Shape-dependent charge transfers in crystalline ZnO photocatalysts: Rods versus plates

Hye Won Jeong, Seung Yo Choi, Seong Hui Hong, Sang Kyoo Lim, Dong Suk Han, Ahmed Abdel-Wahab, Hyunwoong Park

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

ZnO particles with rod and plate configurations were synthesized using a solvothermal method using zinc acetate and zinc chloride, respectively. The surface of the as-synthesized ZnO rods and plates were characterized using various analysis tools (XRD, XPS, photoluminescence, FE-SEM, HR-TEM, BET, and UV-vis) and their photocatalytic activities were examined for six different redox reactions. The surface areas and bandgaps of the two ZnO samples were nearly identical; however, XPS and photoluminescence (PL) studies showed that the rods and the plates have relatively pronounced oxygen vacancy and oxygen interstitial contributions, respectively. ZnO rods were found to be active for the decomposition of methylene blue and phenol, the production of OH radicals, and the generation of photocurrents, all of which are associated with single-electron transfer reactions. On the other hand, ZnO plates were more effective for the production of molecular hydrogen and hydrogen peroxide, both of which are initiated by two-electron transfer reactions. These single versus multiple charge transfers are discussed with regard to the roles of oxygen vacancies and oxygen interstitials, which are located near the conduction and the valence bands, respectively.

Original languageEnglish
Pages (from-to)21331-21338
Number of pages8
JournalJournal of Physical Chemistry C
Volume118
Issue number37
DOIs
Publication statusPublished - 18 Sep 2014

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Energy(all)

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