theoretically. The measured maximum TPA cross-sections per molecular weight (δmax /MW) of the chromophores are 0.63 GM/(g mol) (L1) and 0.72 GM/(g mol) (L2), respectively, in DMF as a high polar solvent. The results indicate that the value of δmax/MW could be well tuned by the intramolecular charge transfer (ICT), which could be realized by introducing additional elecron-donor/acceptor groups.
基金supported by the National Natural Science Foundation of China(21771001 and 51872002)Anhui Provincial Natural Science Foundation(1708085ME120)+2 种基金the Program of Anhui Scientific and Technical Leaders Reserve Candidates(2018RH168)the Scholar Program for the Outstanding Innovative Talent of College Discipline(Specialty)the doctoral start-up fund and open fund for Discipline Construction,Institute of Physical Science and Information Technology,Anhui University.
文摘Herein,we report a three-dimensional porous TiO_(2)/Fe_(2)TiO_(5)/Fe_(2)O_(3)(TFF)inverse opal through in situ thermal solid reactions for photoelectrochemical water splitting.The Fe_(2)TiO_(5) interfacial layer within TFF acting as a bridge to tightly connect to TiO_(2) and Fe_(2)O_(3) reduces the interfacial charge transfer resistance,and suppresses the bulk carrier recombination.The optimized TFF displays a remarkable photocurrent density of 0.54mAcm^(-2) at 1.23V vs.reversible hydrogen electrode(RHE),which is 25 times higher than that of TiO_(2)/Fe_(2)O_(3)(TF)inverse opal(0.02mAcm^(-2) at 1.23V vs.RHE).The charge transfer rate in TFF inverse opal is 2-8 times higher than that of TF in the potential range of 0.7-1.5V vs.RHE.The effects of the Fe_(2)TiO_(5) interfacial layer are further revealed by X-ray absorption spectroscopy and intensity-modulated photocurrent spectroscopy.This work offers an interfacial engineering protocol to improve charge separation and transfer for efficient solar water splitting.
基金supported by the National Natural Science Foundation of China(Nos.51472125 and 51272109)the Natural Science Foundation of Zhejiang Province(No.LZ17E020001)K.C. Wong Magna Fund in Ningbo University
文摘Tm^(3+) doped Na_5Lu_9F_(32) single crystal with high optical quality was grown by an improved Bridgman method. The Judd-Ofelt intensity parameters ?_t(t=2, 4, 6) were calculated according to the measured absorption spectra and physical-chemical properties of the obtained Na_5Lu_9F_(32) single crystal. The stimulated emission cross-section of the ~3F_4→~3H_6 transition(～1.8 μm) is 0.35×10^(-20) cm^2 for Tm^(3+) doped Na_5Lu_9F_(32) single crystal. The emission spectra under the excitation of 790 nm laser diode(LD) and fluorescence lifetime at 1.8 μm were measured to reveal the fluorescence properties of Tm^(3+) doped Na_5Lu_9F_(32) single crystal. The research results show that the Tm^(3+) doped Na_5Lu_9F_(32) single crystal has larger stimulated emission cross-section compared with other crystals. All these spectral properties suggest that this kind of Tm^(3+)doped Na_5Lu_9F_(32) crystal with high physical-chemical stability and high-efficiency emission at 1.8 μm may be used as potential laser materials for optical devices.
