氮掺杂Bi2O3光催化剂的制备及其可见光催化性能

以硝酸铋和六次甲基四胺为原料,采用沉淀法合成了不同氮掺杂量的Bi2O3(N-Bi2O3)粉体,并采用XRD、FT-IR、XPS、UV-Vis、PL手段对其晶相结构和光谱特征等进行了表征.研究结果表明,未掺杂Bi2O3为单斜相α-Bi2O3,氮掺杂Bi2O3则为四方相β-Bi2O3和Bi5O7NO3组成的混晶,氮原子替代了Bi2O3晶格中部分氧原子,形成了Bi N键而稳定存在.氮掺杂能促进β-Bi2O3的生成.与未掺杂Bi2O3粉体相比,氮掺杂样品的吸收带边发生了明显红移,荧光强度明显减弱.甲基橙在可见光下的降解实验表明,氮掺杂Bi2O3具有良好的可见光催化活性.

Preparation and Visible Light Responsive Photocatalytic Activity of Nitrogen-doped Bi2O3 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.