Investigations of TiO2 nanoparticles surface-doped with Eu in aqueous fluids to high P-T conditions
A hydrothermal reactor has been used for surface doping of anatase TiO2 nanoparticles (∼ 13 nm across) with Eu3+ ions in aqueous fluids to 370 °C and ∼20 MPa. XRD and Raman measurements made both before and after hydrothermal treatment with Eu show that the anatase structure of the TiO2 nanoparticles (NPs) is preserved. SEM imaging, combined with XRD indicates that the size and overall morphology of the TiO2 nanoparticles is preserved subsequent to hydrothermal treatment in the presence of Eu. The photoluminescence occurring in the 400 to ∼700 nm range of the (as prepared) Eu surface-doped TiO2 NPs are red-shifted by ∼ 50 nm and reduced in intensity relative to the photoluminescence of TiO2 NPs.