Preparation and Visible Light Responsive Photocatalytic Activity of Nitrogen-doped Bi_2O_3 Photocatalyst

Bi2O3 photocatalysts doped with different amounts of nitrogen were synthesized by a precipitation method using bismuth nitrate and hexamethylenetetramine as precursors.The as-synthesized samples were characterized and analyzed by XRD,FT-IR,XPS,UV-Vis and PL.The results indicate that the undoped Bi2O3displays a single monoclinic phase.While the N-doped Bi2O3 samples are mixed crystals,which were composed of tetragonal β-Bi2O3 and Bi5O7NO3 phases.The oxygen in the lattice of Bi2O3is partially substituted by nitrogen atom,existed stably in the form of Bi N bond.Meanwhile,nitrogen dopant promotes the formation of β-Bi2O3phase.Compared with undoped Bi2O3,the light absorption property of N-doped Bi2O3 has apparently extended into visible light region and the fluorescence intensity decreases evidently.Furthermore,the photodegradation performance of methyl orange shows that N-doped Bi2O3 samples have excellent visible light photocatalytic activity.