铁酸铋可见光催化材料的可控合成及其光电化学性能研究

发布时间：2018-04-29 14:00

本文选题：铁酸铋 + 形貌调控　；参考：《青岛大学》2015年硕士论文

【摘要】：铁酸铋是一种很有潜力的具有可见光响应的光催化材料,其中Bi2Fe4O9是一种带隙在2.0 eV左右的典型的铁酸铋材料。但是,其光催化性能依旧很低,这和铁酸铋的表面状态有很大的关系。本论文中,在活性晶面构建、形貌调控以及表面修饰的基础上,我们通过调控铁酸铋表面原子结构及相应的载流子转移来提高其光催化性能。我们制备了具有高比例(001)晶面的Bi2Fe4O9材料以及Bi2Fe4O9/还原氧化石墨烯(Bi2Fe4O9-RGO)复合材料。通过XRD、SEM、TEM、XPS等手段对材料进行了表征,并测试了其在可见光下的光电化学性能。在水热过程中通过使用NaOH作为形貌调控剂,制备出了微米方块状和微米片状Bi2Fe4O9材料。HRTEM结果表明微米片状的Bi2Fe4O9相对于微米方块状的Bi2Fe4O9具有更大比例的(001)晶面。在可见光和全光照射下,(001)晶面占优的Bi2Fe4O9微米片的光电流密度有着显著的提升,表明(001)晶面具有更高的光催化活性。我们在一种新的合成路线中,以氧化石墨烯作为模板剂,制备出了超薄的Bi2Fe4O9-RGO复合材料。通过形貌调控、表面修饰以及降低载流子复合几率,对于表面负载了还原氧化石墨烯的Bi2Fe4O9,其在可见光下的光电化学性能得到了明显加强。通过光电解水产氧的测试表明Bi2Fe4O9-RGO复合材料具有优异的光催化活性。
[Abstract]:Bismuth ferrate is a potential photocatalytic material with visible light response, in which Bi2Fe4O9 is a typical bismuth ferrate material with a band gap of about 2.0 EV. However, the photocatalytic activity of bismuth ferrate is still very low, which is related to the surface state of bismuth ferrate. In this thesis, we improve the photocatalytic properties of bismuth ferrate by regulating the atomic structure and carrier transfer on the surface of bismuth ferrate on the basis of active crystal surface construction, morphology regulation and surface modification. We have prepared Bi2Fe4O9 materials with high proportion of crystal plane and Bi2Fe4O9/ reduced graphene oxide Bi2Fe4O9-RGOcomposites. The materials were characterized by means of XRDX SEM Tem XPS and their photoelectrochemical properties were tested under visible light. By using NaOH as morphology regulator in hydrothermal process, micron-shaped and micron-shaped Bi2Fe4O9 materials were prepared. The results show that micron-shaped Bi2Fe4O9 has a larger proportion of crystal planes than micron-shaped Bi2Fe4O9. The photocurrent density of the Bi2Fe4O9 micron wafer with dominant crystal plane under visible and full light irradiation has been significantly increased, indicating that the crystal mask has higher photocatalytic activity. Ultrathin Bi2Fe4O9-RGO composites were prepared by using graphene oxide as template in a new synthesis route. The photochemical properties of Bi _ 2FE _ 4O _ 9 loaded with reduced graphene on the surface were obviously enhanced under visible light by means of morphology control, surface modification and reduction of carrier recombination probability. The photocatalytic activity of Bi2Fe4O9-RGO composite was proved by photodegradation of aquatic oxygen.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TQ135.32

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