稀土掺杂硼酸盐Bi2ZnB2O7: xDy3+光催化剂的合成及其催化机理

采用高温固相反应法制备了一系列镝离子掺杂Bi₂ZnB₂O₇（BZBO）光催化剂。通过XRD、TEM和HRTEM等手段对BZBO: xDy³⁺材料的结构及形貌等进行了表征，通过RhB溶液在紫外灯下的光降解实验研究了不同浓度镝离子掺杂对BZBO光催化性能的影响。RhB光降解实验结果表明，当Dy³⁺在BZBO中的掺杂量为4%时，BZBO: 4%Dy³⁺具有最好的光降解活性，其光降解活性为纯BZBO的1.56倍。通过光吸收性能分析可知，Dy³⁺的引入增强了BZBO的紫外吸收强度，并稍降低了其禁带宽度。光吸收性能、光致发光光谱、光电流和EIS实验结果表明，BZBO: 4%Dy³⁺的光催化活性增强的主要原因是BZBO中掺杂的镝不仅提高了BZBO光催化剂的光吸收能力，更促进了光生电子-空穴对的分离和转移。因此，在稀土元素和极化电场的作用下，BZBO: 4%Dy³⁺的光催化活性要高于其他所制备的样品。

Photocatalytic mechanism and synthesis of rare earth doped borate Bi2ZnB2O7: xDy3+ photocatalyst

A series of dysprosium doped Bi₂ZnB₂O₇(BZBO) photocatalysts were prepared by high temperature solid-state reaction. The crystal structure and morphology of BZBO: xDy³⁺ were detected by XRD, TEM and HRTEM. Effects of dysprosium doping with different concentration on their photocatalytic performance were investigated by degradation of RhB under UV light irradiation. The RhB photodegradation results revealed that the optimum photodegradation activity of Dy³⁺ doped BZBO (BZBO: 4%Dy³⁺) was 1.56 times higher than pure BZBO. The results of optical absorption indicated that the introduction of Dy³⁺ in BZBO could enhance absorption intensity in UV region and reduced forbidden band width of BZBO. The optical absorption, photoluminescence spectra, photocurrent and EIS experimental results demonstrated that the enhanced photocatalytic activity of BZBO: 4%Dy³⁺ was mainly ascribed to that the doped dysprosium in BZBO could promote the separation and transfer of photogenerated electron-hole pairs and improve photoabsorption ability of BZBO photocatalyst. Thus, BZBO: 4%Dy³⁺ exhibited the highest photocatalytic activity than that of other as-prepared samples under the effects of both rare earth elements and polarization electric field.