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

Abstract

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.