Co-reporter:Yan Gao, Feng Huang, Hang Lin, Ju Xu, Yuansheng Wang
Sensors and Actuators B: Chemical 2017 Volume 243() pp:137-143
Publication Date(Web):May 2017
DOI:10.1016/j.snb.2016.11.143
•Pr:Na2La2Ti3O10 is explored to be a very promising optical thermometric materials.•Temperature sensing mechanism for this material is revealed relating to Pr-Ti IVCT.•A novel thermometric strategy utilizing IVCT interfered Pr3+ emission is proposed.•This strategy is universally valid for other Pr doped oxides with suitable IVCT.In this study, the Ruddlesden-Popper type perovskite Na2La1.96Pr0.04Ti3O10 micro-crystals are synthesized and demonstrated to be one of the most promising optical temperature sensing materials. The measured maximal absolute temperature sensitivity of this phosphor reaches as high as 0.40 K−1, remarkably superior to those of the inorganic optical thermometric materials reported previously; while the relative sensitivity is 1.96% K−1, ranking among the highest ones for the inorganic optical thermometric materials. Analysis of the configurational coordinate diagram indicates that thermo-induced relaxation between the Pr3+ 3Px and 1D2 levels through Pr3+-Ti4+ intervalence charge transfer state is the primary cause for the temperature sensing characteristics. Based on these results, a novel temperature sensing strategy utilizing the intervalence charge transfer state interfered Pr3+ luminescence to perform optical thermometry is proposed, which is further demonstrated to be universally valid for the Pr3+ doped oxides containing d0 configured transition metal ions, as long as energy of the intervalence charge transfer state is moderate. This work may provide useful inspiration for developing high sensitive optical thermometric materials.Ruddlesden-Popper type perovskite Na2La1.96Pr0.04Ti3O10 is explored to be one of the most promising optical temperature sensing materials. The mechanism of its optical temperature sensing property is revealed by the configurational coordinate analysis. Sequentially, a novel temperature sensing strategy is proposed, and demonstrated to be universally valid for some Pr3+ doped oxides.
Co-reporter:Wenjuan Zhu;Dr. Feng Huang;Erxia Chen;Dr. Qingping Wu;Ju Xu; Canzhong Lu; Yuansheng Wang
Chemistry – An Asian Journal 2017 Volume 12(Issue 5) pp:524-529
Publication Date(Web):2017/03/02
DOI:10.1002/asia.201601519
AbstractGroup IVB ions (Ti4+ and Zr4+) are employed to modify solution growth of W18O49 nanocrystals. In the presence of group IVB ions, the morphology of the produced monoclinic W18O49 nanocrystals can be modulated from inhomogeneous shapes to uniform an ultrathin nanobelt with the ( 01) lattice plane being the main exposure surface. Interestingly, the ultrathin W18O49 nanobelts exhibit a unique chemical activity against alkylamine radicals, probably originated from the highly increased exposure of the ( 01) plane with extra tungsten and oxygen atoms inserted in the regular lattice, which makes this nanomaterial an active photocatalyst for the N-de-ethylation reaction of the rhodamine B molecules, as well as a promising gas sensor matrix with selective responses to alkylamine molecules, including diethylamine, dimethylamine, triethylamine and trimethylamine. These results could provide useful inspiration for developing other functional nanomaterials with technical significance via modification of their morphologies and chemical properties.
Co-reporter:Yan Gao;Hang Lin;Jiangcong Zhou;Ju Xu;Yuansheng Wang
Advanced Functional Materials 2016 Volume 26( Issue 18) pp:3139-3145
Publication Date(Web):
DOI:10.1002/adfm.201505332
In this work, a novel thermometry strategy based on the diversity in thermal quenching behavior of two intervalence charge transfer (IVCT) states in oxide crystals is proposed, which provides a promising route to design self-referencing optical temperature sensing material with superior temperature sensitivity and signal discriminability. Following this strategy, uniform Tb3+/Pr3+:NaGd(MoO4)2 micro-octahedrons are directionally synthesized. Originated from the diverse thermal responses between Tb3+-Mo6+ and Pr3+-Mo6+ IVCT states, fluorescence intensity ratio of Pr3+ to Tb3+ in this material displays excellent temperature sensing property in a temperature range from 303 to 483 K. The maximum absolute and relative sensitivity reaches as high as 0.097 K−1 and 2.05% K−1, respectively, being much higher than those of the previously reported optical thermometric materials. Excellent temperature sensing features are also demonstrated in the other Tb3+/Pr3+ codoped oxide crystals having d0 electron configured transition metal ions (Ti4+, V5+, Mo6+, or W6+), such as scheelite NaLu(MoO4)2 and NaLu(WO4)2, and monazite LaVO4 and perovskite La2Ti3O9, evidencing the universal validity of the proposed strategy. This work exploits an effective pathway for developing new optical temperature sensing materials with high performance.
Co-reporter:Jiangcong Zhou, Feng Huang, Hang Lin, Zebin Lin, Ju Xu and Yuansheng Wang
Journal of Materials Chemistry A 2016 vol. 4(Issue 32) pp:7601-7606
Publication Date(Web):22 Jul 2016
DOI:10.1039/C6TC02405J
In this work, inorganic perovskite CsPbBr3−xIx (x = 0–3) quantum dots (QDs) were synthesized, and their luminescence properties were studied. The optimized CsPbBrI2 QDs were chosen as red-emitting components to modify Ce3+:YAG-based white LEDs (WLEDs), which exhibit promising performance with a luminous efficacy (LE) of 58 lm W−1, a correlated color temperature (CCT) of 5907 K, and a color rendering index (CRI) of 90, at an operation current of 20 mA. More importantly, optical performance of the CsPbBrI2 QD-modified WLEDs do not exhibit serious degeneration when the operational current increases to as high as 350 mA, being obviously superior to most of the chalcogenide QD-assisted phosphor-converted WLEDs reported previously. These results indicate that the CsPbBr3−xIx QDs are promising red phosphors for high-power WLEDs.
Co-reporter:Jiangcong Zhou, Feng Huang, Ju Xu, Hui Chen and Yuansheng Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 13) pp:3023-3028
Publication Date(Web):02 Feb 2015
DOI:10.1039/C4TC02783C
A novel Sr3La(VO4)3 phosphor is explored which exhibits the bright self-activated luminescence and the ability to sensitize emission of rare earth activators, under the excitation of near UV light. The self-activated emission of the Sr3La(VO4)3 host is peaked at 520 nm with a broad emission band ranging from 400 nm to 700 nm, ascribing to the charge transfer in (VO4)3− groups; while the Sr3La(VO4)3:Eu3+ phosphors show both the broad band luminescence of (VO4)3− groups and the sharp peak emissions of Eu3+ ions. Through doping concentration optimization, intense warm white light is achieved under near UV excitation, with a quantum yield of 31.2%. This phosphor is therefore potentially applicable in near UV chip excited white LEDs.
Co-reporter:Jiangcong Zhou;Dr. Feng Huang;Ju Xu ; Yuansheng Wang
Chemistry – An Asian Journal 2014 Volume 9( Issue 11) pp:3287-3290
Publication Date(Web):
DOI:10.1002/asia.201402729
Abstract
A mild three-step solution strategy is developed to prepare AgMS (M=Zn, Cd) nanoheterostructures composed of MS nanorods with silver tips. First, Ag2SMS heterostructures are synthesized by following a solution–liquid–solid mechanism with Ag2S nanoparticles as catalysts, then the Ag2S sections of the heterostructures are converted into silver nanoparticles by selective extraction of sulfur. Notably, for the prepared AgCdS heterostructures, the localized surface plasmon resonance of silver remarkably intensifies the photoluminescence of CdS by enhancing the excitation light absorption, which is beneficial for potential applications of CdS nanoparticles in the fields of biolabeling, light-emitting diodes, and so forth. The strategy reported herein would be useful for designing and fabricating other metal–semiconductor hybrid nanostructures with desirable performances.
Co-reporter:Jiangcong Zhou, Feng Huang, Ju Xu and Yuansheng Wang
Nanoscale 2013 vol. 5(Issue 20) pp:9714-9719
Publication Date(Web):14 Aug 2013
DOI:10.1039/C3NR03601D
Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se–CdSe and Ag2Se–ZnSe, and even multi-segment heterostructures such as Ag2Se–CdSe–ZnSe and Ag2Se–ZnSe–CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.
Co-reporter:Jiangcong Zhou, Feng Huang, Ju Xu and Yuansheng Wang
CrystEngComm 2013 vol. 15(Issue 21) pp:4217-4220
Publication Date(Web):26 Mar 2013
DOI:10.1039/C3CE00015J
Cu1.94S–MnS dimeric nanoheterostructures are fabricated by employing Cu1.94S nanoplates as precursors. By managing the heterogrowth of MnS, the localized surface plasmon resonance wavelength of Cu1.94S can be optimized to 1323 nm, which makes this nanoheterostructure applicable as a light absorbing agent for photothermal therapy. Meanwhile, Mn2+ ions enable the nanoheterostructures to exhibit paramagnetic behavior at room temperature, indicating their possible application as a magnetic contrast agent for magnetic resonant imaging. This kind of bifunctional material is a potential candidate for the so-called “theranostic agent”, which is of great significance in biomedical application.
Co-reporter:Jiangcong Zhou, Feng Huang, Ju Xu, Hui Chen and Yuansheng Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 13) pp:NaN3028-3028
Publication Date(Web):2015/02/02
DOI:10.1039/C4TC02783C
A novel Sr3La(VO4)3 phosphor is explored which exhibits the bright self-activated luminescence and the ability to sensitize emission of rare earth activators, under the excitation of near UV light. The self-activated emission of the Sr3La(VO4)3 host is peaked at 520 nm with a broad emission band ranging from 400 nm to 700 nm, ascribing to the charge transfer in (VO4)3− groups; while the Sr3La(VO4)3:Eu3+ phosphors show both the broad band luminescence of (VO4)3− groups and the sharp peak emissions of Eu3+ ions. Through doping concentration optimization, intense warm white light is achieved under near UV excitation, with a quantum yield of 31.2%. This phosphor is therefore potentially applicable in near UV chip excited white LEDs.
Co-reporter:Jiangcong Zhou, Feng Huang, Hang Lin, Zebin Lin, Ju Xu and Yuansheng Wang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 32) pp:NaN7606-7606
Publication Date(Web):2016/07/22
DOI:10.1039/C6TC02405J
In this work, inorganic perovskite CsPbBr3−xIx (x = 0–3) quantum dots (QDs) were synthesized, and their luminescence properties were studied. The optimized CsPbBrI2 QDs were chosen as red-emitting components to modify Ce3+:YAG-based white LEDs (WLEDs), which exhibit promising performance with a luminous efficacy (LE) of 58 lm W−1, a correlated color temperature (CCT) of 5907 K, and a color rendering index (CRI) of 90, at an operation current of 20 mA. More importantly, optical performance of the CsPbBrI2 QD-modified WLEDs do not exhibit serious degeneration when the operational current increases to as high as 350 mA, being obviously superior to most of the chalcogenide QD-assisted phosphor-converted WLEDs reported previously. These results indicate that the CsPbBr3−xIx QDs are promising red phosphors for high-power WLEDs.
