Influence of doping with Co, Cu, Ce and Fe on structure and photocatalytic activity of TiO₂ nanoparticles

In this paper, structural and photocatalytic properties of TiO₂ nanopowders doped with 1 at.% of cerium, cobalt, cooper and iron have been compared. Nanoparticles were synthesized by sol-gel technique and characterized by SEM, EDS and XRD methods. Moreover, their photocatalytic activity was determined based on decomposition of methyl orange. Results were compared with undoped powder. The structural investigations have revealed that all prepared nanopowders were nanocrystalline and had TiO₂-anatase structure. The average size of crystallites was ca. 4 nm to 5 nm. The distribution of the dopant was homogenous in case of all manufactured powders. Moreover, for TiO₂ doped with Co, Ce and Cu, aggregation effect was not as large as for TiO₂:Fe. The results of photocatalytic decomposition showed that self-cleaning activity of all prepared nanopowders was higher as compared to undoped one. Due to the efficiency of these reactions (after 5 hours) nanopowders can be ordered as: TiO₂:Co > TiO₂:Ce > TiO₂:Cu > TiO₂:Fe > TiO₂.