TY - JOUR
T1 - Synthesis and characterization of Al2O3 nanoparticles by flame spray pyrolysis (FSP)
T2 - Role of Fe ions in the precursor
AU - Hafshejani, Laleh Divband
AU - Tangsir, Sareh
AU - Koponen, Hanna
AU - Riikonen, Joakim
AU - Karhunen, Tommi
AU - Tapper, Unto
AU - Lehto, Vesa-Pekka
AU - Moazed, Hadi
AU - Naseri, Abd Ali
AU - Hooshmand, Abdolrahim
AU - Jokiniemi, Jorma
AU - Bhatnagar, Amit
AU - Lähde, Anna
PY - 2016
Y1 - 2016
N2 - Iron doped aluminium oxide nanoparticles are of interest
for number of applications (e.g. water treatment,
catalytic conversion of exhaust gases) due to their high
surface area, hardness, catalytic and magnetic
properties. In the present study, flame spray pyrolysis
(FSP) was employed for the synthesis of Fe/Al2O3
nanoparticles. Precursor solutions of aluminium
acetylacetonate (0.2 mol·L-1) and ferrocene (0 to 0.2
mol·L-1) in toluene were used to synthesise pure and iron
(Fe) doped Al2O3. The particle composition and morphology
were studied and effect of iron concentration was
analysed. It was found that in the absence of the iron
precursor, FSP produced a mixture of two Al2O3
polymorphs: ?-Al2O3 and ?-Al2O3. The addition of
ferrocene as an iron precursor was found to suppress
formation of ?-Al2O3. At an iron molar concentration of
0.2 mol·L-1 mainly hercynite, FeAl2O4, was observed.
Furthermore, increasing the iron concentration caused a
linear shift of the X-ray diffraction peaks from
positions corresponding to ?-Al2O3 to those of FeAl2O4.
This indicates the formation of a solid solution
(FexAl2O3 + x) at intermediated concentrations. It was
also found that the primary particle size, which was
below 10 nm, did not significantly change with the
increased iron concentration and was comparable to the
mean crystallite size indicating that size of these
single crystalline primaries is determined by the
synthesis process rather than the chemistry of the
product. However, the hydrodynamic size was around 180 nm
indicating that the particles are agglomerates in the
water suspension. Additionally, zeta potential of the
nanoparticles was found to decrease slightly with
increasing iron content, though in all cases it was above
50 mV. Finally, the potential of synthesized
nanoparticles was examined for the removal of fluoride
because fluoride causes harmful health effects to human
health at elevated concentrations. The results of
fluoride removal using synthesized nanoparticles produced
in this study showed that the highest fluoride removal
efficiency was observed for the sample having no iron
content.
AB - Iron doped aluminium oxide nanoparticles are of interest
for number of applications (e.g. water treatment,
catalytic conversion of exhaust gases) due to their high
surface area, hardness, catalytic and magnetic
properties. In the present study, flame spray pyrolysis
(FSP) was employed for the synthesis of Fe/Al2O3
nanoparticles. Precursor solutions of aluminium
acetylacetonate (0.2 mol·L-1) and ferrocene (0 to 0.2
mol·L-1) in toluene were used to synthesise pure and iron
(Fe) doped Al2O3. The particle composition and morphology
were studied and effect of iron concentration was
analysed. It was found that in the absence of the iron
precursor, FSP produced a mixture of two Al2O3
polymorphs: ?-Al2O3 and ?-Al2O3. The addition of
ferrocene as an iron precursor was found to suppress
formation of ?-Al2O3. At an iron molar concentration of
0.2 mol·L-1 mainly hercynite, FeAl2O4, was observed.
Furthermore, increasing the iron concentration caused a
linear shift of the X-ray diffraction peaks from
positions corresponding to ?-Al2O3 to those of FeAl2O4.
This indicates the formation of a solid solution
(FexAl2O3 + x) at intermediated concentrations. It was
also found that the primary particle size, which was
below 10 nm, did not significantly change with the
increased iron concentration and was comparable to the
mean crystallite size indicating that size of these
single crystalline primaries is determined by the
synthesis process rather than the chemistry of the
product. However, the hydrodynamic size was around 180 nm
indicating that the particles are agglomerates in the
water suspension. Additionally, zeta potential of the
nanoparticles was found to decrease slightly with
increasing iron content, though in all cases it was above
50 mV. Finally, the potential of synthesized
nanoparticles was examined for the removal of fluoride
because fluoride causes harmful health effects to human
health at elevated concentrations. The results of
fluoride removal using synthesized nanoparticles produced
in this study showed that the highest fluoride removal
efficiency was observed for the sample having no iron
content.
KW - FeAl2O4
KW - Flame spray pyrolysis (FSP)
KW - Fluoride removal
KW - Lattice parameter
U2 - 10.1016/j.powtec.2016.05.003
DO - 10.1016/j.powtec.2016.05.003
M3 - Article
VL - 298
SP - 42
EP - 49
JO - Powder Technology
JF - Powder Technology
SN - 0032-5910
ER -