Abstracts Book - IMRC 2018

• SF5-P013
PHOTOCATALYTIC ACTIVITY OF Fe3O4@Gd- BiFeO3 CORE-SHELL
NANOSTRUCTURES FOR MB DYE DEGRADATION UNDER VISIBLE-
LIGHT IRRADIATION
Carlos Ostos 1 , Giovanny Esteban Gonzalez Urrego 1 , Sara Isabel Carmona 1 , Jose Daniel Velez
Ruiz 1 , Lina Marcela Castro 1
1 Universidad de Antioquía, ANT, Colombia.
Nowadays, the field of heterogeneous photocatalysis based on the use of
semiconductor metal oxides represent a promising alternative for energy
generation and environmental remediation processes. TiO 2 has been widely
used due to its activity under UV and part of visible solar spectra; but others
semiconductors, like BiFeO 3 (BFO), represent a good alternative to take
advantage of solar irradiation because its narrow band-gap. In this work, we
synthesized a family of multifunctional semiconductor oxides based on BiFeO 3
(BFO). In this process, two kinds of nanoparticles Bi 1-x Gd x FeO 3 (Gd-BFO, 0 ≤ x ≤
0.5) and core-shell Fe 3 O 4 @ Bi 1-x Gd x FeO 3 (IO@Gd-BFO, 0 ≤ x ≤ 0.5) were fabricated
through an alternative route of soft chemistry. To evaluate the microstructural
and chemical surface characteristics of the solids the XRD, XPS, SEM and TEM
techniques were employed. The results showed a crystalline structure transition
from a rhombohedral (R3c) to orthorhombic phase (Pnma) as the content of Gd
is increased. The samples showed spherical agglomerated nanoparticles
morphology and the presence of Gd(III) into the BFO samples was confirmed.
Surface chemistry analyses demonstrated the chemical ambient of each one of
the ions involved, even at small percentages of Gd substitution. The
photocatalytic activity was evaluated for the degradation of methylene blue (MB)
dye in an aqueous diluted solution (10 ppm) under artificial solar-light
irradiation. The BFO activity indicated an 84.5% of the MB degradation, and the
performance was improved for Gd-BFO samples, being the best performance
for the 1%Gd-BFO sample achieving a 98.4% after 120 min. In the other hand,
IO@Gd-BFO samples were also more active than that of both BFO and IO@BFO
systems, particularly, the IO@5%Gd-BFO sample reached got a 96.6% after 180
min of irradiation using a 100W Xenon lamp to simulate a visible-light spectrum.
Acknowledgment:
The authors would like to thank to the project 111565843400 of Colciencias for
the financial support.