title: Ag nanoparticle decorated nanoporous ZnO microrods and their enhanced photocatalytic activities.
abstract: 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 μm. 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 20-50 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.
authors.affiliation: Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031, P.R. China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Deng
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Duan
authors.forename: Dickon H L
authors.initials: DH
authors.lastname: Ng
authors.forename: Haibin
authors.initials: H
authors.lastname: Tang
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.forename: Mingguang
authors.initials: M
authors.lastname: Kong
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Wu
authors.forename: Weiping
authors.initials: W
authors.lastname: Cai
authors.forename: Guozhong
authors.initials: G
authors.lastname: Wang
mesh_terms: D002384:Catalysis; D011211:Electric Power Supplies; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D016062:Porosity; D012834:Silver / Q000737:chemistry* / Q000528:radiation effects; D012993:Solar Energy; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D012834:Silver; D015034:Zinc Oxide