MoO3-C3N4复合光催化剂的可见光下高效催化降解甲基橙

摘要

High performance MoO3-C3N4 photocatalysts were prepared by impregnation method with (NH4)6Mo7O24·4H2O and C3N4 as precursors.The MoO3-C3N4 photocatalysts were characterized by X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FT-IR),high resolution transmission electron microscopy (HRTEM) and nitrogen physisorption isotherm.And methyl orange (MO) degradation was chosen to test the photocatalytic performance of MoO3-C3N4.It was found that all MoO2-C3N4 samples showed very high surface area,exhibited high photocatalytic activity for MO degradation under visible light irradiation and the content of MoO3 affected the photocatalytic activity.The rate constant of 1.60％(w/w) MoO3-C3N4 was 50 times higher than that of pure C3N4.The enhancement of photocatalytic activity over the heterojunction catalyst could be directly attributed to the Zscheme photo-generated charge carrier transfer process,which contributes to suppressed recombination rate of photogenerated electron-hole pairs and prolonged lifetime of charge carriers caused by hybridization of MoO3.%以钼酸铵和C3N4为前驱体,利用浸渍法成功制备了高性能MoO3-C3N4复合光催化剂,利用X射线衍射(XRD)、傅里叶红外(FT-IR)、高分辨电镜(HRTEM)及N2吸附-脱附曲线等测试手段对所得MoO3-C3N4光催化剂进行了结构和形貌表征.以可见光下光催化降解甲基橙反应表征MoO3-C3N4的光催化活性.实验结果表明,MoO3-C3N4光催化剂具有非常好的光催化降解性能,且MoO3含量对反应活性产生显著影响.当MoO3含量为1.6％(w/w)时光催化活性最好,其速率常数达到C3N4的50倍.通过研究发现该复合催化剂的高活性来自于其Z型光生载流子传输过程,抑制了光生电子空穴对的复合并延长了引入MoO3产生的载流子的寿命.