A User-Friendly Method for Synthesizing High-Quality<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>NaYF</mml:mtext></mml:mrow><mml:mn mathvariant="bold">4</mml:mn></mml:msub></mml:mrow></mml:math>:Yb,Er(Tm) Nanocrystals in Liquid Paraffin

Abstract

Application of “green chemistry” concept to synthesize nanomaterials is the current goal in developing new techniques for producing materials in commercial scale. In this study, we reported a low-cost and convenient method for synthesizing high-quality<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>NaYF</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>:Yb,Er(Tm) nanocrystals (NCs) in liquid paraffin. Experimental results indicated that the as-prepared NCs possessed pure<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-phase structure, narrow size distribution, as well as strong up-conversion fluorescence. By varying the doped lanthanides, Er or Tm, the emission color of up-conversion fluorescence was tunable. In comparison to other high-boiling-point organic solvents, liquid paraffin is cheaper and prolific in oil industry. Besides,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mtext>280</mml:mtext></mml:mrow><mml:mo>∘</mml:mo></mml:msup></mml:mrow></mml:math>C was the optimal temperature for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>NaYF</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>:Yb,Er(Tm) synthesis, which was lower than that in the previous reports using other high-boiling-point organic solvents. Accordingly, this user-friendly method will facilitate the synthesis of high-quality lanthanide-doped<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>NaYF</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>NCs in commercial scale.