高热稳定性多孔二氧化钛/石墨烯复合体的制备与光催化性能研究

Study on preparation and photocatalytic performance of high thermally stable porous TiO_2/graphene composites

以硫酸氧钛为钛源,氧化石墨为碳源,采用水热方法制备了高热稳定性多孔二氧化钛/石墨烯复合体材料。利用XRD、Raman、N2吸附、SEM和TEM对复合体材料的结构进行了表征。研究表明高热稳定性多孔二氧化钛均匀复合在石墨烯表面,两者形成了有效的界面耦合。光催化降解高毒性有机污染物2,4-二氯苯酚,经700℃高温焙烧后的样品具有最高的光催化降解效率,2h即可将有机物完全降解,这得益于多孔二氧化钛发达的孔道结构利于反应物和产物的扩散,较高的结晶度以及与石墨烯之间形成的紧密界面耦合有利于光生电荷的分离。这种新颖的具有优异光催化性能的高热稳定性多孔二氧化钛/石墨烯复合体在光催化领域具有较高的应用价值,这种一步水热法合成策略也为构筑其他石墨烯基多孔复合材料提供了新的思路。

Utilizing titanyl sulfate as Ti source and graphite oxide as carbon source,high thermally stable porous TiO2/graphene composites were successfully prepared via hydrothermal method.The structure was characterized by X-ray diffraction (XRD), Raman,N2 adsorption,scanning electron microscope (SEM)and transmission electron microscopy (TEM).The results show that the surface of graphene is covered uniformly by high thermally stable porous TiO2 and both form effective interface coupling. The sample calcined at 700 ℃ exhibits the best photocatalytic property for photocatalytic degradation high toxic 2,4-dichlorophe-nol.The complete photocatalytic degradation can be achieved within 2 h.The high catalytic performance is due to the porous structure favoring the reactants and products diffusion,and high porous TiO2 crystallinity and efficient interface coupling between porous TiO2 and graphene benificial the photogenerated charge carriers separation.This novel high thermally stable porous TiO2/graphene composite will have potential applications in photocatalysis,and the facile one-step hydrothermal strategy offers new i-deas for fabricating other graphene-based porous composites materials.