可见光催化剂BiOI的制备及其对活性蓝KN-R的降解机理

Synthesis of Visible-Light Induced Photocatalyst BiOI and Its Degradation Mechanism of C.I.Reactive Blue KN-R

采用水热法制备了层状结构的可见光催化剂BiOI,通过X射线衍射、扫描电子显微镜、比表面积分析、紫外可见漫反射光谱对样品进行了表征.深入讨论了可见光照射下BiOI对活性蓝KNR的降解,发现降解曲线符合二级反应动力学方程.用叔丁醇、碘化钾、苯醌分别对羟基自由基(·OH)、空穴(h^+)和超氧阴离子自由基(·O^-_2)进行捕捉,研究了BiOI对活性蓝KN-R的降解机理,发现h^+和·O^-_2在降解反应中起主要作用.

Photocatalyst BiOI with plate structure was synthesized by hydrothermal method. The products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, surface area analysis and UV-Vis diffuse reflectance spectra （DRS）. The photocatalytic performance of BiOI on the decomposition of C.I. reactive blue KN-R under visible light irradiation was studied. It demonstrated that the degradation process obeyed the second-order kinetic model. The possible degradation mechanism was studied by detecting the active species · OH, h^＋ and · O2^- through adding tert-butanol, KI and benzoquinone （BQ）,respectively. The results showed that h^＋ and ·O2^- played an important role in the photocatalytic reaction.