Bismuth ferrite (BiFeO3) is important multiferroic oxide
material because of the unique magnetic and ferroelectric properties.
Here, we synthesize for the first time highly ordered mesoporous
BiFeO3 semiconductor using tartaric acid-assisted growth
of BiFeO3 compound inside the pores of carbon template.
Powder X-ray diffraction (XRD), transmission electron microscopy (TEM)
and N2 physisorption measurements reveal that the template-free
material possesses three-dimensional hexagonal mesostructure with large
internal BET surface area (141 m2 g-1)
and narrow sized pores (ca. 4 nm). Also, the pore walls comprise
single-phase BiFeO3 nanocrystals according to the
high-resolution TEM, electron diffraction and magnetic experiments.
The mesoporous BiFeO3 shows high activity for the photocatalytic
oxygen evolution reaction (OER) under UV visible light (λ > 380 nm),
affording an average oxygen evolution rate
of 66 μmol h-1 g-1.
We also show that the propensity of photogenerated holes for OER
can be significantly enhanced when 1 wt% Au nanoparticles
are deposited on the BiFeO3 surface.
The Au/BiFeO3 heterostructure exerts excellent OER
activity (586 μmol h-1 g-1)
and long-term cycling stability, raising the possibility
for the design of effective and robust OER photocatalysts.
From: Ioannis Papadas, Joseph A. Christodoulides, George Kioseoglou and Gerasimos S. Armatas,
“High Surface Area Ordered
Mesoporous BiFeO3 Semiconductor with Efficient Water Oxidation
Activity”
J. Mater. Chem. A,
3, 1587-1593 (2015).