rGO/TiO2/BiOI异质结的制备及光催化性能

Preparation and visible-light driven photocatalytic activity of the rGO/TiO2/BiOI heterostructure for methyl orange degradation

采用水热法制备了不同比例rGO/TiO2/BiOI三元复合物,以甲基橙为模拟污染物考察了样品的光催化性能,用扫描电子显微镜、X射线衍射仪、紫外-可见漫反射光谱仪、X射线光电子能谱仪和电化学方法对样品结构和性能进行了表征。结果表明,可见光照射下,Bi/Ti摩尔比为80%的rGO/TiO2/BiOI复合物,在20 min时对甲基橙的降解率达到98%;表明以层状的石墨烯(rGO)为基底,TiO2纳米颗粒均匀附着在BiOI纳米片上,形成了以石墨烯为基底的异质结,异质结在可见光区有较强吸收,改善了光生载流子的分离效率,加快了载流子的迁移速率,从而提高了催化剂的光催化活性。

Reduced graphene oxide(rGO)/TiO2/BiOI ternary composites with different Bi/Ti molar ratios were prepared by a hydrothermal method. Their photocatalytic activities were investigated using methyl orange as a simulated pollutant. SEM, XRD, UV-vis diffuse reflectance spectroscopy, XPS and electrochemical tests were used to characterize their microstructures, light absorption properties and the mobility of photogenerated carriers. Results show that under visible light irradiation, the rGO/TiO2/BiOI composite with a Bi/Ti molar ratio of 80% exhibits a highest degradation rate of 98% for methyl orange within 20 min. The TiO2 nanoparticles are uniformly attached to BiOI nanosheets that are stacked on rGO sheets to form a heterostructure. The heterostructured rGO/TiO2/BiOI has strong visible light absorption, which improves the separation efficiency of the photogenerated carriers and accelerates the carrier migration rate, thus increasing the photocatalytic activity of the catalyst.