SnO_2/Bi_2MoO_6复合光催化剂的制备及可见光催化性能研究

Synthesis of SnO_2/Bi_2MoO_6 photocatalysts and their visible-light photocatalytic activities

采用简单的水热法通过引入少量的SnO_2制备出不同比例的SnO_2/Bi_2MoO_6异质结光催化剂.通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外光谱(FT-IR)、荧光光谱(PL)、紫外可见漫反射光谱(UV-vis DRS)现代研究技术对所制备的光催化剂进行表征测试,分析了样品的形貌尺寸、晶体结构、光学性质等.以龙胆紫为目标污染物,在5 W的LED(发光二极管)灯下进行光催化降解实验,并研究动力学过程,系统地评价催化剂的光催化性能.实验结果表明,所合成的SnO_2/Bi_2MoO_6复合材料对龙胆紫的降解均比纯的Bi_2MoO_6有明显的提高,其中7%SnO_2/Bi_2MoO_6拥有最佳的光催化活性,该复合物对龙胆紫的降解速率常数约是纯Bi_2MoO_6的2.7倍、纯SnO_2的17倍.进一步通过电子自旋共振(ESR)检测光催化反应中的活性物种,并提出可能的光催化机理.

SnO2/Bi2 MoO6 heterojunction photocatalysts were synthesized with different mass ratio.The as-prepared materials were characterized via XRD,SEM,TEM,FT-IR,PL and UV-VIS DRS techniques.The photocatalytic activities were evaluated using Crystal violet as model pollutant under 5 W LED light irradiation.The results showed that the photocatalytic activities of SnS2/Bi2 MoO6 composites were significantly improved,especially for the 7% SnS2/Bi2 MoO6.The degradation rate constant of 7% SnS2/Bi2 MoO6 was about 2.7 times that of pure Bi2 MoO6 and 17 times that of SnO2.Furthermore,the active species during the degradation process were detected via ESR（electron spin resonance）and the possible photocatalytic mechanism was proposed.