Nanostructured Ti-doped hematite (α-Fe2O3) photoanodes for efficient photoelectrochemical water oxidation

Myeong Hwan Lee, Jong Hoon Park, Hyun Soo Han, Hee Jo Song, In Sun Cho, Jun Hong Noh, Kug Sun Hong

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

We present a form of hematite (α-Fe2O3) nanostructured architecture suitable for photoelectrochemical water oxidation that is easily synthesized by a pulsed laser deposition (PLD) method. The architecture is a column-like porous nanostructure consisting of nanoparticles 30-50 nm in size with open channels of pores between the columns. This nanostructured film is generated by controlling the kinetic energy of the ablated species during the pulsed laser deposition process. In a comparison with the nanostructured film, hematite thin film was also synthesized by PLD. All of the developed films were successfully doped with 1.0 at% of titanium. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and UV-visible spectroscopy were used to characterize the films. To fabricate the photoelectrochemical (PEC) cell, Ti-doped hematite films were used as the working electrode, Ag/AgCl as the reference electrode, platinum wire as the counter electrode and an aqueous solution of 1 M NaOH as the electrolyte. The photovoltaic characteristics of all cells were investigated under AM 1.5G sunlight illumination of 100 mW/cm2. The photocurrent density was enhanced by approximately 220% using nanostructured film at 0.7 V versus Ag/AgCl compared to hematite thin film, and the highest photocurrent density of 2.1 mA/cm2 at 0.7 V/Ag/AgCl was obtained from the 1.0 at% Ti-doped hematite nanostructured film. The enhanced photocurrent density is attributed to its effective charge collection due to its unique column-like architecture with a large surface area.

Original languageEnglish
Pages (from-to)17501-17507
Number of pages7
JournalInternational Journal of Hydrogen Energy
Volume39
Issue number30
DOIs
Publication statusPublished - 2014 Oct 13
Externally publishedYes

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Keywords

  • Column-like
  • Hematite
  • Nanostructure
  • Photoelectrochemical
  • Pulsed laser deposition (PLD)

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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