Photoelectrochemical Characterisation of Nanostructured NiTiO3 Thin Film Electrodes

  • Mr Kenrick Anderson, CSIRO Energy Technology, Australia
  • Christopher Fell, CSIRO Energy Technology, Australia
  • Prof Sten-Eric Lindquist, CSIRO Energy Technology, Australia

    • The yellow substance nickel titanate (NiTiO3) has a bandgap around 2.2eV, making it a suitable material for photoelectrochemical (PEC) harvesting of sunlight as a future energy source. Although the PEC properties of this material were robustly investigated in the early 1980s [1, 2], such studies used flat solid films with often undefined crystallinity and porosity. The recent development of simple techniques to produce well-defined nanoporous thin film electrodes has created the opportunity to reinvestigate the nickel titanate system. Re-examining the theoretical treatment is also interesting, because the early work was based on the classical Schottky barrier junction model, which we now know is inappropriate for nanoporous materials. In this work we will examine the structure and morphology of nanostructured NiTiO3 thin films using X-ray diffraction and electron spectroscopy, and use the photocurrent action spectrum as a tool to verify the zone of efficient charge separation. The results will be explained in light of more recent findings on charge transport mechanisms in porous electrodes [3-5].

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