Abstract: Nanophotocatalysts such as titanium (TiO2), zinc (ZnO), and iron (Fe2O3) oxides can be used in organic pollutants oxidation, and in many other applications. But among the challenges for technological application (scale-up) of the nanotechnology scientific developments two aspects are still little explored: research on environmental risk of the nanomaterials preparation methods, and the study of nanomaterials properties and/or performance variability. The environmental analysis was performed for six different methods of ZnO nanoparticles synthesis, and showed that it is possible to identify the more environmentally compatible process even at laboratory scale research. The obtained ZnO nanoparticles were tested as photocatalysts, and increased the degradation rate of the Rhodamine B dye up to 30 times.
Abstract: Magnetic and semiconductor nanomaterials exhibit
novel magnetic and optical properties owing to their unique size and
shape-dependent effects. With shrinking the size down to nanoscale
region, various anomalous properties that normally not present in bulk
start to dominate. Ability in harnessing of these anomalous properties
for the design of various advance electronic devices is strictly
dependent on synthetic strategies. Hence, current research has focused
on developing a rational synthetic control to produce high quality
nanocrystals by using organometallic approach to tune both size and
shape of the nanomaterials. In order to elucidate the growth
mechanism, transmission electron microscopy was employed as a
powerful tool in performing real time-resolved morphologies and
structural characterization of magnetic (Fe3O4) and semiconductor
(ZnO) nanocrystals. The current synthetic approach is found able to
produce nanostructures with well-defined shapes. We have found that
oleic acid is an effective capping ligand in preparing oxide-based
nanostructures without any agglomerations, even at high temperature.
The oleate-based precursors and capping ligands are fatty acid
compounds, which are respectively originated from natural palm oil
with low toxicity. In comparison with other synthetic approaches in
producing nanostructures, current synthetic method offers an effective
route to produce oxide-based nanomaterials with well-defined shapes
and good monodispersity. The nanocystals are well-separated with
each other without any stacking effect. In addition, the as-synthesized
nanopellets are stable in terms of chemically and physically if
compared to those nanomaterials that are previous reported. Further
development and extension of current synthetic strategy are being
pursued to combine both of these materials into nanocomposite form
that will be used as “smart magnetic nanophotocatalyst" for industry
waste water treatment.