海胆形氧化锌纳米结构的制备与光催化性能

以Zn(AC)2.2H2O为原料,NH3.H2O为络合剂,在NaBH4辅助下140℃水热反应2 h制备出ZnO纳米棒自组装的海胆形结构。采用X射线衍射仪、扫描电镜和透射电镜对产物进行表征。结果表明,海胆形ZnO结构的直径约为3～17μm,它是由直径约为100 nm,长度约为500 nm～3μm范围的ZnO纳米棒自组装而成。提出了ZnO纳米棒自组装海胆形结构的可能生长机理。NaBH4与溶液中的少量H+结合生成H2气泡,ZnO纳米晶吸附在H2的气液界面形成了纳米颗粒自组装的微球,随着反应时间的延长,组装成微球的ZnO纳米颗粒沿[0001]方向取向生长成ZnO纳米棒,最终形成ZnO纳米棒自组装的海胆形颗粒。室温下以海胆形ZnO纳米结构和ZnO纳米棒为光催化剂,以偶氮染料甲基橙作为光催化研究对象,紫外光照70 min,对甲基橙的降解率分别为97%和67%。

Synthesis and photocatalytic properties of ZnO nanorods-based urchin nanostructure

The urchin ZnO nanostructure were obtained by a simple hydrothermal reaction of Zn(AC)2 with NH3 and NaBH4 at 140℃ for 2 h.The products were characterized by X-ray diffraction,scanning electron microscopy and transmissom electron microscopy.The results showed that the urchin ZnO nanostructure with the diameters of 3~17μm are assembled from one-dimensional nanorods with the diameter and length of 100 nm and 500 nm~3μm.Possible growth mechanism of the urchin ZnO nanostructure were proposed.NaBH4 may react with a small amount of H+ in the reaction system,Lots of microbubbles of H2 produced.Small ZnO nanodots may aggregate around the gas–liquid interface between H2 and water to form hollow ZnO nanodot-based microspheres,The constituent ZnO nanodots will evolve into ZnO nanorods along the direction by oriented attachment to obtain the urchin ZnO nanostructure.Photocatalytic activities of the urchin ZnO nanostructure and ZnO nanorods in the degradation of methyl orange were investigated.The degradation rate of the urchin ZnO nanostructure and ZnO nanorods under 70 min UV irradiation,were 97% and 67%,respectively.