Eu^3+掺杂NaBi(MoO4)2/TiO2复合纤维制备及其光裂解水制氢

Preparation of Eu^3+-doped NaBi(MoO4)2/TiO2 Composite Fibers and Its Photocatalytic Properties for Water Splitting Hydrogen Evolution

以电纺TiO2纳米纤维为基质,利用水热法制备了异质结型Eu^3+掺杂NaBi(MoO4)2/TiO2复合纤维。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、高分辨透射电镜(TEM)、紫外-可见漫反射(UV-Vis DRS)光谱以及荧光(PL)光谱等分析测试手段对样品的物相、形貌和光学性能等进行表征。以三乙醇胺为电子给体,研究了Eu^3+掺杂NaBi(MoO4)2/TiO2复合纤维光催化裂解水制氢的反应过程。结果表明:NaBi(MoO4)2与TiO2复合形成异质结,使光生电子-空穴对得到较好分离,而Eu^3+掺杂进入NaBi(MoO4)2晶格,部分取代Bi^3+离子,导致晶胞膨胀,在拓宽光谱响应范围的同时,形成光生载流子的浅势捕获阱,进一步促进了光生电荷的产生、转移,有效提高材料的光催化制氢活性。最佳产氢速率达到7.86 mmol·h^-1·g^-1。

By employing electrospun TiO2 nanofibers as substrate,rare earth Eu^3+-doped NaBi(MoO4)2/TiO2 composite fibers were prepared via hydrothermal method.Their composition,morphology and optical properties of the composite fibers were characterized by XRD,SEM,XPS,TEM,UV-Vis-DRS and PL analysis.The photocatalytic water splitting for hydrogen evolution was investigated over Eu^3+-doped NaBi(MoO4)2/TiO2 composite fibers with triethanolamine as an electron donor.The results showed that Eu3+ion can be a substitute for Bi^3+ion in the crystal lattice of NaBi(MoO4)2,resulting in an expansion and distortion of lattice cell and defects.It is believed to benefit from the effective charge generation,transfer and separation at the interface of Eu^3+-doped NaBi(MoO4)2/TiO2 heterojunction.The optimal hydrogen evolution rate reaches 7.86 mmol·h^-1·g^-1.