Impact of aggregate size and structure on the photocatalytic properties of TiO2 and ZnO nanoparticles.

Journal Article (Journal Article)

Aggregation of photocatalytic semiconductors was determined to reduce the generation of free hydroxyl radicals in aqueous suspensions in a fashion dependent on aggregate size and structure. Static light scattering measurements were used to follow temporal changes in the fractal dimension of aggregating TiO(2) and ZnO nanoparticles. At length scales comparable to nanoparticle size, the structure of aggregated TiO(2) nanoparticles was independent of particle stability and the associated aggregation rate, consistent with the fused nature of TiO(2) primary particles in the initial suspension. In contrast, ZnO aggregates were characterized by smaller fractal dimensions when ionic strength, and the resulting aggregation rate, were increased. The photocatalytic activity of ZnO and TiO(2) in generating free hydroxyl radicals varied with aggregate structure and size, consistent with theory that predicts reduced reactivity as aggregates become larger and more dense.

Full Text

Duke Authors

Cited Authors

  • Jassby, D; Farner Budarz, J; Wiesner, M

Published Date

  • July 2012

Published In

Volume / Issue

  • 46 / 13

Start / End Page

  • 6934 - 6941

PubMed ID

  • 22225505

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/es202009h


  • eng