, Volume 24, Issue 3, pp 861–872 | Cite as

Towards sustainable energy. Photocatalysis of Cr-doped TiO2: 3. Effect of oxygen activity

  • Kazi Akikur Rahman
  • Tadeusz Bak
  • Armand Atanacio
  • Mihail Ionescu
  • Janusz NowotnyEmail author
Original Paper


The present chain of five papers considers the concept of solar-to-chemical energy conversion using TiO2-based semiconductors. The series reports the effect of chromium on the key performance-related properties of polycrystalline TiO2 (rutile), including electronic structure, photocatalytic activity, intrinsic defect disorder, electrochemical coupling and surface vs. bulk properties. The present work reports the effect of oxygen activity in the oxide lattice on photocatalytic activity of pure and Cr-doped TiO2 (0.04 at% Cr). Processing of specimens included annealing at 1273 K in the gas phase of controlled oxygen activity in the range 10−12 Pa < p(O2) < 105 Pa. We show that the increase of oxygen activity results initially in a decrease of photocatalytic activity, minimum around the n-p transition point, and then increase assuming maximum at p(O2) = 105 Pa. The obtained results are considered in terms of a theoretical model that explains the effect of defect disorder on the reactivity of TiO2 with water. The minimum of the photocatalytic activity corresponds to the n-p transition point. The maximum of performance at high p(O2) is determined by increased concentration of titanium vacancies forming surface active sites.


Defect disorder Oxygen activity Reactivity 



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Copyright information

© Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Kazi Akikur Rahman
    • 1
  • Tadeusz Bak
    • 1
  • Armand Atanacio
    • 2
  • Mihail Ionescu
    • 2
  • Janusz Nowotny
    • 1
    Email author
  1. 1.Solar Energy Technologies, School of Computing, Engineering and MathematicsWestern Sydney UniversityPenrithAustralia
  2. 2.Institute of Environmental ResearchAustralian Nuclear Science and Technology OrganisationKirraweeAustralia

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