氧化锌量子点敏化氧化铈的制备及可见光催化降解罗明丹B

ZnO QDs Sensitized CeO2 for Enhanced Photodegredation of RhB under Visible-light

摘要:

采用溶胶-凝胶法合成氧化锌量子点（ZnO QDs），将之浸渍负载于氧化铈（CeO2）微球上，制备了ZnO QDs修饰的CeO2可见光催化剂ZnO QDs/CeO2。通过XRD、TEM、SEM表征了ZnO QDs/CeO2的结构和形貌，采用降解罗明丹B（RhB）实验考察了ZnO QDs/CeO2的可见光催化性能，通过电化学阻抗（EIS）、紫外可见吸收光谱（UV-Vis）测试了ZnO QDs/CeO2的光电性能。实验表明，直径6~9 nm的ZnO QDs均匀分布在直径800 nm的CeO2微球表面，ZnO QDs/CeO2的光响应范围拓展到550 nm。1 g CeO2负载0.02 g的ZnO QDs制备的0.02 ZnO QDs/CeO2具有最优的光催化降解RhB的性能，50 mg的0.02 ZnO QDs/CeO2在可见光照射下，催化降解50 mL的0.05 mmol/L的RhB溶液，90 min时RhB的降解率为94%，而同条件下，CeO2和ZnO QDs的RhB的降解率为20%和55%。空穴（h+）是ZnO QDs/CeO2光催化降解RhB的最主要活性物种。

Abstract:

In this paper, zinc oxide quantum dots (ZnO QDs) were synthesized using the sol-gel method, and loaded onto cerium oxide microspheres (CeO2) through an impregnation process, resulting in the preparation of ZnO QDs modified cerium oxide binary composite material (ZnO QDs/CeO2). The structure and morphology of the composite material were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), and other methods. The efficiency of the degradation of rhodamine B was tested under visible light, and the photoelectrical performance of the composite material was characterized using EIS、UV-vis. The experimental results are as follows: the diameter of ZnO QDs was 6-9 nm, the diameter of CeO2 microspheres was 800 nm, and ZnO QDs were uniformly distributed on the surface of CeO2, extending the light response range of the composite material to 550 nm. The efficiency of the ZnO QDs/CeO2 composite for the degradation of rhodamine B under visible light was twice that of CeO2. Through the study of the constitutive relationship, it was found that the introduction of ZnO QDs led to an increase in the light absorption range of the composite material and an improvement in the efficiency of photoinduced electron-hole separation, demonstrating outstanding photocatalytic performance.