Synthesis and characterization of ZnO nanowires/Ag microplates heterostructures and their enhanced photocatalysis performance

• Main Authors: Chang, Cheng-Wei, 張正偉
• Other Authors: Yen, Ta-Jen
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/54012138217187266747

碩士 === 國立清華大學 === 材料科學工程學系 === 100 === Ag/ZnO heterostructures are versatile materials capable of transferring interfacial charge transfer and suppressing electron-hole pairs recombination. Recently, great efforts have been made to prepare Ag/ZnO heterostructures with various morphologies such as clusters (particles-to-particles) and dendrites (wires-to-wires). We herein report a novel heterostructure of ZnO nanowire arrays growing on single crystalline polygonal Ag microplates which provides the merits of the antireflection layer for ZnO nanowire arrays and the 2D electrons transportation layer for Ag microplates. The Ag/ZnO heterostructure was fabricated by utilizing the rivalrous polyol reduction method and aqueous solution method. The experimental results showed that the edge length of single crystalline Ag microplates can reach up to 5 μm, and the Ag microplates are highly oriented with {111} facets as the basal planes. Arrays of single crystalline ZnO NWs were vertically assembled along <0001> direction attaching on the {111} facets of Ag microplates. It was confirmed by scanning electron microscope (SEM), transmittance electron microscope (TEM) and X–ray photoemission spectrum (XPS), revealing the direct contact and the charge transfer between Ag microplates and ZnO nanowires. Meanwhile, contacts of Ag/ZnO heterostructure form the charge separation, so enhance the photocatalytic activity by using the representative target pollutant–Methyl blue (MB). It shows the positive results of the heterostructure enhance the activities of MB photodegradation at the pseudo first order kinetic constant of 6.60×10-3 min-1 by means of employing micrograms of photocatalysts.