Fabrication and characterization of TiO2 nanoparticles conjugated luminescence upconversion nanoparticles


Topel S. D., Topel Ö., Cin G. T.

BIOINTERFACE RESEARCH IN APPLIED CHEMISTRY, vol.8, no.3, pp.3197-3202, 2018 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 8 Issue: 3
  • Publication Date: 2018
  • Journal Name: BIOINTERFACE RESEARCH IN APPLIED CHEMISTRY
  • Page Numbers: pp.3197-3202
  • Keywords: upconversion, rare earths, TiO2 nanoparticles, luminescence, water soluble, DRUG-DELIVERY, SOLAR-CELLS, SIZE, MECHANISM, IONS, ER3+, TM3+
  • Akdeniz University Affiliated: Yes

Abstract

TiO2 nanoparticles conjugated luminescence upconversion (TiO2-UC) nanocomposites have been fabricated by covalently linking of carboxyl-functionalized TiO2and amino-functionalized NaYF4:Yb3+,Er3+,Ce3+upconversion nanoparticles (UCNP) in the presence of N,N'dicyclohexylcarbodiimide(DCC) /4-dimethylaminopyridine(DMAP) coupling reagents. The carboxyl-functionalized TiO2nanoparticles and amino-functionalized UCNPs have been synthesized by hydrothermal method with 5±2 and 55±10 nm in diameter, respectively. In the synthesis of UCNPs, the percentage of stabilizing agent (polyethyleneimine, PEI), the mole ratios of NaCl/NH4F and the co-doping ratio of Ce3+ion have been found to be a significant effecton their size and morphology. Size, morphology, conjugation as well as photo-physical properties of all synthesized nanomaterialshave been characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and fluorescence spectroscopy. UCNPs and TiO2-UCnanocomposites exhibit strong green luminescence at room temperature under 980 nm excitation leadedthe emissions at 440, 520, 540 and 658 nm, representing 2H9/2 4I15/2,2H11/24I15/2, 4S3/24I15/2 and 4F→4I15/2 transitions, respectively. The water dispersible luminescence nanocompositeshaving NIR light utilizing ability are promising for efficient light harvesting and/or bio-imaging applications.

TiO2 nanoparticles conjugated luminescence upconversion (TiO2-UC) nanocomposites have been fabricated by covalently linking of carboxyl-functionalized TiO2 and amino-functionalized NaYF4:Yb3+, Er3+, Ce3+ upconversion nanoparticles (UCNP) in the presence of N, N'-dicyclohexylcarbodiimide (DCC) / 4-dimethylaminopyridine (DMAP) coupling reagents. The carboxyl-functionalized TiO2 nanoparticles and amino-functionalized UCNPs have been synthesized by hydrothermal method with 5 +/- 2 and 55 +/- 10 nm in diameter, respectively. In the synthesis of UCNPs, the percentage of stabilizing agent (polyethyleneimine, PEI), the mole ratios of NaCl/NH4F and the co-doping ratio of Ce3+ ion have been found to be a significant effect on their size and morphology. Size, morphology, conjugation as well as photo-physical properties of all synthesized nanomaterials have been characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and fluorescence spectroscopy. UCNPs and TiO2-UC nanocomposites exhibit strong green luminescence at room temperature under 980 nm excitation leaded the emissions at 440, 520, 540 and 658 nm, representing H-2(9/2) -> I-4(15/2), (2)Hl(1/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2) and F-4 -> I-4(15/2) transitions, respectively. The water dispersible luminescence nanocomposites having NIR lightutilizing ability are promising for efficient light harvesting and/or bio-imaging applications.