低热固相反应法合成掺Eu~（3＋）的双磷酸盐KZnLa（PO_4）_2及其光致发光性能研究

在表面活性剂PEG-400的存在下,于室温下研磨ZnSO4.7H2O,La（NO3）2和K3PO4.3H2O的混合物,使其进行固态反应。研磨结束后,将反应混合物在60℃下保温4 h。用去离子水洗去混合物中的可溶性无机盐,在100℃下烘干,即得纳米晶KZnLa（PO4）2的前驱体。煅烧前驱体得到纳米晶KZnLa（PO4）2。前驱体和它的煅烧产物通过热重和微分热分析,傅立叶变换红外光谱和X-射线粉末衍射表征。结果表明,前驱体仅是结晶度低的化合物;前驱体在高于700℃下煅烧2 h,得到具有高结晶度的纳米晶KZnLa（PO4）2。以相同方法合成了KZnLa0.94Eu0.06（PO4）2,在900℃下煅烧2 h,得到的KZnLa0.94Eu0.06（PO4）2在紫外线照射下是一种发射红光的荧光粉。     

白光LED用蓝色荧光粉Sr10（PO4）6Cl2:Eu2+合成及其光谱特性

本文采用传统的高温固相法合成白光LED用Sr10(PO4)6Cl2:Eu2+蓝色荧光粉,利用X-射线粉末衍射和荧光光谱进行表征。实验结果表明,在紫外近紫外区(200～400 nm)激发下荧光粉发射光谱主峰位于447 nm。当灼烧温度为1000℃,Eu2+掺杂浓度为0.12,SrCl2.6H2O添加量过量20%,发光强度最高。与商业近紫外LED芯片发射相匹配,是一种优秀的近紫外白光LED用的蓝色荧光粉。     

GdF3∶Eu3+和NaGdF4∶Eu3+发光粉的可控合成与发光性质

采用聚乙烯吡咯烷酮(PVP)辅助水热法合成了GdF3∶Eu3+和NaGdF4∶Eu3+发光粉。利用X射线衍射(XRD)、扫描电子显微镜和荧光光谱对样品的结构、形貌和发光性能进行了研究。XRD分析表明:GdF3晶相到NaGdF4晶相的转换可以通过改变初始溶液pH值、PVP加入量和NaF与稀土离子(Gd3+和Eu3+)摩尔配比等合成条件实现。NaGdF4∶Eu3+发光粉的形貌受合成条件的影响。荧光光谱研究表明:GdF3∶Eu3+发光粉主发射峰位于593nm处,来自于Eu3+的5 D0→7 F1磁偶极跃迁;NaGdF4∶Eu3+发光粉主发射峰位于616nm,来自于Eu3+的5 D0→7 F2电偶极跃迁。2个样品中Gd3+与Eu3+离子之间存在较好的能量传递,而NaGdF4晶格更有利于2种离子的能量传递。     

红色荧光粉CaWO4:Eu3+,Gd3+的合成及其发光性能的研究

利用高温固相法合成了CaWO4:Eu3+,Gd3+红色荧光粉,通过X射线衍射、X射线光电子能谱和荧光光谱等对该荧光粉进行了表征。结果表明,CaWO4:Eu3+,Gd3+的荧光强度明显高于CaWO4:Eu3+,钆离子的最佳掺杂量为0.04。同时说明了钆离子引入到CaWO4:Eu3+中对其发光性能影响的机理以及不同浓度的钆对发光强度的影响。     

白光SrMoO4:Eu3+,K+@g-C3N4荧光粉的合成及其性能研究

为了获得单一基质白光荧光粉，以三聚氰胺为原料，采用热分解法制备g-C₃N₄蓝色荧光粉，采用高温固相法制备了Sr_0.92Mo O₄:0.08Eu³⁺(SMO:E)和Sr_0.82Mo O₄:0.08Eu³⁺,0.10K⁺(SMO:EK)红色荧光粉，通过沉淀吸附反应制备了Sr_0.82Mo O₄:0.08Eu³⁺,0.10K⁺@0.013g-C₃N₄(SMO:EK-CN)复合荧光粉。利用X射线粉末衍射、红外光谱、荧光光谱、热猝灭分析对荧光粉进行表征，分别探讨了Eu³⁺单掺杂和Eu³⁺、K⁺共掺杂以及Eu³⁺、K⁺、g-C₃N₄     

掺杂RE3+对CaAl2O4:Eu2+,Nd3+发光性能的影响

以燃烧法合成了CaAl2O4∶Eu2+,Nd3+,RE3+紫色长余辉发光材料。实验结果表明,掺杂辅助激活剂Pr3+和Ce3+对CaAl2O4∶Eu2+,Nd3+磷光体发光性能有明显影响。掺杂Pr3+的CaAl2O4∶Eu2+,Nd3+样品的发射峰蓝移;掺杂Ce3+的CaAl2O4∶Eu2+,Nd3+样品的发射峰红移。Pr3+或Ce3+掺杂,可以提高CaAl2O4∶Eu2+,Nd3+磷光体的初始亮度,Pr3+或Ce3+在其中起到增加陷阱密度,提高发光亮度的作用。     

Yb3+和Er3+共掺杂的NaY（WO4）2纳米晶的制备与发光性能

采用水热法制备出NaY(WO4):Yb3+,Er3+纳米发光粉。通过X射线衍射、扫描电子显微镜表征了制备的发光粉样品;研究了不同Yb/Er摩尔比对发光强度的影响。结果表明:Yb3+和Er3+共掺杂的NaY(WO4)2属于四方晶系,其粒径在30 nm左右,且分散均匀。当Yb/Er摩尔比为4:1时,NaY(WO4):Yb3+,Er3+发光粉样品的发射峰强度达到了最大值。用980nm激光对其进行激发,在室温下观察到了410、524、553和656nm的发射峰,分别对应于2H9/2→4I15/2,2H11/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2的跃迁。根据激发功率与发光强度的关系得出410、524、553和656 nm发射峰均为双光子过程。     

Dy3+掺杂的LiY（MoO4）2发光材料的制备与光谱特性

采用高温固相法在800℃制备了LiY(MoO4)2:Dy3+荧光粉。研究了Dy3+掺杂量、合成温度以及Li+的过量加入对LiY(MoO4)2:Dy3+荧光粉发光强度的影响。结果表明:在紫外光(386nm)激发下,该荧光粉的发射光谱为1个峰值位于488nm和575nm的双峰谱线,其中位于575nm处的黄光发射最强;监测575 nm发射峰得到的激发光谱为主峰位于351、366、386 nm和426 nm的线状谱线。煅烧温度为800℃时合成的荧光粉样品的发光强度达到最大,加入过量的Li+会降低发光强度。随Dy3+掺杂量的增大,荧光粉的发光强度逐渐增强,当Dy3+掺杂量为6%时发射的谱线强度最大。荧光粉的色参数表明,该荧光粉是一种较好的用于白光LED的黄色发光材料。     

多级结构SrB2O4:Eu3+花状微球的制备及其性能的研究

以稀土元素Eu3+为激活剂,PVP为模板剂,采用微波液相加热法及后续热处理制备了多级结构SrB2O4:Eu3+花状微球发光材料。并采用XRD、SEM、TEM、PL等手段对样品进行表征。花状微球直径约为3μm,并且微球是由厚度约为50 nm的纳米片组装而成的。PL结果表明样品发射高强度的红光,强激发带位于393 nm。主要发射峰位于613 nm对应于Eu3+的5D0→7F2。所得样品有望应用于荧光灯、显示系统和光电设备上。     

梭状NaLa（MoO4）2的微波溶剂热合成及其发光性能

通过微波溶剂热法合成梭状 NaLa（MoO4）2粉体,研究了乙二醇与水的体积比、反应温度和反应物浓度等参数对产物形貌和尺寸的影响。利用X 射线衍射仪、扫描电子显微镜、双光束紫外–可见分光光度计和荧光光谱仪对产物的物相、结构、形貌和发光性能进行了研究。结果表明：在 150 ℃微波加热 6h,可合成出尺寸（长轴为 2μm、短轴为 0.3μm）均匀的四方相四棱梭状 NaLa（MoO4）2;Eu3＋掺杂后,NaLa（MoO4）2的四方相白钨矿结构没有改变;对 NaLa1–x（MoO4）2：xEu3＋的荧光光谱测试表明,其在 294nm 和 393nm 波长的紫外激发下,发射波长为 615nm 的红光;Eu3＋在 NaLa1–x（MoO4）2：xEu3＋（x = 0.025～0.200）中没有明显的浓度猝灭。     

磷酸钛铵的低热固相合成及其催化合成乙酸丁酯的研究

以Ti(SO4)2和(NH4)3PO4.3H2O为原料,在室温下研磨反应混合物,进行固相反应,然后在80℃下密封保温反应96 h,用水洗去混合物中的可溶性无机盐,80℃下烘干,即得纳米级磷酸钛铵产品。采用TG/DTA、IR、XRD和TEM对产品及其热解产品进行表征,采用均匀设计法考察了磷酸钛铵催化合成乙酸丁酯的性能。结果表明,80℃干燥3 h得到的是无定型磷酸钛铵产品,平均粒径约为40 nm,磷酸钛铵在合成乙酸丁酯中是一种极好的非均相催化剂。     

Optical properties of Eu3+/Pr3+ doped Zn4O(BO2)6 synthesized by solid-state reaction

Zn₄O(BO₂)₆ based on the [B₂₄O₄₈] sodalite-cage structure fixed by the inside [Zn₄O₁₃] clusters is expected to be a new class of solid-state lighting material with perfect thermal and mechanical stability. Herein, in the current work, we have respectively introduced non-equivalent rare-earth cations Eu³⁺ and Pr³⁺ into Zn₄O(BO₂)₆ host to design white and green emission materials by a novel solid-phase sintering method at lower temperatures. Zn₂B₆O₁₁ replacing B₂O₃ or H₃BO₃ as raw materials can effectively avoid the impure products caused by the uncontrollable volatilization of B₂O₃ or H₃BO_3. The newly designed light-emitting materials of Zn_4(1-x)O(BO₂)₆: xRe³⁺ (ReEu or Pr), including Zn₄O(BO₂)₆ host, have good absorption capacity in the ultraviolet region. Under ultraviolet irradiation, Zn₄O(BO₂)₆, Zn_4(1-x)O(BO₂)₆: xEu³⁺and Zn_4(1-x)O(BO₂)₆: xPr³⁺ emit the blue, white and green lights, respectively. In addition, all these materials can effectively degrade methylene blue, in which Zn_4(1-x)O(BO₂)₆: xPr³⁺ has the highest efficiency. The luminescence and degradation mechanisms of Zn₄O(BO₂)₆, Zn_4(1-x)O(BO₂)₆: xEu³⁺and Zn_4(1-x)O(BO₂)₆: xPr³⁺ have been adequately explained by their electronic structures based on the first principle calculations. The current study confirms that the doping of Eu³⁺/Pr³⁺ in Zn₄O(BO₂)₆ can broaden its applications as photoluminescent and photocatalytic materials.     

溶胶-凝胶法制备KZnLa（PO_4）_2：Ce,Tb及其荧光性能研究

采用溶胶-凝胶法合成KZnLa（PO4）2：Ce,Tb,并对其荧光性能进行研究,利用XRD、SEM对产物的物相结构、形貌进行研究,用荧光光度计对荧光粉的激发光谱和发射光谱测试,研究不同浓度的激活剂和敏化剂对荧光强度的影响。研究结果表明：制备的荧光粉粒径约200nm,为单斜向磷酸盐结构;改变La3＋,Ce3＋,Tb3＋浓度,将对相对荧光强度产生影响,且（KZn）0.3La0.45PO4∶0.2Tb,0.05Ce时,相对荧光强度最大。     

NaTi2(PO4)3纳米晶的室温固相合成及表征

以Ti(SO4)2和Na3PO4·12H2O为原料,在表面活性剂聚乙二醇(PEG)-400的存在下,进行固相反应,然后将混合物在60 ℃下保温4 h, 接着用水洗去混合物中的可溶性无机盐并于100 ℃下干燥,即得纳米晶NaTi2(PO4)3 的前驱体,将前驱体煅烧可得NaTi2(PO4)3纳米晶.前驱体和它的煅烧产物通过TG/DTA,IR,XRD和UV-vis表征.结果表明,500 ℃下煅烧2 h得到的产物为无定形结构,700 ℃下煅烧2 h得到具有高结晶度的斜方NaTi2-(PO4)3[空间群R-3c(167)],其平均一次粒径为47 nm.前驱体及煅烧产物均具有强的紫外吸收能力.     

Synthesis and photoluminescence properties of the high-brightness Eu3+-doped Sr3Y(PO4)3 red phosphors

A series of red-emitting phosphors Eu³⁺-doped Sr₃Y(PO₄)₃ have been successfully synthesized by conventional solid-state reaction, and its photoluminescence properties have been investigated. The excitation spectra reveal strong excitation bands at 392 nm, which match well with the popular emissions from near-UV light-emitting diode chips. The emission spectra of Sr₃Y(PO₄)₃:Eu³⁺ phosphors exhibit peaks associated with the ⁵D₀ → ⁷F_J (J = 0, 1, 2, 3, 4) transitions of Eu³⁺ and have dominating emission peak at 612 nm under 392 nm excitation. The integral intensity of the emission spectra of Sr₃Y_0.94(PO₄)₃:0.06Eu³⁺ phosphors excited at 392 nm is about 3.4 times higher than that of Y₂O₃:Eu³⁺ commercial red phosphor. The Commission Internationale de l’Eclairage chromaticity coordinates, the quantum efficiencies and decay times of the phosphors excited under 392 nm are also investigated. The experimental results indicate that the Eu³⁺-doped Sr₃Y(PO₄)₃ phosphors are promising red-emitting phosphors pumped by near-UV light.     

低热固相反应法合成焦磷酸铁钾纳米晶及表征

在表面活性剂PEG-400的存在下,通过室温下充分研磨K4P2O7·3H2O和Fe2(SO4)3的混合物使其进行固态反应,研磨结束后将反应混合物在60℃下保温4 h。然后用去离子水洗去混合物中的可溶性无机盐,最后在90℃下烘干,即得纳米晶KFeP2O7的前驱体。将前驱体煅烧可得到纳米晶KFeP2O7。煅烧产物通过X-射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)和紫外-可见光谱(UV-vis)表征。结果表明,在750℃下煅烧2 h得到的产物为单斜晶系KFeP2O7。紫外-可见光谱分析显示,单斜KFeP2O7对紫外光具有强的吸收能力。     

Solid state reaction synthesis and photoluminescence properties of Dy3+ doped NaGd(MoO4)2 phosphor

Dy³⁺ doped NaGd(MoO₄)₂ phosphors were synthesized by a traditional solid-state reaction route using NH₄HF₂ as a flux. The influence of calcination temperature on the crystal structure and spectral properties was studied, and the optimum calcination temperature for producing Dy³⁺ doped NaGd(MoO₄)₂ phosphor was experimentally confirmed. The concentration quenching of Dy³⁺ fluorescence and excitation-wavelength dependent spectroscopic properties were studied. On the base of both the Van Uitert's and I-H models, the electric dipole–dipole (D–D) interaction was ascribed to be the main physical mechanism responsible for energy transfer between Dy³⁺ ions. It was also discovered that the color coordinates of the Dy³⁺ doped NaGd(MoO₄)₂ phosphor depends on the Dy³⁺ doping concentration and the excitation wavelength.     

Synthesis and photoluminescence properties of CaGd2(MoO4)4:Eu3+ red phosphors

The novel red-emitting Eu³⁺ ions activated CaGd₂(MoO₄)₄ phosphors were prepared by a citrate sol–gel method. The X-ray diffraction patterns confirmed their tetragonal structure when the samples were annealed above 600 °C. The photoluminescence excitation spectra of CaGd₂(MoO₄)₄:Eu³⁺ phosphors exhibited the charge transfer band (CTB) and intense f–f transitions of Eu³⁺ ion. The optimized annealing temperature and Eu³⁺ ion concentration were analyzed for CaGd₂(MoO₄)₄:Eu³⁺ phosphors based on the dominant red (⁵D₀→⁷F₂) emission intensity under NUV (394 nm) excitation. All decay curves were well fitted by the single exponential function. These luminescent powders are expected to find potential applications such as WLEDs and optical display systems.     

Preparation and photoluminescence properties of Eu3+-doped ZrO2 nanotube arrays

Zr–Eu alloy containing 3 at% Eu was prepared by a powder metallurgical method and Eu³⁺-doped ZrO₂ nanotube arrays were prepared by anodising the Zr–Eu alloy. The properties of Eu³⁺-doped ZrO₂ nanotube arrays were studied in contrast to undoped ZrO₂ nanotube arrays under different annealing temperatures. Results showed that the Eu³⁺ ions could not only stabilise the tetragonal phase of zirconium oxide, but also make the crystallite sizes smaller. Annealing temperature exerted a significant influence on the absorbance value, as well as the intensity and position of the photoluminescence peaks. When the excitation wavelength was either 248 nm or 270 nm, the sample annealed at 600 °C displayed the strongest emission peak; while under excitation at 232 nm, the sample annealed at 400 °C exhibited the strongest emission peak.     

Preparation and luminescence properties of Eu2O3 doped glass-ceramics containing NaY(MoO4)2

Eu₂O₃ doped transparent glass-ceramics containing NaY(MoO₄)₂ crystalline phase were prepared via melting-crystallization. The optimum heat treatment condition (660℃/3h) was determined by DSC, XRD, SEM and transmittance curves. The transmittance of glass-ceramic can reach 80 % in the visible region. The emission spectra of Eu₂O₃ doped glass-ceramics consist of Eu³⁺ ions characteristic emission peaks at 591nm (⁵D₀→⁷F₁) and 614nm (⁵D₀→⁷F₂). The optimal doping concentration of Eu₂O₃ in the glass-ceramics is 0.9 mol%, and fluorescence lifetime is 1.37042ms. The change of the ratio of red emission intensity to orange emission intensity leads to the shift of chromaticity coordinates from orange to red region, and the chromaticity coordinate (0.6337, 0.3635) of 0.9 mol% Eu₂O₃ doped glass-ceramic is closest to the standard red light coordinate. The results show that this kind of glass-ceramic is expected to be good red emission material.