Microstructure promoted photosensitization activity of dye-titania/titanium composites

Yibing Xie, Li Min Zhou, Haitao Huang, Jian Lu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

Well-constructed titania reactive layer/titanium metal-matrix composites were fabricated for photosensitization substrate application by a controlled electrochemical anodization process. A low-voltage anodization at 20 V produced titania nanotube array with 60-70 nm diameter and 540 nm height, while a high-voltage anodization at 180 V resulted in titania multiporous film with 170-260 nm pore size and 4 μm thickness. Two types of dye-titania/titanium composite electrodes were also prepared through a surface adsorption modification by orange G dye. The surface morphologies and interfacial electric properties of heterogeneous materials were examined by microstructure characterization and electrochemical impedance spectroscopy analysis. The significant decrease of interfacial charge-transfer resistance from 12,000 Ω for microporous titania to 5100 Ω for nanotubular titania accordingly contributed a much lower electrode impedance and higher polarization current for dye-titania/titanium electrode. Additionally, 4 and 1.5 times magnification of photocurrent density and photovoltage were achieved under a visible light irradiation for nanotubular dye-titania/titanium electrode in comparison with microporous one. A better photosensitization activity could be well obtained by tailoring microstructure from micro-composite to nano-composite. The corresponding photocurrent response was more significant than photovoltage in the photosensitivity evaluation of these composite electrodes.
Original languageEnglish
Pages (from-to)690-696
Number of pages7
JournalComposites Part A: Applied Science and Manufacturing
Volume39
Issue number4
DOIs
Publication statusPublished - 1 Apr 2008

Keywords

  • A. Metal-matrix composites (MMCs)
  • B. Chemical properties
  • B. Microstructure
  • E. Surface treatments

ASJC Scopus subject areas

  • Ceramics and Composites
  • Mechanics of Materials

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