The Role of Nb Addition in TiO2 Nanoparticles: Phase Transition and Photocatalytic Properties

This paper reports an experimental investigation on the effects of Nb addition on the phase transformation and photocatalytic properties of TiO2 nanoparticles. Differential thermal analysis, Raman spectroscopy, X-ray diffraction measurements reveal that Nb addition retarded the anatase-to-rutile phase transition. Photocatalysis experiments indicate an enhancement of the degradation of methylene blue and rhodamine B dyes with the addition of Nb to TiO2 lattice. This behavior was attributed to the presence of Nb ions acting as active sites formers as well as the removal of organic species, since the presence of hydroxyls groups remained unchanged, as revealed by X-ray photoelectron spectroscopy.