Ag sensitized TiO2 and NiFe2O4 three-component nanoheterostructures: synthesis, electronic structure and strongly enhanced visible light photocatalytic activity

A. Šutka, T.
Käämbre, R. Pärna, N. Doebelin, M. Vanags, K. Smits and V. Kisand

This study reports on the synthesis and characterisation of two- and three-component visible light active photocatalytic
nanoparticle heterostructures, based on TiO2 and NiFe2O4 and sensitized with Ag. We observe that Ag content as small as
1 at.% in the TiO2/NiFe2O4 heterostructure increases by more than an order of magnitude the rate constant for the visible
light photocatalytic process. We rationalise this in terms of the measured structure and electronic structure data of the
binary and ternary combinations of the component materials and focus on details, which show that an optimised
deposition sequence is vital for attaining the high values of photocatalytic efficiency, because the charge transfer across
the interfaces appears to be sensitive to where the Ag is loaded in the heterostructure. The overall higher visible light
photocatalytic activity of the TiO2/Ag/NiFe2O4 heterostructure was observed and is attributed to enhanced charge carrier
separation efficiency and migration via vectorial electron transfer.

RSC Advances., 2016,

DOI: 10.1039/C6RA00728G

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Photocatalytic Properties of TiO2 and ZnO Nanopowders

L. Grigorjeva, J. Rikveilis, J. Grabis, Dz. Jankovica,
C. Monty, D. Millers, K. Smits

Photocatalytic activity of TiO2 and ZnO nanopowders is studied
depending on the morphology, grain sizes and method of synthesizing.
Photocatalysis of the prepared powders was evaluated by degradation of the
methylene blue aqueous solution. Absorbance spectra (190–100 nm) were
measured during exposure of the solution to UV light. The relationships
between the photocatalytic activity and the particle size, crystal polymorph
phases and grain morphology were analyzed. The photocatalytic activity of
prepared TiO2 nanopowders has been found to depend of the anatase-to-rutile
phase ratio. Comparison is given for the photocatalytic activity of ZnO
nanopowders prepared by sol-gel and solar physical vapour deposition
(SPVD) methods

Latvian Journal of Physics and Technical Sciences 2013, N 4

DOI: 10.2478/lpts-2013-0025

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