SYNTHESIS AND CHARACTERIZATION OF UNIFORM PRASEODYMIUM DOPED ANATASE TIO2 NANOPARTICLES

Abstract

In this work a new synthesis method of uniform praseodymium doped anatase TiO2 nanoparticles and pseoudoellipsoidal shape is described. The resultant nanoparticles are good candidates to be employed in catalysis, energy storage and photovoltaic energy production applications. The synthesis is a gel-sol process using a shape controlled by seeding of anatase TiO2:Pr. Three doped systems at 1%, 5%, 10% [Pr]/[Ti] molar mass ratio were prepared. Pure anatase system with and without seeds was also synthesized to compare with doped systems. XRD and EDX analysis showed praseodymium inserted in anatase bulk structure for lower doped values, formless structure at the highest doped value, and real doping ratio 2%, 3% and 9% respectively. TEM pictures confirm monodisperse nanoparticles with pseudoellipsoidal shape. The average diameter of the semi-major axis is 14.1±0.6 nm and 16.2±0.7 nm for pure anatase with and without seeds, and 14.0±0.8 nm for the 3% doped system. In order to assess crystalline structure parameters a Rietveld refinement with FULLPROF software was done. Results for 3% doped system shows an interplanar distance of 0.35 nm (this was checked by direct measurements on TEM pictures), an increase in cell volume and similar crystallite size (around 12 nm) respect undoped systems.