Preparation and photocatalytic activity of TiO2 nanocomposites coated with monolayer-protected gold clusters

Piyadarsha Amaratunga, Myeongsoon Lee, Junhyung Kim, Dongil Lee

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

We report the preparation and photocatalytic activity of TiO2 nanocomposites modified with monolayer-protected gold clusters (MPCs). Highly monodisperse tiopronin-coated MPCs with core diameters of 2.2 ± 0.2 nm were pre-prepared and then anchored onto a TiO2 surface using the bifunctional tiopronin linker. In this method, the gold core size was preserved after calcination at 260 °C as well as the anchoring process, and the gold loading on TiO2 could be precisely controlled by the experimental condition. The photocatalytic degradation of Rhodamine 590 (Rh-590) was carried out with thus prepared MPC-TiO2 composites. Mechanistic study of the photocatalytic reactions revealed that the degradation of Rh-590 occurs via the oxidative pathway by photogenerated holes. The photocatalytic activity of the MPC-TiO2 composites was found to increase significantly upon calcination at 260 °C, whereas the size of gold particles remained at their initial size. The photocatalytic activity of the composites, however, drastically decreased when the composites were calcined at 400 °C. X-ray photoelectron spectroscopy analysis of the calcined composites was conducted to understand the vastly different calcination results. A significant amount of oxidized sulfur remained in the composites after calcination at 400 °C, which appears to be responsible for the drastic decrease in the photocatalytic activity.

Original languageEnglish
Pages (from-to)1001-1009
Number of pages9
JournalCanadian Journal of Chemistry
Volume89
Issue number8
DOIs
Publication statusPublished - 2011 Aug

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Organic Chemistry

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