Enhanced photocatalytic performance of Ag-Bi4Ti3O12 nanocomposites prepared by a photocatalytic reduction method
Enhanced photocatalytic performance of Ag-Bi4Ti3O12 nanocomposites prepared by a photocatalytic reduction method
复制标题
光催化还原法制备Ag-Bi4Ti3O12纳米复合材料增强光催化性能
DOI：
10.1080/10667857.2017.1371914
复制
发表时间：
2017
影响因子：
3.1
通讯作者：
Feng W
中科院分区：
文献类型：
--
作者：
Zhao X;Yang H;Cui Z;Li R;Feng W
采用光催化还原法制备了尺寸为60 ~ 90 nm的Bi4Ti3O12纳米颗粒。采用x射线粉末衍射、透射电镜、x射线光电子能谱、紫外-可见漫反射光谱、电化学阻抗谱、光致发光光谱和光电流响应等方法对制备的Ag-Bi4Ti3O12复合材料进行了系统表征。结果表明，用银纳米粒子修饰Bi4Ti3O12可以有效地分离光生电子-空穴对。选择RhB作为目标有机污染物，考察其在模拟阳光照射下对Ag-Bi4Ti3O12复合材料的降解行为。与裸Bi4Ti3O12相比，Ag-Bi4Ti3O12复合材料的光催化活性得到了显著增强，其中Ag-Bi4Ti3O12的光催化活性最高，为5·2 wt%。一级反应速率常数表明，5·2 wt% Ag-Bi4Ti3O12的光催化活性比裸Bi4Ti3O12高约2.4倍。以AO、乙醇和BQ分别作为h+、•OH和•的清除剂，考察其对RhB降解的影响。发现只有AO对染料降解有重要的抑制作用，由此得出h+是导致染料降解的主要反应物质。
Bi4Ti3O12 nanoparticles with size of 60–90 nm were decorated with smaller-sized Ag nanoparticles (12–25 nm) by a photocatalytic reduction method. The as-prepared Ag–Bi4Ti3O12 composites were systematically characterised by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, electrochemical impedance spectroscopy, photoluminescence spectroscopy and photocurrent response. It is demonstrated that the decoration of Bi4Ti3O12 with Ag nanoparticles leads to an effective separation of photogenerated electron–hole pairs. RhB was chosen as the target organic pollutant to evaluate its degradation behaviour over Ag–Bi4Ti3O12 composites under simulated sunlight irradiation. Compared to bare Bi4Ti3O12, Ag–Bi4Ti3O12 composites exhibit a significantly enhanced photocatalytic activity and the highest photocatalytic activity is observed for 5· 2 wt% Ag–Bi4Ti3O12. The first-order reaction rate constant suggests that the photocatalytic activity of 5· 2 wt% Ag–Bi4Ti3O12 is about 2· 4 times higher than that of bare Bi4Ti3O12. AO, ethanol and BQ were, respectively, used as the scavengers of h+,• OH and• to investigate their effect on the degradation of RhB. It is found that only AO has an important suppression on the dye degradation, from which it is concluded that h+ is the dominant reactive species causing the dye degradation.