UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Dynamics of photogenerated charges in the phosphate modified TiO and the enhanced activity for photoelectrochemical water splitting
  • Publication Type:
    Journal article
  • Authors:
    Jing L, Durrant JR, Zhou J, Liu D, Fu H, Tang J
  • Publication date:
    04/2012
  • Pagination:
    6552, 6558
  • Journal:
    Energy and Environmental Science
  • Volume:
    5
  • Issue:
    4
  • Print ISSN:
    1754-5692
Abstract
Phosphate modified nanocrystalline TiO (nc-TiO ) films were prepared by a doctor blade method, followed by post-treatment with monometallic sodium orthophosphate solution. The dynamic processes of the photogenerated charges from the resulting nc-TiO films were thoroughly investigated by means of transient absorption spectroscopy (TAS). It is shown that photogenerated holes in the un-modified TiO film exhibit the same dynamic decay process as its photogenerated electrons, in oxygen-free water of pH 7. However, photogenerated holes in the phosphate modified film display a slightly faster dynamic decay process than its photogenerated electrons, and photogenerated charges of the modified film have a much longer lifetime than those of the un-modified film. These differences are attributed to the surface-carried negative charges of nc-TiO resulting from the phosphate groups (-Ti-O-P-O ). Interestingly, the photoelectrochemical (PEC) experiments show that modification with an appropriate amount of phosphate could improve the photocurrent density of the nc-TiO film electrode by about 2 times, at a voltage of 0 V in the neutral electrolyte. Based on the TAS and PEC measurements of un-modified and phosphate modified nc-TiO films, with different conditions, it is suggested that the prolonged lifetime of photogenerated charges can be attributed to the negative electrostatic field formed in the surface layers. It is also responsible for the increase in activity for PEC water splitting and for the reported photocatalytic degradation of pollutants. The suggested mechanism would be applicable to other oxide semiconductor photocatalysts and to modification with other inorganic anions. This journal is © 2012 The Royal Society of Chemistry.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
Dept of Chemical Engineering
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by