| Rare-earth nano-compounds were attracted by scientists due to their particular physical and chemical properties. Hierarchical europium oxalate Eu2(C2O4)3·10H2O micro-particles, hierarchical lanthanum oxalate La2(C2O4)3`10H2O micropaticles , lanthanum oxalate La2(C2O4)3`10H2O microtube and flower-like NaY(MoO4)2 were synthesized through several methods. The products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and photoluminescence (PL). The possible formation mechanism of products were discussed.1. Hierarchical europium oxalate Eu2(C2O4)3·10H2O micro-particles were synthesized through a simple precipitation method at room temperature in present of trisodium citrate (Na3Cit). The influence of experiment parameters on the morphology of products has been investigated, and it can be reached a conclusion that room temperature, 24h and 1.2mmol Na3Cit are the preferable experiment parameters to synthesize the regular hierarchical Eu2(C2O4)3·10H2O micro-particles. A possible formation mechanism of the regular hierarchical Eu2(C2O4)3·10H2O was suggested. Furthermore, the optical property of the hierarchical Eu2(C2O4)3·10H2O micro-particles was studied, and the one efficient and sharp PL emission peak at around 616nm shows a potential application as a red phosphor for light-emitting diodes. This simple approach can be extended for the synthesis of other lanthanide oxalates.2. Hierarchical lanthanum oxalate Eu2(C2O4)3·10H2O micropaticles and lanthanum oxalate La2(C2O4)3`10H2O microtube were synthesized through a simple precipitation method at room temperature in present of trisodium citrate (Na3Cit) and in a solvent system of mixture of water and ethanol (volume ratio 1:1). The influence of experiment parameters, such as reaction time, volume ratio of water and ethanol and the dosage of the urea, on the morphology of products has been investigated, and it can be reached a conclusion that room temperature, 24h, volume ratio 1:1 and 1.2mmol Na3Cit and 0.9mmol are the preferable experiment parameters to synthesize the regular hierarchical La2(C2O4)3`10H2O micro-particles and La2(C2O4)3`10H2O microtube respectively. A possible formation mechanism of the regular hierarchical La2(C2O4)3`10H2O and microtube were suggested. This simple approach can be extended for the synthesis of other lanthanide oxalates.3. Flower-like NaY(MoO4)2 microparticles were synthesized through microwave-assisted hydrothermal method. The influence of experiment parameters on the morphology of products has been investigated, and it can be reached a conclusion that 160℃, 24h, 40s and 400W are the preferable experiment parameters to synthesize the regular flower-like NaY(MoO4)2.A possible formation mechanism of the regular h flower-like NaY(MoO4)2 was suggested. Furthermore, the optical property of the NaY(MoO4)2:Eu3+ micro-particles was studied。The result showed that 5% was the preferable of the dosage of Eu3+ and the one efficient and sharp PL emission peak at around 612nm. And it is a potential application as a red phosphor for light-emitting diodes. This simple approach can be extended for the synthesis of other lanthanide molybdates.
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