Preparation of N-Doped Bi2WO6 Microspheres for Efficient Visible Light-Induced Photocatalysis

The N-doped bismuth tungstate (Bi2WO6) photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samples were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV Vis diffuse reflectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B (RhB) solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experiments which revealed that the holes were the main active species of N-doped Bi2WO6 products in aqueous solution under visible light irradiation, rather than .OH and O-2(center dot-). With the assistance of H2O2, the photocatalytic activity for degradation of RhB could be further improved because H2O2 reacted with conduction band electrons to generate more hydroxyl radicals.