Soft-Templated Room Temperature Fabrication of Nanoscale Lanthanum Phosphate: Synthesis, Photoluminescence, and Energy-Transfer Behavior

We herein report a simple and effective soft template mediated synthesis protocol for the room temperature preparation of highly crystalline cerium (Ce 3+ ) and terbium (Tb 3+ ) doped lanthanum phosphate (LaPO 4 ) nanorods (NRs) and nanoflowers. Anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/ n -alkane soft template was chosen since it forms stable reverse micelles (RMs). Transmission electron microscopy (TEM) analysis corroborated successful formation of LaPO 4:Ce 3+,Tb 3+ NRs having different aspect ratios (ranging from 2.8:1 to 7.6:1) under varying reaction conditions. The crystalline nature of the nanomaterials (NMs) was ascertained by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and small-area electron diffraction (SAED) studies. Energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopy further verified the elemental existence of the desirably synthesized nanostructures. Experimental results from thermogravimetric-differential thermal analysis (TG-DTA) revealed thermal stability of the NRs up to 800 °C. The prepared NRs exhibit strong yellowish-green photoluminescence (PL) at 544 nm ( 5 D 4 → 7 F 5 ) when excited at 270 nm. Furthermore, time-resolved decay analysis along with steady-state PL measurements indicated an efficient energy transfer (ET) phenomenon between Ce 3+ and Tb 3+ ions doped in LaPO 4 (LAP) host matrix.