为了提高可见光的光催化效率，以ZnCl₂、Co（NO₃）₂·6H₂O、NaOH为原料，利用共沉淀法合成高结晶性的钴掺杂摩尔分数为1%~5%的氧化锌粉末。利用X射线衍射、扫描电子显微镜、紫外-可见吸收光谱等手段对钴掺杂的氧化锌粉末样品的形貌、结构和光学性质进行表征。结果表明，合成的氧化锌粉末在整个可见光区都有吸收。当钴掺杂摩尔分数为3%时纳米氧化锌光催化活性最优，光催化反应速率常数为1.739 6×10^-3 min^-1。基于第一性原理计算了掺钴氧化锌晶体的能带结构，结果表明，位于650 nm的吸收峰来源于氧化锌中价带到杂质能级或杂质能级到导带的电子跃迁。掺钴氧化锌可增加可见光的光催化效率。

In order to improve the photocatalytic efficiency of visible light,highly crystalline Co-doped ZnO powders with different Co²⁺ doping concentrations (1 mol%-5 mol%) are prepared by a co-precipitation method using ZnCl₂,Co(NO₃)₂·6H₂O and NaOH as reactants.The morphology,crystal structure and optical property of the Co-doped ZnO samples are characterized by X-Ray diffraction,scanning electron microscopy and UV-Vis absorption spectroscopy.It is indicated that the resultant ZnO powders have an absorption band in the whole visible light region.ZnO powders with a Co-doping concentration of 3 mol% exhibits the highest photocatalytic activity with its first-order rate constant of 1.739 6×10^-3 min^-1.The band structures and defect level of ZnO are calculated based on first principle.It is found that the sharp absorption peak at 650 nm can be assigned to the transitions of ZnO electron from its valence band to impurity level or from impurity level to the conduction band.The experimental results show that Co-doped ZnO may help visible light increase photocatalytic efficiency.

蔡磊(1993-),男,硕士研究生,研究方向为光催化,996377531@qq.com