明胶网络模板法合成La_2O_2S纳米颗粒

Gelatin Template Synthesis of La_2O_2S Nano-particles

以明胶高分子网格为模板,硫酸氨为硫化剂,在较低温度下(700℃)通过氢气还原法制备La2O2S纳米颗粒。产物用差热-热重(DTA-TG)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和光致发光(PL)光谱分析方法进行表征。实验表明,明胶网格在稀土氢氧化物沉淀和热分解以及(LaO)2SO4生成过程中,能有效地控制颗粒的形貌,抑制颗粒的长大和团聚。用明胶网络模板法合成的La2O2S相纯度高,粒度均匀,粒子近似球形,大小约为30—50 nm。合成的(La0.95Tb0.05)2O2S和(La0.98Pr0.02)2O2S纳米粒子在水溶液中都观察到绿光发射,分别来源于Tb3+离子5D4到7Fj(j=3,4,5和6)的跃迁发射和Pr3+离子的3P0-3H4和3P1-3H4跃迁发射。

Lanthanum oxysulfide nano-particles have been prepared by using gelatin as the template and ammonium sulphate as the sulfidizing agent at relative low temperatures （700 ℃ ） in H2 atmosphere. The products were characterized by using TG- DTA, XRD, SEM, TEM and photoluminescence （PL） spectra techniques. The experiment results showed that gelatin network can control the morphology of the particles and restrain the growth and aggregation of the particles during the precipitation and decomposition of lanthanide hydroxide precursor and the formation of （LaO）2SO4 phase. Lanthanum oxysulfide nano-particles obtained by the gelatin template method had uniform granularity and were almost spherical in shape with particle size ranging from 30 nm to 50 nm. Green light emissions originating from the transition of Tb^3＋ ion from 5^D4 to 7^Fj （j = 3,4,5 and 6） and the transition of Pr^3＋ ion from 3^P0 to 3^H4 and 3^P1 to 3^H4 were observed in photolumineseenee spectra of the synthesized （La0. 95 Tb0.05 ）2O2S and （La0. 95 Tb0. 05 ）2O2S nano-partieles.