Ag nanoparticle decorated nanoporous ZnO microrods and their enhanced photocatalytic activities

ACS Appl Mater Interfaces. 2012 Nov;4(11):6030-7. doi: 10.1021/am301682g. Epub 2012 Nov 1.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Electric Power Supplies*
  • Equipment Design
  • Equipment Failure Analysis
  • Light
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / radiation effects
  • Porosity
  • Silver / chemistry*
  • Silver / radiation effects
  • Solar Energy*
  • Zinc Oxide / chemistry*

Substances

  • Silver
  • Zinc Oxide