High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better ...High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better beneficiation index were gotten by direct reduction roasting with dephosphorization agent followed by two stages of grinding and magnetic separation. P content decreases from 0.82% in the raw ore to 0.06% in the magnetic concentrate, and the total iron grade increases from 43.65% to 90.23%, the recovery of iron can reach 87%. Mechanisms of phosphorus removal in the beneficiation of high phosphorous oolitic hematite ore by direct reduction roasting with dephosphorization agent were studied using XRD, SEM and EPMA. The results showed that about 20% of the apatite in the raw ore transferred into phosphorus and volatilized with the gas in the process of reduction roasting, while the rest 80% apatite was not involved in the reaction of generation of phosphorus, and remained as apatite in the roasted products, which was removed to tailings by grinding and magnetic separation. A small amount of phosphorus existed in the magnetic concentrate as apatite. The oolitic texture of raw ore was partly changed during roasting, resulting in the formation of nepheline in the reaction between the dephosphorization agent, SiO2 and Al2O3 in the raw ore, which greatly improved the liberation degree of minerals in the roasted products, and it was beneficial to the subsequent grinding and magnetic separation.展开更多
Commercial phosphor-converted white LEDs(pc-WLEDs)face two inherent limitations,namely blue light hazard and low color rendering index,due to the use of blue LEDs as excitation source.To address these challenges,viole...Commercial phosphor-converted white LEDs(pc-WLEDs)face two inherent limitations,namely blue light hazard and low color rendering index,due to the use of blue LEDs as excitation source.To address these challenges,violet LEDs are proposed as an alternative solution.Currently,phosphors that can be efficiently excited by violet light(with wavelengths from 400 to 420 nm)remain under development still.In this study,we utilize large language models to construct a comprehensive database of Eu^(2+)and Ce^(3+)doped phosphors for discovering novel violet-excited phosphors.A total of 822 phosphor data entries,including elemental compositions,crystal structures and excitation/emission wavelengths,have been extracted and validated from 9551 research papers.Compared with Ce^(3+)doped phosphors,the Eu^(2+)are in general more suited for violet-excited phosphors,as well as red-emitting phosphors.In particular,Eu^(2+)doped nitrides and sulfides are worth of exploration for violet-excited phosphors.This database is expected to be useful in the future development of phosphors for pc-WLEDs based on artificial intelligence methods.The datasets in this article are listed in Science Data Bank at http://doi.org/10.57760/sciencedb.34314.展开更多
Long-afterglow photocatalytic technology offers promising potential fo r all-weather pollutant treatment,yet its efficiency is often constrained by competition between afterglow emission and photocatalytic reactions.T...Long-afterglow photocatalytic technology offers promising potential fo r all-weather pollutant treatment,yet its efficiency is often constrained by competition between afterglow emission and photocatalytic reactions.To address this,we developed a Pr^(3+)-doped Ca_(2)Al_(2)SiO_(7)(CASO)photocatalyst enriched with oxygen vacancies(V_(O)).The introduction of oxygen vacancies significantly increases trap concentration,enhancing both the intensity and du ration of the afterglow emission.A persulfate-assisted photo-Fenton system was designed based on V_(O)-CASO:Pr^(3+)enabling the self-activated degradation of tetracycline hydrochloride(TC)under ultraviolet afterglow.The photo-Fenton reaction consumes excess holes accumulated during the afterglow process,improving carrier utilization efficiency and mitigating rapid recombination.Additionally,persulfate addition can enrich reactive species and facilitate the Fe^(2+)/Fe^(3+)cycle.Benefiting from these synergistic effects,V_(O)-CASO:Pr^(3+)has achieved 75%TC degradation within1 h,significantly outperforming traditional systems.This study provides a new strategy for enhancing long-afterglow photocatalytic performance,paving the way for sustainable pollutant degradation technologies.展开更多
Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications...Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications in other fields such as detection and sensing technologies,the Eu^(2+)emission needs to be tuned into the near-infrared region,but it is a big challenge to obtain Eu^(2+)near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting.In this work,we chose M_(4)Li(BN_(2))_(3)(M=Ca,Sr,Ba)as a host and realize the near-infrared region emission of Eu^(2+)in it.Among these phosphors,Ba4Li(BN_(2))_(3):Eu^(2+)exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation,while Ca_(4)Li(BN_(2))_(3):Eu^(2+)and Sr_(4)Li(BN_(2))_(3):Eu^(2+)emit at740 and 680 nm,respectively.We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu^(2+)in this system.展开更多
Although significant progress has been made in the development of red phosphors,the development of efficient and thermally stable red phosphors remains a challenge.In this paper,(Sr_(3-y)Cay)Ca_(1-x)Nb_(2)O_(9):xSm^(3...Although significant progress has been made in the development of red phosphors,the development of efficient and thermally stable red phosphors remains a challenge.In this paper,(Sr_(3-y)Cay)Ca_(1-x)Nb_(2)O_(9):xSm^(3+)phosphors with 648 nm red emission,which belongs to the ^(4)G_(5/2)→^(6)H_(9/2) leap of Sm^(3+)and is close to the absorption wavelengths of plant chloro phylls and photochromes PR,were prepared by the high-temperature solid-phase method.The lattice mismatch between Sm^(3+)and Ca^(2+)is solved by cation substitution,which increases the atomic disorder and lattice distortion,and the lattice distortion also causes the forbidden leap to be disrupted,thus improving the luminescence efficiency.Meanwhile,the substitution of small-radius cations leads to the enhancement of the structural rigidity of the material.The test results show that after the introduction of Ca^(2+),the luminous intensity of the phosphor is increased by 5.15 times,the quantum yield is increased from 22.89%to 48.31%,and the I_(423 K)/I_(298 K) value is increased from 70.7%to 73.4%,and the fluorescence lifetime is also improved accordingly.White light-emitting diodes(WLEDs)and fuchsia light-emitting diodes(LEDs)were successfully prepared using the experimentally prepared phosphors,demonstrating their great potential in the fields of optical thermometers,WLEDs and plant growth.展开更多
Five samples of LiMgPO_(4):Gd were prepared via five different production processes using a solid-state reaction method.The effects of the preparation process on optically stimulated luminescence(OSL)and thermolumines...Five samples of LiMgPO_(4):Gd were prepared via five different production processes using a solid-state reaction method.The effects of the preparation process on optically stimulated luminescence(OSL)and thermoluminescence(TL)were investigated.Considering its high sensitivity,low fading,and minimum detectable dose(MDD),the LiMgPO_(4):Gd phosphor heated to 900℃for 15 h is concluded to be optimal.The effects of annealing on the OSL sensitivity,relative residual OSL signals measured after 24 h of irradiation,and MDD of LiMgPO_(4):Gd phosphors heated to 900℃for 15 h were also investigated.Considering its high sensitivity,low fading,and MDD,annealing at 350℃for 1 h is concluded to be optimal.The OSL signal of LiMgPO_(4):Gd was derived from the principal TL glow peak.For a maximum integration time of 5 s,the OSL signal was stable,with no fading 30 days after irradiation.LiMgPO_(4):Gd eliminated approximately 2.2%of the OSL signal at each readout for a readout time of 0.1 s,which is sufficient for fast and multiple OSL readout.The sensitivity of LiMgPO_(4):Gd phosphor,annealed for 1 h at 350℃with a reading time of 0.1 s,was found to be approximately 98%of that observed forα-Al_(2)O_(3):C(TLD-500k),which should be sufficient for low-dose measurements in personal,workplace,and environmental dosimetry.展开更多
Heat-induced emission peak shift(HIEPS),encompassing both redshift and blueshift,remains mechanistically unresolved in phosphor materials.Using state-of-the-art first-principles calculations of M_(2)SiO_(4):Eu^(2+)(M=...Heat-induced emission peak shift(HIEPS),encompassing both redshift and blueshift,remains mechanistically unresolved in phosphor materials.Using state-of-the-art first-principles calculations of M_(2)SiO_(4):Eu^(2+)(M=Sr,Ba,Ca),we reveal that conventional thermal expansion theory cannot adequately explain these phenomena.Instead,our frozen phonon analysis identifies local electron-phonon coupling as the dominant mechanism,where anisotropic thermal vibrations selectively distort the asymmetric Eu-5d potential well that arises from the dopant’s coordination environment.This distortion manifests through the temperature-sensitiveΔ_(f−d) parameter governing the 5d→4f transition energy,directly controlling spectral shifts.Our findings establish a universal framework for HIEPS in rare-earth phosphors and enable a Δ_(f−d)-guided strategy for designing thermally stable phosphors.展开更多
Curing temperature significantly affects the pozzolanic reaction kinetics of phosphorous slag(PS),thereby governing the early-age(7 d)hydration behavior of PS composite binders at 20,30,and 60℃.The Krstulovic-Dabic k...Curing temperature significantly affects the pozzolanic reaction kinetics of phosphorous slag(PS),thereby governing the early-age(7 d)hydration behavior of PS composite binders at 20,30,and 60℃.The Krstulovic-Dabic kinetic model was applied to identify three characteristic processes:nucleation and growth(NG),phase boundary interaction(I),and diffusion(D).Control mixtures containing inert quartz powder with comparable particle size distributions were prepared for comparison.Pore characteristics of hardened PS pastes at different temperatures were analyzed via mercury intrusion porosimetry,while hydration products were characterized using X-ray diffraction(XRD)and thermogravimetric analysis(TG-DTG).The experimental results indicate that the retarding effect of PS on early cement hydration outweighs its accelerating effect,attributed to the combined influence of nucleation and dilution,with retardation decreasing as temperature increases.PS exhibits early reactivity and continuously consumes calcium hydroxide through the pozzolanic reaction,as evidenced by stable phase assemblages accompanied by reduced CH content in XRD and TG-DTG analyses.At 20℃,increasing PS content maintains the NG→I→D mechanism but slows reaction rates across all stages.Elevated temperatures significantly accelerate the NG process,shifting the dominant mechanism from NG toward D.Simultaneously,enhanced PS reactivity contributes to a refined pore structure and improved compressive strength.展开更多
Sodium-ion batteries(SIBs) are promising electrochemical energy storage systems as lithium-ion batteries by virtue of their similar chemical properties and natural abundance and availability.However,the ionic radius o...Sodium-ion batteries(SIBs) are promising electrochemical energy storage systems as lithium-ion batteries by virtue of their similar chemical properties and natural abundance and availability.However,the ionic radius of Na^(+)is larger than that of Li^(+),leading to challenges in its insertion/extraction at anode side.As a class of anode materials,phosphorus allotropes(PAs,red,and black) and metal phosphides(MPs) have shown great prospects because of high theoretical gravimetric/volumetric capacity,high carrier mobility,and suitable redox potential.In this review,recent developments in the studies of PAs and MPs with particular emphasis on understanding sodium storage mechanisms,developing novel synthesis strategies,and performance validations have been manifested valuable solutions to address these challenges.We begin with the introduction and classification of the macroscopic sodiation mechanisms of PAs and MPs,and the various fabrication strategies of PAs and MPs are comprehensively summarized in second section.The third section thoroughly reviews the progresses on PAs and MPs-based advanced materials for their application in SIBs.Finally,we also discuss the significant challenges and outline a roadmap for future research directions.展开更多
To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the character...To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the characteristics of low-tempe rature sulfuric acid deco mposition.When a single monazite was leached using 75 wt% H_(2)SO_(4) solution with phosphoric acid,the size and number of monazite particles in the washing slag gradually decrease with the increase in phosphoric acid content in the leaching solution.The monazite phase can hardly be found in the slag when the phosphoric acid content reaches 70 g/L,which indicates that phosphoric acid is favorable for monazite decomposition.The mixed rare earth concentrate was leached by 75 wt% H_(2)SO_(4) containing 70 g/L phosphoric acid,the mineral compositions of the washing slag are only gypsum and unwashed rare earth sulfuric acid.After cyclic leaching of75 wt% H_(2)SO_(4),the mineral compositions of the primary leaching washing slag are mainly undecomposed monazite,rare earth sulfate and calcium sulfate.However,monazite is not found in the mineral phase of the second and third leaching washing slag.The leaching rates of rare earth and phosphorus gradually increase with the increase in cyclic leaching times.In addition,the phosphoric acid content in the leaching solution increases with the increase in the number of cyclic leaching time.However,the rising trend decreases when the phosphoric acid content reaches 50 g/L by adsorption and crystallization of phosphoric acid.A small amount of water can be used to clean the leaching residue before washing to recover the more soluble phosphorus acid according to the difference of dissolution between phosphoric acid and rare earth sulfuric acid.展开更多
Different reactive flame retardants have been extensively developed for vinyl ester resins(VERs),but very few of them can yield a flame-retardant resin that meets defined standards(e.g.UL-94 V-0 rating).In this work,p...Different reactive flame retardants have been extensively developed for vinyl ester resins(VERs),but very few of them can yield a flame-retardant resin that meets defined standards(e.g.UL-94 V-0 rating).In this work,phosphorous-containing 1-vinylimidazole salts(called VIDHP and VIDPP)were synthesized through the facile neutralization of the acid and 1-vinylimidazole.VIDHP and VIDPP were then applied as flame-retardant crosslinking agents of VERs,by which phosphorus-containing groups could be incorporated into the resin chain via ionic bonds.VIDHP/VER and VIDPP/VER showed a high curing activity and can be well cured in moderate temperatures.With 20 wt.%additions of VIDHP and VIDPP,VIDHP20/VER,and VIDPP20/VER presented a limiting oxygen index value of 29.7%and 28.4%,respectively,with the latter achieving a UL 94 V0 rating.In the cone calorimetric test,compared to the unmodified VERs,VIDPP20/VER exhibited large reductions in the peak heat release rate,total heat release rate,and total smoke release rate while VIDHP20/VER demonstrated comparatively inferior performance in terms of the heat release.VIDHP20/VER and VIDPP20/VER showed good thermal stability and presented a little lower glass transition temperature than the control sample.VIDPP with a low phosphorus oxidation state(+1)demonstrated high flame-retardant activities in the gaseous phase,whereas VIDHP with a high phosphorus oxidation state(+5)primarily exhibited efficacy in the condensed phase.展开更多
Inorganic lead-free double perovskites have the advantages of low toxicity,broadband emission,and good stability,which make them promising luminescent materials for lighting applications.However,due to the limited reg...Inorganic lead-free double perovskites have the advantages of low toxicity,broadband emission,and good stability,which make them promising luminescent materials for lighting applications.However,due to the limited regulation of their self-trapped exciton emission,it is still greatly challenging to achieve white light emitting from a single double perovskite host.Herein,efficient and tunable white light is realized in Cs_(2)NalnCl_(6)∶Sb^(3+),Tb^(3+),Sm^(3+)double perovskite by controlling the ratios of the doped three ions with blue,green,and red emissions,respectively.The steady-state and transient fluorescence spectra of singly-and doubly-doped double perovskites reveal the existence of multiple energy transfer channels in the triply-doped phosphors,including from Sb^(3+)to Tb^(3+),Sb^(3+)to Sm^(3+),and Tb^(3+)to Sm^(3+).Benefiting from these channels,the color coordinates of the triply-doped phosphors can cross the whole white light area of the CIE chromaticity diagram by adjusting the ratios of the three dopants,and the maximum internal quantum yield of the white light phosphors is 66.61%.The white emission phosphors show the characteristic of being independent of excitation wavelength within 310-360 nm.Furthermore,the emission intensity at 430 K of the white light phosphor Cs_(2)NalnCl_(6)∶0.01Sb^(3+),0.65Tb^(3+),0.20Sm^(3+)remains 50% of that at room temperature.A WLED device fabricated with the phosphor and a 365 nm LED chip exhibits a high color rendering index of 90.9,correlated color temperature of 5469 K,and CIE coordinates of(0.333 and 0.328).The results indicate that the as-prepared double perovskite materials are promising candidates in the solid-state lighting field.展开更多
To optimize the comprehensive properties of Ni−Si precipitation strengthened phosphor bronze,the impact of the Ni/Si mass ratio and heat treatment process on a Cu−8Sn−0.1P−1Ni−xSi alloy was explored.High resolution fi...To optimize the comprehensive properties of Ni−Si precipitation strengthened phosphor bronze,the impact of the Ni/Si mass ratio and heat treatment process on a Cu−8Sn−0.1P−1Ni−xSi alloy was explored.High resolution field emission scanning electron microscopy and transmission electron microscopy were used for microstructural characterization.The results indicate that the properties are influenced by the Ni/Si mass ratio,attributed to the formation of various second phases.Simultaneously,by influencing the diffusion rate,the microstructures and properties are influenced by the solid solution treatment.The strength is enhanced by precipitated nanoscale particles during the aging process by influencing the motion of dislocations.Ultimately,excellent comprehensive properties,including ultimate tensile strength,yield strength,and elongation of 866 MPa,772 MPa,and 8.7%,respectively,are obtained in the Cu−8Sn−0.1P−1Ni−0.227Si alloy.展开更多
The catalytic enantioselective electrophilic amination reaction has emerged as a highly efficient method for synthesizing diverse nitrogen-containing chiral molecules,with the development of various asymmetric catalys...The catalytic enantioselective electrophilic amination reaction has emerged as a highly efficient method for synthesizing diverse nitrogen-containing chiral molecules,with the development of various asymmetric catalysis systems.Chiral phosphoric acids(CPA)have been widely acknowledged as versatile chiral organocatalysts since it was first discovered in 2004,finding application in catalyzing diverse asymmetric reactions.A comprehensive overview of recent advances in CPA-catalyzed asymmetric electrophilic amination reactions using different N-electrophilic reagents,including azo reagents,aryldiazonium salts,and imine derivatives,is presented.Furthermore,insights into future developments in this field are offered.展开更多
Broadband near-infrared(NIR)phosphor-conve rted light-emitting diode(pc-LED)is a new generation of light source for spectroscopy applications.Current studies generate a broad continuous NIR spectrum to promise the det...Broadband near-infrared(NIR)phosphor-conve rted light-emitting diode(pc-LED)is a new generation of light source for spectroscopy applications.Current studies generate a broad continuous NIR spectrum to promise the detection of a wide range of substances.This paper reports a discontinuous NIR spectral distribution peaking at 760 and 1400 nm,respectively,by co-doping Cr^(3+)and Ni^(2+)ions into CaLu_(2)Mg_(2)Si_(3)O_(12)garnet.The benefit of such a discontinuous spectrum is its ability to prevent energy waste in specific applications,such as moisture(freshness)and hemoglobin detection,where only spectral bands near 750 and 1500 nm are required.The discontinuous spectrum is attributed to the ene rgy transfer from Cr^(3+)to Ni^(2+)ions.The NIR pc-LED fabricated by the new phosphor shows photoelectric efficiency of 9.12%@10 mA and NIR output power of 11.44 mW@100 mA.The NIR pc-LED also performs well when measuring alcohol solution where only a discontinuous spectrum is needed.These results highlight the potential of NIR phosphors with a discontinuous spectrum across a broad 700-1600 nm range.展开更多
Bifunctional applications in solid state lighting and optical thermometry are attractive in the optical field.Despite Eu^(3+)doped phosphors are widely used in white-LEDs,phosphors with high temperature sensitivity re...Bifunctional applications in solid state lighting and optical thermometry are attractive in the optical field.Despite Eu^(3+)doped phosphors are widely used in white-LEDs,phosphors with high temperature sensitivity remain rare.Herein,NaLnTe_(2)O_(7):Eu^(3+)(Ln=Y and Gd)phosphors were synthesized using a rapid microwave-assisted solidstate(MASS)method to fulfill these applications.Under 395 nm excitation,NaLnTe_(2)O_(7):Eu^(3+)exhibit the characteristic ^(5)D_(0)→^(7)F_(J)(J=1–4)transitions of Eu^(3+).Substituting Gd^(3+) for Y^(3+) enhances the luminescence by approximately 2.42 times.Structural analyses reveal that the improved luminescent properties are attributed to the more distorted and appropriate coordination environment in NaGdTe_(2)O_(7):Eu^(3+).Finally,white-LEDs using NaGdTe_(2)O_(7):Eu^(3+)as the red-component produce white light with high Ra of 89.Furthermore,the distinct thermal responses of the ^(5)D_(0)→^(7)F_(J) transitions enable NaLnTe_(2)O_(7):Eu^(3+)to function as temperature sensors via fluorescence intensity ratio(FIR)strategy.NaYTe_(2)O_(7):Eu^(3+)possesses the maximum relative/absolute sensitivity of 1.45%/15.93%K^(-1),whereas NaGdTe_(2)O_(7):Eu^(3+)achieves the maximum relative/absolute sensitivity of 1.53%/30.24% K^(-1).This work highlights the significance of cationic substitution in enhancing luminescent properties for multifunctional applications.展开更多
To develop efficient luminescence and optical thermometry materials for color display and non-contact temperature measurement,novel RE^(3+)(RE=Eu,Sm)doped self-activated Na_(2)LuMg_(2)V_(3)O_(12)phosphors were prepare...To develop efficient luminescence and optical thermometry materials for color display and non-contact temperature measurement,novel RE^(3+)(RE=Eu,Sm)doped self-activated Na_(2)LuMg_(2)V_(3)O_(12)phosphors were prepared by a typical solid-state reaction method.Their crystal structure,morphology,multi-color luminescence and temperature sensing properties were elaborately investigated.Under UV light excitation,an intense and broad green-yellow emission band from VO_(4)^(3-)group is observed in the Na_(2)LuMg_(2)V_(3)O_(12)matrix,indicating its potential application in solid state lighting.After the incorpo ration of Eu^(3+)and Sm^(3+)ions,efficient energy transfer(ET)from VO_(4)^(3-)group to Eu^(3+)/Sm^(3+)ions occurs and the emission color of the samples can be readily tuned among different color ranges.Besides,based on the change of luminescence intensity and lifetimes of VO_(4)^(3-)group in Na_(2)LuMg_(2)V_(3)O_(12):Eu^(3+)and Na_(2)LuMg_(2)V_(3)O_(12):Sm^(3+),the ET efficiency was analyzed and the mechanism is illustrated.Finally,large discrepancy between the thermal stability of VO_(4)^(3-)group and Eu^(3+)/Sm^(3+)ions is observed in the temperature-dependent emission spectra of Na_(2)LuMg_(2)V_(3)O_(12):Eu^(3+)and Na_(2)LuMg_(2)V_(3)O_(12):Sm^(3+).By taking advantage of the luminescence intensity ratio(LIR)between VO_(4)^(3-)group and Eu^(3+)/Sm^(3+)ions in Na_(2)LuMg_(2)V_(3)O_(12):0.01Eu^(3+)and Na_(2)LuMg_(2)V_(3)O_(12):0.07Sm^(3+),two new types of optical thermometry mediums were designed and their basic temperature sensing parameters were calculated.展开更多
We demonstrate a case study of Ce-doped yttrium aluminum garnet(YAG)phosphor to illustrate a novel plasma route for the synthesis of multicomponent materials with addressing morphology and structural control.The prese...We demonstrate a case study of Ce-doped yttrium aluminum garnet(YAG)phosphor to illustrate a novel plasma route for the synthesis of multicomponent materials with addressing morphology and structural control.The presented strategy was started directly from liquid precursors without any precipitating agents,and an innovative growth mechanism was proposed to explain the formation of monodispersed spherical particles with an adjusted size distribution.Homogeneous elemental distribution close to that of liquid precursors was also achieved due to the thermal nonequilibrium effect in plasma.Benefiting from the structural feature of the obtained product,a low transformation temperature of 1100℃for YAG phase was obtained and final products exhibit the highest photoluminescence intensity with rather low Ce doping of 0.5 wt.%,together with excellent thermal stability of 92%preservation of initial emission at 473 K.This work well illustrates the advance of plasma strategy in formation of multicomponent com-pounds with excellent performances,and its potential for large-scale production due to the transient and in-flight synthesis process.展开更多
Er^(3+)-doped BaLaGaO_(4)green phosphors was synthesized through a high-temperature solid-state reaction technique.The phase structure and morphology test results of the phosphor indicate that the BaLaGaO_(4)material ...Er^(3+)-doped BaLaGaO_(4)green phosphors was synthesized through a high-temperature solid-state reaction technique.The phase structure and morphology test results of the phosphor indicate that the BaLaGaO_(4)material was successfully synthesized and Er^(3+)ions were successfully doped into the main lattice.This doping does change the basic structure of the crystal.BaLaGaO_(4):Er^(3+)phosphor exhibits bright green emission centered at 545 nm when excited by 381 nm ultraviolet light or 980 nm near-infrared light.The optimal doping concentration is found to be x=0.04.To quantify the temperature sensitivity of the phosphor,the fluorescence intensity ratio method was used.Within the temperature range of 298-473 K,the maximum relative sensitivities are 1.35%/K(298 K,381 nm)and 1.45%/K(298 K,980 nm),respectively.The maximum absolute sensitivities are 0.67%/K(473 K,381 nm)and 0.69%/K(473 K,980 nm),respectively.Finally,white light-emitting diodes(WLEDs)with a high colour index of Ra=82and a relatively low correlated colour temperature of CCT=5064 K are obtained by integrating the synthesized BaLaGaO_(4):0.04Er^(3+)green phosphor into warm WLEDs devices.These results suggest that Er^(3+)-activated BaLaGaO_(4)multifunctional phosphors hold considerable promise in the areas of optical temperature sensing and WLEDs phosphor conversion.展开更多
A blue-red dual-emitting phosphor,Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+),Mn^(2+)was developed in this study.Eu^(2+)acts as a sensitizer ion in Na_(3)KMg_(7)(PO_(4))_(6):Mn^(2+),which significantly improves the undesirable ...A blue-red dual-emitting phosphor,Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+),Mn^(2+)was developed in this study.Eu^(2+)acts as a sensitizer ion in Na_(3)KMg_(7)(PO_(4))_(6):Mn^(2+),which significantly improves the undesirable luminous efficiency of Mn^(2+).The energy transfer between Eu^(2+)and Mn^(2+)significantly boosts both internal quantum efficiency(IQE)and external quantum efficiency(EQE)of the phosphor,achieving values of 72.5%and 42.6%,respectively.Additionally,the phosphor demonstrates exceptional thermal stability,at150℃.maintaining 71.49%of its initial emission intensity.The emission spectrum of the phosphor closely matches the chlorophyll's absorption spectra,with similarities of 75.06%and 94.52%,respectively.This was further confirmed through a fabricated LED with a n-UV chip(395 nm).To further assess the potential for agritech applications,a light-conversion film incorporating the developed phosphor in PDMS glue was prepared.An outdoor cultivation trial with Chlorella showed that the algae's growth rate improves by 27.3%relative to a control group.These results reveal the significant potential of the Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+),Mn^(2+)phosphor for enhancing plant growth in practical applications.展开更多
基金Project (51074016) support by the National Natural Science Foundation of China
文摘High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better beneficiation index were gotten by direct reduction roasting with dephosphorization agent followed by two stages of grinding and magnetic separation. P content decreases from 0.82% in the raw ore to 0.06% in the magnetic concentrate, and the total iron grade increases from 43.65% to 90.23%, the recovery of iron can reach 87%. Mechanisms of phosphorus removal in the beneficiation of high phosphorous oolitic hematite ore by direct reduction roasting with dephosphorization agent were studied using XRD, SEM and EPMA. The results showed that about 20% of the apatite in the raw ore transferred into phosphorus and volatilized with the gas in the process of reduction roasting, while the rest 80% apatite was not involved in the reaction of generation of phosphorus, and remained as apatite in the roasted products, which was removed to tailings by grinding and magnetic separation. A small amount of phosphorus existed in the magnetic concentrate as apatite. The oolitic texture of raw ore was partly changed during roasting, resulting in the formation of nepheline in the reaction between the dephosphorization agent, SiO2 and Al2O3 in the raw ore, which greatly improved the liberation degree of minerals in the roasted products, and it was beneficial to the subsequent grinding and magnetic separation.
基金National Key Research and Development Program of China(2021YFB3500501)。
文摘Commercial phosphor-converted white LEDs(pc-WLEDs)face two inherent limitations,namely blue light hazard and low color rendering index,due to the use of blue LEDs as excitation source.To address these challenges,violet LEDs are proposed as an alternative solution.Currently,phosphors that can be efficiently excited by violet light(with wavelengths from 400 to 420 nm)remain under development still.In this study,we utilize large language models to construct a comprehensive database of Eu^(2+)and Ce^(3+)doped phosphors for discovering novel violet-excited phosphors.A total of 822 phosphor data entries,including elemental compositions,crystal structures and excitation/emission wavelengths,have been extracted and validated from 9551 research papers.Compared with Ce^(3+)doped phosphors,the Eu^(2+)are in general more suited for violet-excited phosphors,as well as red-emitting phosphors.In particular,Eu^(2+)doped nitrides and sulfides are worth of exploration for violet-excited phosphors.This database is expected to be useful in the future development of phosphors for pc-WLEDs based on artificial intelligence methods.The datasets in this article are listed in Science Data Bank at http://doi.org/10.57760/sciencedb.34314.
基金Project supported by the National Natural Science Foundation of China(12374181)Fundamental Research Funds for Public Universities in Liaoning(LJ212410140035,LJ212410140037,LJ212410140048)+2 种基金Shenyang Science and Technology Bureau(22-315-6-06)General Project of the Department of Education of Liaoning Province(LJKZ0084)Liaoning Province Science and Technology Plan Joint Program(Natural Science Foundation General Project,2024-MSLH-188)。
文摘Long-afterglow photocatalytic technology offers promising potential fo r all-weather pollutant treatment,yet its efficiency is often constrained by competition between afterglow emission and photocatalytic reactions.To address this,we developed a Pr^(3+)-doped Ca_(2)Al_(2)SiO_(7)(CASO)photocatalyst enriched with oxygen vacancies(V_(O)).The introduction of oxygen vacancies significantly increases trap concentration,enhancing both the intensity and du ration of the afterglow emission.A persulfate-assisted photo-Fenton system was designed based on V_(O)-CASO:Pr^(3+)enabling the self-activated degradation of tetracycline hydrochloride(TC)under ultraviolet afterglow.The photo-Fenton reaction consumes excess holes accumulated during the afterglow process,improving carrier utilization efficiency and mitigating rapid recombination.Additionally,persulfate addition can enrich reactive species and facilitate the Fe^(2+)/Fe^(3+)cycle.Benefiting from these synergistic effects,V_(O)-CASO:Pr^(3+)has achieved 75%TC degradation within1 h,significantly outperforming traditional systems.This study provides a new strategy for enhancing long-afterglow photocatalytic performance,paving the way for sustainable pollutant degradation technologies.
基金Project supported by the National Key Research and Development Program(2022YFE0108800)。
文摘Eu^(2+)-doped phosphors show broadband absorption,tunable emission and high quantum efficiency due to the parity-allowed 5d→4f transitions,allowing them to be used in solid-state lighting.To expand their applications in other fields such as detection and sensing technologies,the Eu^(2+)emission needs to be tuned into the near-infrared region,but it is a big challenge to obtain Eu^(2+)near-infrared region emitters due to the absence of host compounds with extremely large crystal-field splitting.In this work,we chose M_(4)Li(BN_(2))_(3)(M=Ca,Sr,Ba)as a host and realize the near-infrared region emission of Eu^(2+)in it.Among these phosphors,Ba4Li(BN_(2))_(3):Eu^(2+)exhibits the longest emission of 880 nm and the largest full-width at half maximum of 276 nm under 450 nm excitation,while Ca_(4)Li(BN_(2))_(3):Eu^(2+)and Sr_(4)Li(BN_(2))_(3):Eu^(2+)emit at740 and 680 nm,respectively.We observe an interesting phenomenon that the energy shift of emission is linearly related to the radius difference between the alkaline earth cation and the activator Eu^(2+)in this system.
基金Project supported by the National Natural Science Foundation of China(52403403)Guizhou Provincial Basic Research Program(Natural Science)(Qian ke he ji chu-ZK 20242024 YiBan 095)。
文摘Although significant progress has been made in the development of red phosphors,the development of efficient and thermally stable red phosphors remains a challenge.In this paper,(Sr_(3-y)Cay)Ca_(1-x)Nb_(2)O_(9):xSm^(3+)phosphors with 648 nm red emission,which belongs to the ^(4)G_(5/2)→^(6)H_(9/2) leap of Sm^(3+)and is close to the absorption wavelengths of plant chloro phylls and photochromes PR,were prepared by the high-temperature solid-phase method.The lattice mismatch between Sm^(3+)and Ca^(2+)is solved by cation substitution,which increases the atomic disorder and lattice distortion,and the lattice distortion also causes the forbidden leap to be disrupted,thus improving the luminescence efficiency.Meanwhile,the substitution of small-radius cations leads to the enhancement of the structural rigidity of the material.The test results show that after the introduction of Ca^(2+),the luminous intensity of the phosphor is increased by 5.15 times,the quantum yield is increased from 22.89%to 48.31%,and the I_(423 K)/I_(298 K) value is increased from 70.7%to 73.4%,and the fluorescence lifetime is also improved accordingly.White light-emitting diodes(WLEDs)and fuchsia light-emitting diodes(LEDs)were successfully prepared using the experimentally prepared phosphors,demonstrating their great potential in the fields of optical thermometers,WLEDs and plant growth.
文摘Five samples of LiMgPO_(4):Gd were prepared via five different production processes using a solid-state reaction method.The effects of the preparation process on optically stimulated luminescence(OSL)and thermoluminescence(TL)were investigated.Considering its high sensitivity,low fading,and minimum detectable dose(MDD),the LiMgPO_(4):Gd phosphor heated to 900℃for 15 h is concluded to be optimal.The effects of annealing on the OSL sensitivity,relative residual OSL signals measured after 24 h of irradiation,and MDD of LiMgPO_(4):Gd phosphors heated to 900℃for 15 h were also investigated.Considering its high sensitivity,low fading,and MDD,annealing at 350℃for 1 h is concluded to be optimal.The OSL signal of LiMgPO_(4):Gd was derived from the principal TL glow peak.For a maximum integration time of 5 s,the OSL signal was stable,with no fading 30 days after irradiation.LiMgPO_(4):Gd eliminated approximately 2.2%of the OSL signal at each readout for a readout time of 0.1 s,which is sufficient for fast and multiple OSL readout.The sensitivity of LiMgPO_(4):Gd phosphor,annealed for 1 h at 350℃with a reading time of 0.1 s,was found to be approximately 98%of that observed forα-Al_(2)O_(3):C(TLD-500k),which should be sufficient for low-dose measurements in personal,workplace,and environmental dosimetry.
基金supported by the National Natural Science Foundation(NSF)of China(62475265,22031009,22075282,12404064)the National Key Research and Development Program of China(2021YFB3601501)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1170000)NSF of Fujian Province(2023J01212,2024J08106).
文摘Heat-induced emission peak shift(HIEPS),encompassing both redshift and blueshift,remains mechanistically unresolved in phosphor materials.Using state-of-the-art first-principles calculations of M_(2)SiO_(4):Eu^(2+)(M=Sr,Ba,Ca),we reveal that conventional thermal expansion theory cannot adequately explain these phenomena.Instead,our frozen phonon analysis identifies local electron-phonon coupling as the dominant mechanism,where anisotropic thermal vibrations selectively distort the asymmetric Eu-5d potential well that arises from the dopant’s coordination environment.This distortion manifests through the temperature-sensitiveΔ_(f−d) parameter governing the 5d→4f transition energy,directly controlling spectral shifts.Our findings establish a universal framework for HIEPS in rare-earth phosphors and enable a Δ_(f−d)-guided strategy for designing thermally stable phosphors.
基金Funded by the Sichuan Province Science and Technology Support Program(No.2025YFNZH0022)the Chengdu Municipal Science and Technology Program(No.2025-YF11-00003-HZ)。
文摘Curing temperature significantly affects the pozzolanic reaction kinetics of phosphorous slag(PS),thereby governing the early-age(7 d)hydration behavior of PS composite binders at 20,30,and 60℃.The Krstulovic-Dabic kinetic model was applied to identify three characteristic processes:nucleation and growth(NG),phase boundary interaction(I),and diffusion(D).Control mixtures containing inert quartz powder with comparable particle size distributions were prepared for comparison.Pore characteristics of hardened PS pastes at different temperatures were analyzed via mercury intrusion porosimetry,while hydration products were characterized using X-ray diffraction(XRD)and thermogravimetric analysis(TG-DTG).The experimental results indicate that the retarding effect of PS on early cement hydration outweighs its accelerating effect,attributed to the combined influence of nucleation and dilution,with retardation decreasing as temperature increases.PS exhibits early reactivity and continuously consumes calcium hydroxide through the pozzolanic reaction,as evidenced by stable phase assemblages accompanied by reduced CH content in XRD and TG-DTG analyses.At 20℃,increasing PS content maintains the NG→I→D mechanism but slows reaction rates across all stages.Elevated temperatures significantly accelerate the NG process,shifting the dominant mechanism from NG toward D.Simultaneously,enhanced PS reactivity contributes to a refined pore structure and improved compressive strength.
基金financially supported by the Natural Science Foundation of China(Nos.22208214,22005190,and 21938005)the Science&Technology Commission of Shanghai Municipality(Nos.20QB1405700,and 19DZ1205500)Zhejiang Key Research and Development Program(No.2020C01128)
文摘Sodium-ion batteries(SIBs) are promising electrochemical energy storage systems as lithium-ion batteries by virtue of their similar chemical properties and natural abundance and availability.However,the ionic radius of Na^(+)is larger than that of Li^(+),leading to challenges in its insertion/extraction at anode side.As a class of anode materials,phosphorus allotropes(PAs,red,and black) and metal phosphides(MPs) have shown great prospects because of high theoretical gravimetric/volumetric capacity,high carrier mobility,and suitable redox potential.In this review,recent developments in the studies of PAs and MPs with particular emphasis on understanding sodium storage mechanisms,developing novel synthesis strategies,and performance validations have been manifested valuable solutions to address these challenges.We begin with the introduction and classification of the macroscopic sodiation mechanisms of PAs and MPs,and the various fabrication strategies of PAs and MPs are comprehensively summarized in second section.The third section thoroughly reviews the progresses on PAs and MPs-based advanced materials for their application in SIBs.Finally,we also discuss the significant challenges and outline a roadmap for future research directions.
基金support by the National Natural Science Foundation of Inner Mongolia (2022SHZR1885)Natural Science Foundation of Hebei province (E2022402101,E2022402105)。
文摘To completely recover valuable elements and reduce the amount of waste,the impact of phosphoric acid on the decomposition of rare earth,fluorine and phosphorus during cyclic leaching was studied based on the characteristics of low-tempe rature sulfuric acid deco mposition.When a single monazite was leached using 75 wt% H_(2)SO_(4) solution with phosphoric acid,the size and number of monazite particles in the washing slag gradually decrease with the increase in phosphoric acid content in the leaching solution.The monazite phase can hardly be found in the slag when the phosphoric acid content reaches 70 g/L,which indicates that phosphoric acid is favorable for monazite decomposition.The mixed rare earth concentrate was leached by 75 wt% H_(2)SO_(4) containing 70 g/L phosphoric acid,the mineral compositions of the washing slag are only gypsum and unwashed rare earth sulfuric acid.After cyclic leaching of75 wt% H_(2)SO_(4),the mineral compositions of the primary leaching washing slag are mainly undecomposed monazite,rare earth sulfate and calcium sulfate.However,monazite is not found in the mineral phase of the second and third leaching washing slag.The leaching rates of rare earth and phosphorus gradually increase with the increase in cyclic leaching times.In addition,the phosphoric acid content in the leaching solution increases with the increase in the number of cyclic leaching time.However,the rising trend decreases when the phosphoric acid content reaches 50 g/L by adsorption and crystallization of phosphoric acid.A small amount of water can be used to clean the leaching residue before washing to recover the more soluble phosphorus acid according to the difference of dissolution between phosphoric acid and rare earth sulfuric acid.
基金supported by the National Natural Science Foundation of China(Grant Nos.51991351 and51903132)the Young Elite Scientist Sponsorship Program by CAST(No.2022QNRC001).
文摘Different reactive flame retardants have been extensively developed for vinyl ester resins(VERs),but very few of them can yield a flame-retardant resin that meets defined standards(e.g.UL-94 V-0 rating).In this work,phosphorous-containing 1-vinylimidazole salts(called VIDHP and VIDPP)were synthesized through the facile neutralization of the acid and 1-vinylimidazole.VIDHP and VIDPP were then applied as flame-retardant crosslinking agents of VERs,by which phosphorus-containing groups could be incorporated into the resin chain via ionic bonds.VIDHP/VER and VIDPP/VER showed a high curing activity and can be well cured in moderate temperatures.With 20 wt.%additions of VIDHP and VIDPP,VIDHP20/VER,and VIDPP20/VER presented a limiting oxygen index value of 29.7%and 28.4%,respectively,with the latter achieving a UL 94 V0 rating.In the cone calorimetric test,compared to the unmodified VERs,VIDPP20/VER exhibited large reductions in the peak heat release rate,total heat release rate,and total smoke release rate while VIDHP20/VER demonstrated comparatively inferior performance in terms of the heat release.VIDHP20/VER and VIDPP20/VER showed good thermal stability and presented a little lower glass transition temperature than the control sample.VIDPP with a low phosphorus oxidation state(+1)demonstrated high flame-retardant activities in the gaseous phase,whereas VIDHP with a high phosphorus oxidation state(+5)primarily exhibited efficacy in the condensed phase.
基金supported by grants from the National Natural Science Foundation of China(NSFC Nos.51972347 and 21771195).
文摘Inorganic lead-free double perovskites have the advantages of low toxicity,broadband emission,and good stability,which make them promising luminescent materials for lighting applications.However,due to the limited regulation of their self-trapped exciton emission,it is still greatly challenging to achieve white light emitting from a single double perovskite host.Herein,efficient and tunable white light is realized in Cs_(2)NalnCl_(6)∶Sb^(3+),Tb^(3+),Sm^(3+)double perovskite by controlling the ratios of the doped three ions with blue,green,and red emissions,respectively.The steady-state and transient fluorescence spectra of singly-and doubly-doped double perovskites reveal the existence of multiple energy transfer channels in the triply-doped phosphors,including from Sb^(3+)to Tb^(3+),Sb^(3+)to Sm^(3+),and Tb^(3+)to Sm^(3+).Benefiting from these channels,the color coordinates of the triply-doped phosphors can cross the whole white light area of the CIE chromaticity diagram by adjusting the ratios of the three dopants,and the maximum internal quantum yield of the white light phosphors is 66.61%.The white emission phosphors show the characteristic of being independent of excitation wavelength within 310-360 nm.Furthermore,the emission intensity at 430 K of the white light phosphor Cs_(2)NalnCl_(6)∶0.01Sb^(3+),0.65Tb^(3+),0.20Sm^(3+)remains 50% of that at room temperature.A WLED device fabricated with the phosphor and a 365 nm LED chip exhibits a high color rendering index of 90.9,correlated color temperature of 5469 K,and CIE coordinates of(0.333 and 0.328).The results indicate that the as-prepared double perovskite materials are promising candidates in the solid-state lighting field.
基金the support of the National Key Research and Development Program of China(No.2018YFE0306103)the National Natural Science Foundation of China(No.52071050)the Science and Technology Innovation Project of Ningbo,China(No.2021Z032).
文摘To optimize the comprehensive properties of Ni−Si precipitation strengthened phosphor bronze,the impact of the Ni/Si mass ratio and heat treatment process on a Cu−8Sn−0.1P−1Ni−xSi alloy was explored.High resolution field emission scanning electron microscopy and transmission electron microscopy were used for microstructural characterization.The results indicate that the properties are influenced by the Ni/Si mass ratio,attributed to the formation of various second phases.Simultaneously,by influencing the diffusion rate,the microstructures and properties are influenced by the solid solution treatment.The strength is enhanced by precipitated nanoscale particles during the aging process by influencing the motion of dislocations.Ultimately,excellent comprehensive properties,including ultimate tensile strength,yield strength,and elongation of 866 MPa,772 MPa,and 8.7%,respectively,are obtained in the Cu−8Sn−0.1P−1Ni−0.227Si alloy.
文摘The catalytic enantioselective electrophilic amination reaction has emerged as a highly efficient method for synthesizing diverse nitrogen-containing chiral molecules,with the development of various asymmetric catalysis systems.Chiral phosphoric acids(CPA)have been widely acknowledged as versatile chiral organocatalysts since it was first discovered in 2004,finding application in catalyzing diverse asymmetric reactions.A comprehensive overview of recent advances in CPA-catalyzed asymmetric electrophilic amination reactions using different N-electrophilic reagents,including azo reagents,aryldiazonium salts,and imine derivatives,is presented.Furthermore,insights into future developments in this field are offered.
基金Project supported by the National Natural Science Foundation of China(12074373,12474415,U22A20139)the Major Science and Technology Project of Anhui Province(2021e03020007)+1 种基金the Developing Project of Science and Technology of Jilin Province(the Natural Science Foundation,20210101473JC)the Key Laboratory of Advanced Structural Materials(ASM-202205)。
文摘Broadband near-infrared(NIR)phosphor-conve rted light-emitting diode(pc-LED)is a new generation of light source for spectroscopy applications.Current studies generate a broad continuous NIR spectrum to promise the detection of a wide range of substances.This paper reports a discontinuous NIR spectral distribution peaking at 760 and 1400 nm,respectively,by co-doping Cr^(3+)and Ni^(2+)ions into CaLu_(2)Mg_(2)Si_(3)O_(12)garnet.The benefit of such a discontinuous spectrum is its ability to prevent energy waste in specific applications,such as moisture(freshness)and hemoglobin detection,where only spectral bands near 750 and 1500 nm are required.The discontinuous spectrum is attributed to the ene rgy transfer from Cr^(3+)to Ni^(2+)ions.The NIR pc-LED fabricated by the new phosphor shows photoelectric efficiency of 9.12%@10 mA and NIR output power of 11.44 mW@100 mA.The NIR pc-LED also performs well when measuring alcohol solution where only a discontinuous spectrum is needed.These results highlight the potential of NIR phosphors with a discontinuous spectrum across a broad 700-1600 nm range.
基金financially supported by the Caiyun Postdoctoral Innovation Project(No.C615300504089)Yunnan Fundamental Research Project(No.202401AS070128)National Natural Science Foundation of China(No.22165031).
文摘Bifunctional applications in solid state lighting and optical thermometry are attractive in the optical field.Despite Eu^(3+)doped phosphors are widely used in white-LEDs,phosphors with high temperature sensitivity remain rare.Herein,NaLnTe_(2)O_(7):Eu^(3+)(Ln=Y and Gd)phosphors were synthesized using a rapid microwave-assisted solidstate(MASS)method to fulfill these applications.Under 395 nm excitation,NaLnTe_(2)O_(7):Eu^(3+)exhibit the characteristic ^(5)D_(0)→^(7)F_(J)(J=1–4)transitions of Eu^(3+).Substituting Gd^(3+) for Y^(3+) enhances the luminescence by approximately 2.42 times.Structural analyses reveal that the improved luminescent properties are attributed to the more distorted and appropriate coordination environment in NaGdTe_(2)O_(7):Eu^(3+).Finally,white-LEDs using NaGdTe_(2)O_(7):Eu^(3+)as the red-component produce white light with high Ra of 89.Furthermore,the distinct thermal responses of the ^(5)D_(0)→^(7)F_(J) transitions enable NaLnTe_(2)O_(7):Eu^(3+)to function as temperature sensors via fluorescence intensity ratio(FIR)strategy.NaYTe_(2)O_(7):Eu^(3+)possesses the maximum relative/absolute sensitivity of 1.45%/15.93%K^(-1),whereas NaGdTe_(2)O_(7):Eu^(3+)achieves the maximum relative/absolute sensitivity of 1.53%/30.24% K^(-1).This work highlights the significance of cationic substitution in enhancing luminescent properties for multifunctional applications.
基金Project supported by Natural Science Foundation of Shandong Province(ZR2020KF017,ZR2020QE053,ZR2023QB261)the Natural Science Foundation of Anhui Province(2108085MB53)。
文摘To develop efficient luminescence and optical thermometry materials for color display and non-contact temperature measurement,novel RE^(3+)(RE=Eu,Sm)doped self-activated Na_(2)LuMg_(2)V_(3)O_(12)phosphors were prepared by a typical solid-state reaction method.Their crystal structure,morphology,multi-color luminescence and temperature sensing properties were elaborately investigated.Under UV light excitation,an intense and broad green-yellow emission band from VO_(4)^(3-)group is observed in the Na_(2)LuMg_(2)V_(3)O_(12)matrix,indicating its potential application in solid state lighting.After the incorpo ration of Eu^(3+)and Sm^(3+)ions,efficient energy transfer(ET)from VO_(4)^(3-)group to Eu^(3+)/Sm^(3+)ions occurs and the emission color of the samples can be readily tuned among different color ranges.Besides,based on the change of luminescence intensity and lifetimes of VO_(4)^(3-)group in Na_(2)LuMg_(2)V_(3)O_(12):Eu^(3+)and Na_(2)LuMg_(2)V_(3)O_(12):Sm^(3+),the ET efficiency was analyzed and the mechanism is illustrated.Finally,large discrepancy between the thermal stability of VO_(4)^(3-)group and Eu^(3+)/Sm^(3+)ions is observed in the temperature-dependent emission spectra of Na_(2)LuMg_(2)V_(3)O_(12):Eu^(3+)and Na_(2)LuMg_(2)V_(3)O_(12):Sm^(3+).By taking advantage of the luminescence intensity ratio(LIR)between VO_(4)^(3-)group and Eu^(3+)/Sm^(3+)ions in Na_(2)LuMg_(2)V_(3)O_(12):0.01Eu^(3+)and Na_(2)LuMg_(2)V_(3)O_(12):0.07Sm^(3+),two new types of optical thermometry mediums were designed and their basic temperature sensing parameters were calculated.
基金supported by the National Natu-ral Science Foundation of China(No.52174342)the Beijing Nat-ural Science Foundation(No.2232044)the Beijing Munic-ipal Education Commission Research Plan General Project(No.KM202410005009).
文摘We demonstrate a case study of Ce-doped yttrium aluminum garnet(YAG)phosphor to illustrate a novel plasma route for the synthesis of multicomponent materials with addressing morphology and structural control.The presented strategy was started directly from liquid precursors without any precipitating agents,and an innovative growth mechanism was proposed to explain the formation of monodispersed spherical particles with an adjusted size distribution.Homogeneous elemental distribution close to that of liquid precursors was also achieved due to the thermal nonequilibrium effect in plasma.Benefiting from the structural feature of the obtained product,a low transformation temperature of 1100℃for YAG phase was obtained and final products exhibit the highest photoluminescence intensity with rather low Ce doping of 0.5 wt.%,together with excellent thermal stability of 92%preservation of initial emission at 473 K.This work well illustrates the advance of plasma strategy in formation of multicomponent com-pounds with excellent performances,and its potential for large-scale production due to the transient and in-flight synthesis process.
基金supported by the National Natural Science Foundation of China(52403403)Guizhou Provincial Basic Research Program(Natural Science)(Qian ke he ji chu-ZK2024 YiBan 095)。
文摘Er^(3+)-doped BaLaGaO_(4)green phosphors was synthesized through a high-temperature solid-state reaction technique.The phase structure and morphology test results of the phosphor indicate that the BaLaGaO_(4)material was successfully synthesized and Er^(3+)ions were successfully doped into the main lattice.This doping does change the basic structure of the crystal.BaLaGaO_(4):Er^(3+)phosphor exhibits bright green emission centered at 545 nm when excited by 381 nm ultraviolet light or 980 nm near-infrared light.The optimal doping concentration is found to be x=0.04.To quantify the temperature sensitivity of the phosphor,the fluorescence intensity ratio method was used.Within the temperature range of 298-473 K,the maximum relative sensitivities are 1.35%/K(298 K,381 nm)and 1.45%/K(298 K,980 nm),respectively.The maximum absolute sensitivities are 0.67%/K(473 K,381 nm)and 0.69%/K(473 K,980 nm),respectively.Finally,white light-emitting diodes(WLEDs)with a high colour index of Ra=82and a relatively low correlated colour temperature of CCT=5064 K are obtained by integrating the synthesized BaLaGaO_(4):0.04Er^(3+)green phosphor into warm WLEDs devices.These results suggest that Er^(3+)-activated BaLaGaO_(4)multifunctional phosphors hold considerable promise in the areas of optical temperature sensing and WLEDs phosphor conversion.
基金supported by the Department of Industry and Information Technology of Gansu Province(2024 Provincial Key Talent Program)the National Natural Science Foundation of China(U22A20136)。
文摘A blue-red dual-emitting phosphor,Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+),Mn^(2+)was developed in this study.Eu^(2+)acts as a sensitizer ion in Na_(3)KMg_(7)(PO_(4))_(6):Mn^(2+),which significantly improves the undesirable luminous efficiency of Mn^(2+).The energy transfer between Eu^(2+)and Mn^(2+)significantly boosts both internal quantum efficiency(IQE)and external quantum efficiency(EQE)of the phosphor,achieving values of 72.5%and 42.6%,respectively.Additionally,the phosphor demonstrates exceptional thermal stability,at150℃.maintaining 71.49%of its initial emission intensity.The emission spectrum of the phosphor closely matches the chlorophyll's absorption spectra,with similarities of 75.06%and 94.52%,respectively.This was further confirmed through a fabricated LED with a n-UV chip(395 nm).To further assess the potential for agritech applications,a light-conversion film incorporating the developed phosphor in PDMS glue was prepared.An outdoor cultivation trial with Chlorella showed that the algae's growth rate improves by 27.3%relative to a control group.These results reveal the significant potential of the Na_(3)KMg_(7)(PO_(4))_(6):Eu^(2+),Mn^(2+)phosphor for enhancing plant growth in practical applications.
