Hydrothermal synthesis and photocatalytic properties of tantalum pentoxide nanorods

Tantalum pentoxide (Ta2O5) nanorods were hydrothermally synthesized using polyethylene glycol (PEG) as a guiding agent. The nanorods were characterized by X-ray diffraction, scanning and transmission electron microscopies, and diffuse reflectance ultraviolet-visible and photoluminescence spectroscopies. The effects of crystallization duration and Ta2O5/Sr(OH)2 ratio on the product morphology were investigated, and a growth mechanism was proposed. Phase-pure Ta2O5 nanorods with controlled morphology were formed in the presence of PEG and Sr(OH)2, which was necessary to form the nanorods. Sr(OH)2 induced the surface dissolution and re-growth of Ta2O5. PEG induced the anisotropic growth of Ta2O5 by acting as a capping agent. The products were used to photocatalytically degrade rhodamine B under ultraviolet irradiation. The catalytic activity directly correlated with the length-diameter ratio of the Ta2O5 nanorods. A maximum apparent reaction rate constant of 0.156 min−1 was obtained. The Ta2O5 nanorods were stable during photocatalytic reaction and could be recycled several times without loss of activity.

Graphical AbstractTa2O5 nanorods with controllable morphology were successfully synthesized by a facile hydrothermal route in the presence of PEG and Sr(OH)2. As a catalyst in the photocatalytic degradation of rhodamine B, impressive activity can be obtained over the as-synthesized nanorods.Figure optionsDownload as PowerPoint slide