构建BiVO_(4)/g-C_(3)N_(4)异质结光催化剂及高效去除印染废水中有机污染物

Construction of Z-type Heterojunction BiVO_(4)/g-C_(3)N_(4)Photocatalyst and EfficientRemoval of Organic Pollutants in Printing and Dyeing Wastewater

本研究采用共沉淀法和水热法成功制备出Z型异质结BiVO_(4)/g-C_(3)N_(4)光催化剂。通过X射线衍射(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)和紫外-可见漫反射光谱(UV-vis DRS)方法对制备的样品进行了结构、形貌和光电化学性能表征,并对其可能的光催化反应机理进行了探讨。研究结果表明:与单一的BiVO_(4)/g-C_(3)N_(4)光催化剂相比,Z型异质结BiVO_(4)/g-C_(3)N_(4)光催化剂在可见光下对亚甲基蓝(MB)的降解具有最高的活性,分别是单一的BiVO_(4)和g-C_(3)N_(4)的12倍和2.18倍。经过5次循环实验测试,Z型异质结BiVO_(4)/g-C_(3)N_(4)光催化剂对亚甲基蓝MB的降解率均能达到90%,证明其有良好的稳定性。此外,通过活性物种捕获实验对Z型异质结BiVO_(4)/g-C_(3)N_(4)光催化剂的机理进行研究,结果表明·O_(2)^(-)为最主要的活性物种。本实验为构建其他异质结光催化剂提供了新方法,为除去印染废水中有机污染物提供了新思路。

This study successfully prepared Z-type heterojunction BiVO_(4)/g-C_(3)N_(4)photocatalysts using co precipitation and hydrothermal methods.The structure,morphology and photoelectrochemical properties of the samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Scanning electron microscope(SEM),UV-vis diffuse reflectance spectroscopy(UV-vis DRS),and the possible photocatalytic reaction mechanism was discussed.The results showed that compared with single BiVO_(4)and g-C_(3)N_(4)photocatalysts,BiVO 4/g-C 3N 4 heterojunction photocatalysts had the highest activity for the degradation of methylene blue(MB)under visible light,which is 12 times and 2.18 times higher than single BiVO_(4)and g-C_(3)N_(4),respectively.After 5 cycles of experimental testing,the degradation rate of MB by Z-type heterojunction BiVO_(4)/g-C_(3)N_(4)photocatalyst reached 90%,demonstrated that its good stability.Furthermore,based on the active species capture experiment,the mechanism of Z-type heterojunction BiVO_(4)/g-C_(3)N_(4)photocatalyst was studied,and it was found that·O_(2)^(-)is the most important active species.This experiment provides a new method for constructing other heterojunction photocatalysts and a new approach for removing organic pollutants from printing and dyeing waste water.