Platinum-like Behavior of Reduced Graphene Oxide as a Cocatalyst on TiO 2 for the Efficient Photocatalytic Oxidation of Arsenite

Gun Hee Moon, Dong Hyo Kim, Hyoung Il Kim, Alok D. Bokare, Wonyong Choi

Research output: Contribution to journalArticle

79 Citations (Scopus)

Abstract

The preoxidation of arsenite [As(III)] to arsenate [As(V)] is usually needed for efficient removal of arsenic from water, and TiO 2 -based photocatalytic oxidation has been investigated as an environmentally benign process for this purpose. The oxidation efficiency can be markedly enhanced when using platinum (Pt) as a cocatalyst, but its expensive material cost hinders its practical application. Herein, we prepared the reduced graphene oxide (rGO) hybridized with TiO 2 as a low-cost alternative to Pt and achieved a highly enhanced activity for the photocatalytic oxidation of As(III), which is comparable to that of Pt/TiO 2 . While either superoxide or hydroxyl radical can be involved as a main oxidant depending on the experimental condition, this study shows that not only superoxide but also hydroxyl radicals (or hole) can be directly involved in As(III) photo-oxidation when rGO is present as a cocatalyst. The photocatalytic activity, charge transfer characteristics, and arsenic oxidation mechanism observed with rGO-loaded TiO 2 are very similar to those of Pt/TiO 2 . The nanocomposite of rGO/TiO 2 that consists of earth-abundant elements only is proposed as a practical environmental photocatalyst for pretreating As(III)-contaminated water.

Original languageEnglish
Pages (from-to)185-190
Number of pages6
JournalEnvironmental Science and Technology Letters
Volume1
Issue number2
DOIs
Publication statusPublished - 2014 Feb 11

All Science Journal Classification (ASJC) codes

  • Environmental Chemistry
  • Ecology
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

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