一维WO3-ZnO异质结构的合成及生长机理研究

Synthesis and growth mechanism of WO_3-ZnO heterostructure

本文采用两步水热法成功合成出一维WO_3-ZnO分级异质结构。TEM表征发现ZnO纳米棒在WO_3纳米带表面均匀排列,ZnO纳米棒和WO_3均各自沿着[0001]方向生长,且二者之间存在特定的取向关系,即生长方向成44°或者136°角。晶体学分析表明在ZnO和WO_3之间存在失配度很小的取向关系,即(0001)_(WO3)//(1102)_(ZnO)和(112 2)_(WO3)//(0001)_(ZnO),以及经过翻转后出现的(0001)_(WO3)//(1102)_(ZnO)和(1122)_(WO3)//(0001)_(ZnO)。根据实验和晶体学分析结果,本文认为ZnO棒在WO_3纳米带上的生长机理是符合Volmer-Weber模型的外延生长。

We report the synthesis of WO_3-ZnO heterostructured nanobelt via a simple two-step hydrothermal method. TEM characterization revealed that ZnO nanorods uniformly and regularly grew on the surface of WO_3 nanobelt. Both WO_3 nanobelt and ZnO nanorods grew along their [0001]directions respectively,with a specific crystallographic relationship that the angle between [0001]_(ZnO) and [0001]WO_3 was either 44° or 136° with(0001)_(WO3)//(1102)_(ZnO),(112 2)_(WO3)//(0001)_(ZnO),(0001)_(WO3)//(1102)_(ZnO) and(112 2)_(WO3)//(0001)_(ZnO). According to the experiment results and crystall ographic analysis,an epitaxial growth mechanism based on Volmer-Weber heteroepitaxial growth model is proposed for ZnO nanorodsgrown on WO_3 nanobelt.