Ag Nanoparticle Decorated Nanoporous ZnO Microrods and Their Enhanced Photocatalytic Activities

详细信息    查看全文

• 作者：Quan Deng ; Xiaowei Duan ; Dickon H. L. Ng ; Haibin Tang ; Yong Yang ; Mingguang Kong ; Zhikun Wu ; Weiping Cai ; Guozhong Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：November 28, 2012
• 年：2012
• 卷：4
• 期：11
• 页码：6030-6037
• 全文大小：485K
• 年卷期：v.4,no.11(November 28, 2012)
• ISSN：1944-8252

文摘

Nanostructured Ag nanoparticles (Ag-NPs)/nanoporous ZnO micrometer-rods (n-ZnO MRs) have been synthesized by a two-step method. The n-ZnO MRs was initially prepared by solvothermal-assisted heat treatment. The rods had the diameter ranged from 90 to 150 nm and length between 0.5 and 3 渭m. They were found to be porous and were composited of ZnO nanopartiles with size of about 20 nm. In the second stage, Ag-NPs with a diameter of 20鈥?0 nm were anchored onto the surface of the as-prepared n-ZnO MRs by a photoreduction method. The Ag-NPs/n-ZnO MRs were evaluated for their ability to degrade methylene blue (MB) solution under visible to ultraviolet (UV) light irradiation. The rate of degradation of the as-prepared Ag-NPs/n-ZnO MRs was more than twice and nearly 5.6 times faster than that of using bare n-ZnO MRs under the UV and solar light irradiation, respectively. The formation of Schottky barriers in the regions between the Ag-NPs and n-ZnO MRs had improved the charge separation and consequently enhanced the efficiency of the degradation process. Moreover, the as-prepared hybrid structure exhibited high photostability, and 98% of degradation efficiency could be maintained even after being used five times. This endurance was attributed to the retardation of photocorrosion of ZnO as a result of the low concentration of surface defects in the as-prepared n-ZnO MRs. It also minimized the surface defects of the as-prepared n-ZnO MRs and consequently further inhibited the photocorrosion of ZnO when the deposited Ag-NPs were much more inclined to combine with the chemisorbed oxygen.

Keywords:

Ag nanoparticles; ZnO micrometer-rods; solvothermal method; photoreduction; photocatalytic activities