A stable single-crystal Bi₃NbO₇ nanoplates superstructure for effective visible-light-driven photocatalytic removal of nitric oxide

In this study, bismuth niobate (Bi₃NbO₇) single-crystal nanoplates superstructure (BNS) was prepared via a facile hydrothermal route without adding any surfactants and templates by using bismuth citric and niobium pentoxide as precursors. The as-prepared products were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) nitrogen adsorption–desorption, X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectrum (DRS). The characterization results revealed that the BNS nanostructures were self-assembled of single crystalline nanoplates under hydrothermal environment. These BNS exhibited excellent visible-light-driven (λ > 420 nm) photocatalytic performances for the removal of gaseous nitrogen monoxide (NO), the removal of NO reached 42.3% in 40 min at the presence of BNS, which was much higher than those of C-doped TiO₂ (25% of NO removal), the InVO₄ hollow microspheres (25% of NO removal), as well as the BiOBr nanoplates microspheres (30% of NO removal). Close investigation indicated that plenty of pores existed in the aggregation of BNS superstructures, which could serve as efficient transport paths for NO molecules and harvesting of more light. Moreover, the BNS exhibited high stability during multiple runs of photocatalytic removal of NO due to their special superstructures. The study provides a facile method to synthesize BNS with high efficiency and high stability in the visible-light spectral range. Copyright © 2012 Elsevier B.V. All rights reserved.