LaPO4:Eu microstructures constructed by nanorods with triangular pores in the ends: a simple mixed-solvothermal synthesis, growth mechanism and optical property

Abstract

Flowerlike LaPO4:Eu microstructures built up of nanorods with triangular pores in the ends have been successfully synthesized by a simple water–ethyleneglycol (EG) mixed solvothermal route in the presence of appropriate amounts of concentrated HNO3 and Eu2O3. Lanthanum nitrate (La(NO3)3) and monopotassium phosphate (KH2PO4) were used as the La3+ ion and the PO43− ion source, respectively. X-Ray powder diffraction (XRD) analyses showed that the product was a mixture of hexagonal and monoclinic phases and could be converted to pure monoclinic phase after calcining at 400 °C for 2 h. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy observations exhibited that the morphology of the product did not change before and after calcination. The optical properties and the thermal stability of the flowerlike LaPO4:Eu microstructures were studied. Experiments showed that the presence of appropriate amounts of concentrated HNO3 had a crucial role in the formation of flowerlike LaPO4:Eu microstructures. Based on a time-dependent shape evolution experiment, a possible growth mechanism of the flowerlike LaPO4:Eu microstructures was proposed.