Niobium doping induced morphological changes and enhanced photocatalytic performance of anatase TiO₂

In order to develop high-performance photocatalysts that are easy to produce even in industrial quantities, we developed a facile method of preparing niobium-doped titanium dioxide (Nb:TiO₂) by hydrothermal synthesis and followed by thermal annealing treatment. Niobium-ion doping has been considered as an effective way to improve Nb:TiO₂ performance for applications in photocatalysis. Niobium-ion doping of anatase TiO₂ induced the morphological changes of Nb:TiO₂. Morphological analysis shows sub-microscale fibers at doping concentration lower than 1.00 mol% and nanoscale rods at the doping concentration higher than 1.00 mol %. For the catalyzed photodegradation of methyl orange under visible light irradiation, 0.50 mol% Nb:TiO₂ shows the highest activity among the synthesized Nb:TiO₂ specimens. Also, for photocatalytic hydrogen generation, its photocatalytic activity is even higher than that of commercial TiO₂-P25. In this study, we demonstrated the fabrication of a series of superior Nb:TiO₂ specimens. It is a reasonable alternative to commercial TiO₂ materials for various applications in the decomposition of organic dyes under visible light irradiation.