Journal of Applied Electrochemistry

, Volume 35, Issue 7–8, pp 683–692 | Cite as

The photoelectrocatalytic oxidation of aqueous nitrophenol using a novel reactor

  • P. A. ChristensenEmail author
  • T. A. Egerton
  • S. A. M. Kosa
  • J. R. Tinlin
  • K. Scott


This paper reports the oxidation of aqueous 4-nitrophenol solutions in a photo-electrochemical bubble column reactor (BCR) in which mass transfer has been shown not to be rate limiting. The work represents the first steps in the scale-up of active photoanodes and efficient reactors for the disinfection and detoxification of water.

The preparation, optimization and application of two types of electrode are described and the results are compared with those for a TiO2 electrode supplied by Ineos Chlor. Photocurrents measured in tap water and in aqueous methanol were used for the initial characterization of the electrodes. The methanol was employed for diagnostic purposes only, as discussed below; methanol can react either by direct hole transfer or by hydroxyl radical recombination, but the balance of these reactions depends upon the nature of the electrode surface. The most active thermal electrodes were fabricated by heating titanium metal in air at 750 °C for 10 min, whilst the most active sol–gel electrodes were heated at 600 °C for 10 min.

Three of the central achievements of the work were to: (1) show that it is possible to design and fabricate photoelectrochemical reactors capable of effecting the mineralization of strongly absorbing organics; (2) confirm that the photocatalytic decomposition of 4-NP in reactors with a 4 dm3 capacity can be increased by the application of a small positive potential and (3) that the application of such a potential significantly enhances the mineralization of 4-NP.

For the mineralization of 0.25 mM nitrophenol solutions the reactivity sequence is:

Photoelectrocatalytic > Photocatalytic > Photochemical > Electrochemical.

However, even at 3 V applied potential, charge recombination is not eliminated. The order of electrode activity was:

Ineos > Sol Gel > Thermal.

Differences between the activities of different electrodes were attributed to changes in the structure and morphology of the TiO2. It is noteworthy that although, for nitrophenol oxidation, the thermal electrodes were the least active, for photoelectrocatalytic disinfection in the same type of reactor, thermal electrodes were the most active.


bubble column reactor electric field enhancement nitrophenol photoelectrocatalytic sol–gel TiO2 electrode thermal TiO2 electrode 


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  1. 1.
    Mills, A., Le Hunte, S. 1997J. Photochem. Photobiol. A1081Google Scholar
  2. 2.
    P.A. Christensen and G.M. Walker Opportunities for the UK in Solar Detoxification, ETSU s/P4/00249/REP 1996.Google Scholar
  3. 3.
    Tryk, D.A., Fujishima, A., Honda, K. 2000Electrochim. Acta452363CrossRefGoogle Scholar
  4. 4.
    Goodeve, C.F., Kitchener, J.A. 1938Trans. Faraday Soc34902Google Scholar
  5. 5.
    Carey, J.H., Lawrence, J., Tosine, H.M. 1976Bull. Environ. Contam. Toxicol16697CrossRefGoogle Scholar
  6. 6.
    A.L. Pruden and D.F. Ollis, J. Catal. 82 (1983) 404; C.Y. Hsia, C.Y. Lee and D.F. Ollis, J. Catal. 82 (1983) 418.Google Scholar
  7. 7.
    Matsunaga, T., Tomada, R., Nakajima, T., Wake, H. 1985Microbiol. Lett29211Google Scholar
  8. 8.
    Sun, L., Bolton, J.R. 1996J. Phys. Chem1004127Google Scholar
  9. 9.
    Torimoto, T., Ito, S., Kiwabata, S., Yoneyama, H. 1996Environ. Sci. Technol301275CrossRefGoogle Scholar
  10. 10.
    Choi, W., Ko, J.Y., Park, H., Chung, J.S. 2001Appl. Cat. B Environ31209Google Scholar
  11. 11.
    Wyness, P., Klausner, J.F., Goswami, D.Y. 1994J. Solar. Eng1168Google Scholar
  12. 12.
    Crittenden, J.C., Zhang, Y., Hand, D.W. 1996Water Environ. Res68270Google Scholar
  13. 13.
    L.M. Peter, in R.G. Compton and A. Hamnett (Eds), Comprehensive Chemical Kinetics, Vol. 29 (Elsevier, Amsterdam, 1989), p. 353 and references cited therein.Google Scholar
  14. 14.
    A. Hamnett, in R.G. Compton (Ed.), Comprehensive Chemical Kinetics, Vol. 27 (Elsevier, Amsterdam, 1987), p. 61.Google Scholar
  15. 15.
    Gautron, J., Lemasson, P., Marucco, J.F. 1980Far. Disc. Chem. Soc7087Google Scholar
  16. 16.
    Gerischer, H. 1993Electrochim. Acta383CrossRefGoogle Scholar
  17. 17.
    Butterfield, I.M., Christensen, P.A., Hamnett, A., Shaw, K.E., Walker, G.M., Walker, S.A., Howarth, C.R. 1997J. Appl. Electrochem27385CrossRefGoogle Scholar
  18. 18.
    Harper, J.C., Christensen, P.A., Egerton, T.A., Curtis, T.P., Gunlazuardi, J. 2001J. Appl. Electrochem31623Google Scholar
  19. 19.
    Christensen, P.A., Curtis, T.P., Place, B., Walker, G.M. 2002Water Res362410Google Scholar
  20. 20.
    K.A. Grey, P. Kamat, U. Stafford and M. Dieckmann, Abstr. Papers Am. Chem. Soc. 203 (1992) 307-ENVR.Google Scholar
  21. 21.
    O’Regan, B., Moser, J., Anderson, M., Gratzel, M. 1990J. Phys. Chem948720Google Scholar
  22. 22.
    B.D. Cullity, Elements of X-ray Diffraction (Addison-Wesley, 1959).Google Scholar
  23. 23.
    Harper, J.C., Christensen, P.A., Egerton, T.A., Scott, K. 2001Appl. Electrochem31267Google Scholar
  24. 24.
    T.A. Egerton and P.A. Christensen, in S. Parsons (Ed.), ‘Advanced Oxidation Processes for Water and Wastewater Treatment’ (IWA Publishing, London, 2004), pp. 167–184Google Scholar
  25. 25.
    Douglas, D.L., Van Landuyt, J. 1966Acta Metal14491Google Scholar
  26. 26.
    Jiang, D., Zhao, H., Zhang, S., John, R. 2003J. Phys. Chem10712774Google Scholar
  27. 27.
    Vinodgopal, K., Stafford, U., Gray, K.A., Kamat, P.V. 1994J. Phys. Chem986797CrossRefGoogle Scholar
  28. 28.
    Semenikhin, O.A., Kazarinov, V.E., Jiang, L., Hashimoto, K., Fujishima, A. 1999Langmuir153731CrossRefGoogle Scholar
  29. 29.
    Wahl, A., Ulmann, M., Carroy, A., Jermann, B., Dolata, M., Kedzierzawski, P., Chatelain, C., Monnier, A., Augustynski, J. 1995J. Electroanal. Chem39641CrossRefGoogle Scholar
  30. 30.
    Park, H., Choi, W. 2004J. Phys. Chem. B1084086Google Scholar
  31. 31.
    Zhang, H.Z., Banfield, J.F. 1998J. Mater. Chem82073Google Scholar
  32. 32.
    Salinaro, E.A., Serpone, N. 2000J. Phys. Chem10411202Google Scholar
  33. 33.
    Egerton, T.A., King, C.J. 1979J. Oil Col. Chem. Assoc26386Google Scholar
  34. 34.
    Pelizzetti, E., Maurino, V., Minero, C., Carlin, V., Pramauro, E., Zerbinati, O., Tosato, M.L. 1990Environ. Sci. Technol241559CrossRefGoogle Scholar
  35. 35.
    J.R. Tinlin, Ph. D. Thesis, Newcastle upon Tyne UK (2003).Google Scholar
  36. 36.
    Christensen, P.A., Curtis, T.P., Egerton, T.A., Kosa, S.A.M., Tinlin, J.R. 2003Appl. Cat. B Environ41371Google Scholar

Copyright information

© Springer 2005

Authors and Affiliations

  • P. A. Christensen
    • 1
    Email author
  • T. A. Egerton
    • 1
  • S. A. M. Kosa
    • 1
  • J. R. Tinlin
    • 1
  • K. Scott
    • 1
  1. 1.School of Chemical Engineering and Advanced Materials, Merz CourtThe UniversityNewcastle upon TyneUK

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