An Efficient Bismuth Tungstate Visible-Light-Driven Photocatalyst for Breaking Down Nitric Oxide

This paper reports a photocatalytic removal of 400 ppb level of NO in air under visible light irradiation by utilizing three-dimensional (3D) hierarchical bismuth tungstate (Bi2WO6) microspheres. A facile microwave-assisted hydrothermal method involving bismuth nitrate and sodium wolframate was developed to synthesize the photocatalyst. The Bi2WO6 samples were characterized by using X-ray diffraction (XRD), Brunauer−Emmett−Teller (BET), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Raman and ultraviolet−visible reflectance (UV−vis) spectroscopy. The relationship between the physicochemical property and the photocatalytic performance of the as prepared samples is discussed. The present work demonstrates that the 3D hierarchical Bi2WO6 microspheres are effective visible-light-driven photocatalytic functional materials for air purification.