纳米氧化锌表面包覆氧化铝复合粉体制备及其光催化活性

Preparation of Al2O3-coated Nano-ZnO Composite Powder for Reducing Photocatalytic Activity

在制备ZnO的前驱物—碱式碳酸锌的过程中原位包覆A1_2O_3,与在ZnO粉体表面包覆的传统工艺相比减少了多次引起粒子团聚的工艺过程,改善了包覆效果.TEM观察表明,包覆的ZnO复合粉体粒径为50nm左右、包覆层厚为3～5nm。XPS分析表明,包覆层为Al_2O_3和ZnO。光催化活性的测试表明,包覆后的纳米ZnO光催化活性得到了明显降低。包覆后的纳米ZnO紫外线吸收性能与未包覆的纳米ZnO基本相同,保证了其优异的紫外吸收性能。

Al2O3-coated nano-ZnO composite powder was obtained by coating precursor in slurry of basic zinc carbonate. The composite powder was examined by UV-VIS and TEM, and its photocatalytic activity was determined by photooxidation of castor oil illuminated under a high pressure mercury lamp. The composite particles are about 50 nm, and coated homogeneous film is 3-5 nm thick. The composite powder has nice ultraviolet-adsorption as good as un-coated nano-ZnO and its photocatalytic activity is reduced significantly. Compared with coating the calcined product ZnO powder surface, less steps are required in this coating process. As a result, the agglomeration during preparation steps is avoided.