Visible-Light Photoactivity of Bi-pyrochlores with High Fe Contents

Authors

  • Matjaž Valant Materials Research Laboratory, University of Nova Gorica, 5000, Nova Gorica, Slovenia
  • Metka Benčina Materials Research Laboratory, University of Nova Gorica, 5000, Nova Gorica, Slovenia
  • Mattia Fanetti Materials Research Laboratory, University of Nova Gorica, 5000, Nova Gorica, Slovenia

Keywords:

Photoactivity, Bi-pyrochlores, Fe-content

Abstract

Three Bi-pyrochlores with different Fe contents  (Bi2Ti2O7, Bi1.65Nb1.12Fe1.16O7 and  Bi1.9Te0.58Fe1.52O6.87)  were synthesized in the form of nanopowders with similar morphological characteristics. All three nanopowders show an intensive visible-light photocatalytic activity. The analysis of their band gap and absorption characteristics has shown a strong correlation with the Fe-content indicating that a significant band gap reduction can be obtained by Fe incorporation. The photocatalytic activity has not followed this trend. The initial increase in the Fe-content has resulted in a significant enhancement of the photoactivity while with the further increase the photoactivity has slowly decreased. The reason for this behaviour has been proposed to be in an opposing influence of the increased exciton density and recombination rate.

Downloads

Published

04.09.2014

Issue

Section

Materials science