Abstract: The principle of melt-phase separation process for preparation of nanoparticle TiO2 is based on
the adjustment of glass phase-separation structure. TiO2 grain size can be controlled by changing heat
treatment temperature. The sample was composed of Na2O-B2O3-SiO2-TiO2 glass system (melted at
1573K). A photocatalytic nanoparticle TiO2 which was loaded on porous glass can be obtained by heat
treatment of glass system at various temperatures and then acid washing. The results have shown that the
glass phase-separation structure size matches crystallization rate and an optimal photodegradation
property of TiO2 is achieved. It was found that the suitable heat treatment condition was at 848K for 12h,
although its performance slightly changes with the composition variations.
Abstract: Nanometer CeO2 with the mean size of 15 nm is prepared by sol-gel method, and the CO
catalytic oxidation activity of Pd-Cu catalysts with three kinds of CeO2 supports was studied. The results
show that nanometer CeO2 supported Pd-Cu catalyst gives highest activity for CO oxidation. It can
maintain CO complete conversion at about 40°C.
Abstract: The catalysts based on V/K/Ca and V/Ks/Ce systems for diesel soot catalytic oxidation were
synthesized onto the porous alumina substrates. Both catalyst systems showed a good catalytic oxidation
activity. The V/K/Ca system exhibited the lowest oxidation onset temperature (OOT) of about 359oC with
a composition of V/K/Ca =1:1:0.1 where the V and Ca and/or K elements could form a kind of amorphous
phase that determined the catalytic activity. The V/Ks/Ce system displayed the lowest OOT of about
350oC with a composition of V/Ks/Ce = 1:2:0.1 where the K2SO4 and K5V2O3(SO4)4 phases could
contribute most to the catalytic activity.
Abstract: A sol-gel process was used to synthesize nanosized Ca-Zn ferrite powders. DTA-TG, XRD and
SEM techniques are employed to investigate the thermal decomposition of the dry gel, phase composition
and microstructure of nanosized ferrite particles. The results revealed that the Ca0.4Zn0.6Fe2O4 phase
appeared while calcined the gel powders at 300 °C for 2 hrs, and the Ca0.4Zn0.6Fe2O4 crystalline can be
formed completely at 400 °C. Hysteresis loop indicated that the nanocrystallites size has great influence
on the magnetic properties, which leads to the increase of the specific saturation magnetization and the
decrease in coercivity of the samples with increasing the particle size.
Abstract: Rare earth Yb-doped bismuth titanate Bi4-xYbxTi3O12 (BYT) nanocrystalline powders were
obtained by a modified sol-gel method. TG-DTA, FI-IR and XRD were used to determine the lowest heat
treatment temperature. Phase changes in the formation of BYT crystalline powders were discussed by
XRD. The effect of Yb3+ cation substitution for Bi3+ cation on the microstructure of BYT was also
developed with XRD. The grain size of BYT nanopowders is about 40 nm determined by TEM.
Abstract: Nanosized Ce0.8Gd0.05Y0.15O1.9 powders were synthesized using glycine nitrate process for use
as the electrolyte of intermediate temperature solid oxide fuel cells. The powders were characterized by
simultaneous thermogravimetry analysis (TGA) and differential thermal analysis (DTA), X-ray powder
diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
The XRD pattern indicated that the powders exhibited a single phase with cubic fluorite structure. The
TEM studies showed that the calcined powders exhibited an almost spherical morphology and the mean
size of the particles was 30nm, which is in agreement with the calculated result of XRD.
Abstract: Nano-scaled particle of anatase phase titanium oxide was obtained from the conversion of
ammonium oxotrifluorotitanate by thermal treatment in oxygen. The crystal of ammonium
oxofluorotitanate was grown on glass at 40oC with an aqueous solution of ammonium hexafluorotitanate
and boric acid. The titanium oxide was obtained from the conversion of ammonium oxotrifluorotitanate
by thermal treatment in oxygen. The size of nano-scaled anatase titanium oxide increases with the
temperature of thermal treatment, and the size distribution is from 10 to 30 nm corresponding to the
thermal temperature from 300 to 1000oC. The photocatalytic activity of the nano-scaled titanium oxide
was demonstrated by the photo-deposition of copper in the solution of copper nitrate and sodium oxalate.
The photocatalytic activity for the sample treated thermally at 800 oC is 1.3 times higher than that of
Abstract: The effect of ultrasonic treatment under low frequency and power condition on the surface
adsorption state and photocatalysis activity of nanosized TiO2 photocatalyst was studied. Results obtained
from UV-Vis absorption spectra revealed that obvious differences of adsorption state on TiO2 powder
surface were found after ultrasonic treatment, which agreed with the DTA-TG results that the thermal
peaks varied with increasing ultrasonic treatment time. Furthermore, the photocatalysis activity for
methyl-orange solution under visible light irradiation (≥450 nm) varied in a similar way with increasing
ultrasonic treatment time. Present study revealed that the ultrasonic treatment was an effective way to
study the relation between the surface adsorption state and photocatalysis activity of present nanosize
Abstract: Precursor of nanosized TiO2 was prepared by alkoxide hydrolysis method. It was dried by
common drying, far infrared drying, vacuum drying and supercritical drying before heat-treated at 600°C
and 800°C. Influence of drying process and treatment temperature on the crystalline phase composition
and photocatalytic activity were analyzed. The photocatalytic activity of the TiO2 dried by common and
far infrared drying is higher than that of the TiO2 dried by vacuum and supercritical drying after treated at
600°C. The photocatalytic activity of the TiO2 dried by common and far infrared drying is lower than that
of the TiO2 treated by the other two drying methods after treated at 800°C.
Abstract: Nanosize anatase TiO2 powders have been synthesized by hydrothermal synthesis by using
technical grade TiOSO4 as precursor and urea as precipitating agent. The initial pressure of the reaction
system was set at 6 MPa. Stirring speed was fixed at 300r/min. The reaction system reacted at the
temperature ranged from 110 to 150°C for holding 2hrs to 8hrs and the concentration of the precursor was
ranged from 0.25M to1.5M. XRD patterns show that the synthesized powders are in the form of anatase
phase. Calculated grain size is ranged from 6.7 to 8.9nm by Scherrer method from the line broadening of
the (101) diffraction peak of anatase. The specific surface area of the powders synthesized under different
conditions is ranged from 124 to 240m2/g. The grain size of the powders increases with the increase of the
reaction temperature, holding time and precursor concentration, respectively. The specific surface area
decreases with the increase of reaction temperature and holding time, and does not obviously change with
the change of precursor concentration when the concentration of the precursor is less than 1M. However,
when the concentration is higher than 1M, the specific surface area will decrease quickly with the increase
of the precursor concentration. XRD and DSC-TG analysis shows that the synthesized anatase TiO2 will
begin to transform to rutile TiO2 at about 840°C. When heated to 1000°C for holding 1h, the anatase
powders will transform to rutile completely.