Facile preparation of hierarchical Nb2O5 microspheres with photocatalytic activities and electrochemical properties

Hierarchical flower-like Nb2O5 microspheres have been prepared via a facile hydrothermal approach without any additives. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to clarify the structure and morphology of the Nb2O5 microspheres. Structure and morphology evolution mechanisms have been proposed for the hierarchical structure in detail. During the symmetric Ostwald ripening, the resultants formed aggregates composed of two-dimensional nanoflakes as building blocks. Photocatalytic activity of the as-prepared Nb2O5 microspheres was evaluated by the photodegradation of Rhodamine B (RhB), and over 90% of RhB was degraded within 30 min under the irradiation of UV light. The as-prepared Nb2O5 exhibits higher photocatalytic activity than commercial Degussa P25. Moreover, Nb2O5 was tested as an anode material of lithium-ion batteries, which displayed high reversibility and excellent rate stability at a current density of 50 mA g(-1).