微波水热法制备Nd掺杂ZnO光催化剂的研究

摘要

采用微波水热法制备了Nd/ZnO光催化剂，以期提高ZnO的光催化性能。利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、扫描电子显微镜(SEM)、紫外-可见分光光度计(UV-Vis)以及降解亚甲基蓝实验等对样品的结构和性能进行了表征。研究结果表明：制备的ZnO及Nd/ZnO结晶良好，均为六方纤锌矿结构。Nd的掺杂未引起ZnO晶体结构的变化，但引起晶格畸变，使晶胞参数增大，并且促进了ZnO晶体的生长。与ZnO相比，Nd/ZnO的紫外-可见吸收光谱吸收带边发生红移，禁带宽度变小。随着Nd掺杂量的提高，ZnO的光催化性能呈现先升高后降低的趋势，当Nd的掺量为0.20mol%时， Nd/ZnO的光催化活性最高，在紫外光辐照4 h的条件下使得亚甲基蓝的降解率达91.01%。%Nd-doped ZnO photocatalyst was prepared by microwave hydrothermal method in order to improve the photocatalytic performance of ZnO. The microstructure and performance of the samples were characterized by X-ray diffraction (XRD), ifeld emission scanning electron microscope (FESEM), scanning electron microscope (SEM), UV-Vis spectrophotometer (UV-Vis) and photocatalytic degradation of methylene blue. The results showed that all the samples were highly crystallized with a hexagonal wurtzite structure. The doping of Nd did not change the crystal structure of ZnO, but led to the lattice distortion and the increase of cell parameters, and also promoted the growth of ZnO crystals. The doping of Nd led to the redshift of UV-Vis absorption spectrums and the decrease of the band gap at different levels. Also, the photocatalytic performance of Nd/ZnO presented a reduction trend after a period of increase with the content of Nd increased. The Nd/ZnO sample achieved the optimal photocatalytic performance when the Nd doping amount was 0.20mol%, which made the degradation rate of methylene blue reach 91.01% under UV irradiation for 4 h.