g-C3N4/TiO2复合材料光催化降解布洛芬的机制

摘要

In this experiment,titanium trichloride was chosen as the titanium source of TiO2 and dicyandiamide was selected as the precursor of g-C3N4 to prepare the g-C3N4/TiO2 composites.The morphology,elements,and catalytic properties characterization of g-C3N4/TiO2 were characterized by transmission electron microscope (TEM),X-ray diffraction (XRD) and ultraviolet-visible absorption spectrum(UV-vis).The results showed that TiO2 could be attached on the surface of g-C3N4 well.The doping ratio 1:9 of C3N4 and TiO2 showed the highest photocatalytic activity on the degradation of IBU due to the red-shift of the catalyst.The photocatalytic degradation of IBU followed pseudo-first-order kinetics.Acidity increased the photocatalytic degradation of IBU.The quenching experiment demonstrated that the contribution rate of ·OH was 73.7％,indicating that ·OH played a major role in the photocatalytic degradation of IBU.%以TiCl3为TiO2钛源,二聚氰胺为g-C3N4前驱体,制备了g-C3N4/TiO2复合材料;通过透射电子显微镜(TEM)、X射线衍射(XRD)和紫外可见光吸收光谱(UV-vis)等对g-C3N4/TiO2复合材料进行形貌、元素和催化活性的表征.结果表明,TiO2能很好地依附在g-C3N4的表面;吸收光发生了红移,扩大了TiO2的吸收光谱范围;催化剂活性实验研究表明g-C3N4与TiO2按1:9的质量掺杂比例制备出的g-C3N4-10/TiO2复合材料对布洛芬(IBU)的光催化降解效果最好;实验同时研究了g-C3N4-10/TiO2复合材料对IBU光催化降解的影响机制.IBU的光催化反应符合准一级动力学规律;酸性环境下有利于IBU的降解;使用异丙醇作为·OH分子探针,检测到·OH存在于g-C3N4/TiO2光催化体系中,并计算得出·OH的贡献率为73.7％,表明·OH在降解中起到主要作用.