Preparation and photocatalytic performance of iodine-doped NaTaO3 nanoparticles

Iodine-doped NaTaO3 nanoparticles were prepared by hydrothermal conditions and explored as the visible-light-driven photocatalysts for photodegradation of methylene blue in water. It is found that I-doped NaTaO3 showed photodegradation efficiency superior over the un-doped NaTaO3. UV-Vis diffuse reflectance spectra indicate that the absorption edges shifted towards longer wavelength with increasing the iodine concentration. The energy band structure and the transient behavior of the photogenerated charge carriers for both un-doped and doped NaTaO3 powders were investigated using density functional theory. The improved photocatalytic activity under visible light for I-doped NaTaO3 may be caused by both the broadening of valence band that inhibited the recombination of e-h+ pairs and the narrowing of energy band gap due to the much negative energy levels in the bottom of conduction bands.