Characterization of Sputtered HfO2−x–TiO2−x Nanocolumn Arrays and Their Application in Photocatalysis

Hao Che Feng, Kao Shuo Chang

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2 Citations (Scopus)


The physical and chemical properties of sputtered HfO2−x–TiO2−x nanocolumn arrays and the photocatalytic action of high-ε (HfO2) nanocolumns for decomposition of methylene blue have been studied. Fabrication of HfO2−x–TiO2−x nanocolumn array composites by reactive sputtering without further treatment was comprehensively investigated. Well-isolated HfO2−x nanocolumns with maximum separation of approximately 500 nm and excellent orientation normal to the substrate were obtained. The coupling between HfO2−x and TiO2−x was found to be crucial for enhanced photocatalytic action; the optimal coupling was identified for HfO2−x–TiO2−x nanocolumn composites with four pairs of alternating layers, which showed better performance (by approximately 25%) under 30 W of ultraviolet (UV) irradiation, compared with TiO2−x thin films. The synergistic photocatalytic effect was predominantly attributed to defect-induced electron migration along the HfO2−x nanocolumn structure. In addition, the corresponding photoluminescence spectra and energy band diagram for the HfO2−x–TiO2−x system were used to complement the photocatalytic results.

Original languageEnglish
Pages (from-to)4532-4538
Number of pages7
JournalJournal of Electronic Materials
Issue number7
Publication statusPublished - 2017 Jul 1

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry


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