Direct synthesis of undoped/doped SrTiO3 nanoparticles from solution

Abstract

Directly crystallizing strontium titanate (SrTiO3) nanoparticles from a solution near room temperature poses a challenge due to Ti ions easily form colloids and result in amorphous products. It is also difficult to ensure the uniform incorporation of the dopants into the lattice during synthesis of doped samples. This study successfully achieved this task using the direct synthesis from solution (DSS) method. Both undoped SrTiO3 nanoparticles and Fe-doped one were synthesized in an ethanol solution at the temperatures ranging from 60 to 80 °C, resulting in homogeneous grains with an average size of approximately 15 nm. Despite the solubility limit of Fe3+ in bulk SrTiO3 being around 2.5 %, we successfully synthesized Fe-doped SrTiO3 nanocrystals with high doping level even at a dose of 10 %.The tribocatalytic performance of both undoped and Fe-doped SrTiO3 nanoparticles was evaluated for methylene blue degradation in a solution. Undoped SrTiO3 nanoparticles showed similar catalytic performance to P25. In contrast, Fe-doped SrTiO3 nanoparticles exhibited much higher catalytic performance. This enhanced catalytic performance is attributed to the presence of oxygen vacancies, which are introduced by doping Fe3+ into the SrTiO3 lattice to substitute the Ti ion.