A novel approach to obtain highly intense self-activated photoluminescence emissions in hydroxyapatite nanoparticles

作者：Machado Thales R; Sczancoski Julio C; Beltran Mir Hector; Nogueira Icamira C; Li Maximo S; Andres Juan; Cordoncillo Eloisa; Longo Elson

来源：Journal of Solid State Chemistry, 2017, 249: 64-69.

DOI：10.1016/j.jssc.2016.12.018

• Hydroxyapatite
• Chemical precipitation
• Photoluminescence
• Electronic structure
• Defects
• Order-disorder

Defect-related photoluminescence (PL) in materials have attracted interest for applications including near ultraviolet (NUV) excitable light-emitting diodes and in biomedical field. In this paper, hydroxyapatite [Ca-10(PO4)(6)(OH)(2)] nanorods with intense PL bands (bluish- and yellowish-white emissions) were obtained when excited under NUV radiation at room temperature. These nanoparticles were synthesized via chemical precipitation at 90 degrees C followed by distinct heat treatments temperatures (200-800 degrees C). Intense and broad emission profiles were achieved at 350 degrees C (380-750 nm) and 400 degrees C (380-800 nm). UV-Vis spectroscopy revealed band gap energies (5.58-5.78 eV) higher than the excitation energies (similar to 3.54 and similar to 2.98 eV at 350 and 415 nm, respectively), confirming the contribution of defect energy levels within the forbidden zone for PL emissions. The structural features were characterized by X-ray diffraction, Rietveld refinement, thermogravimetric analysis, and Fourier transform infrared spectroscopy. By means of these techniques, the relation between structural order-disorder induced by defects, chemical reactions at both lattice and surface of the materials as well as the PL, without activator centers, was discussed in details.

• 出版日期2017-5