Nano-oxides are essential materials in nanotechnology as their demand has greatly expanded. The materials are used in a variety of applications including colloid science, environmental remediation, catalysis and photo-catalysis, electronics, medicinal applications, separations, thin films, inks and disinfection. The efficient production of nanoparticles is likely to play a key role in the future of the chemical industry.
ZnO
ZnO, a wide-band gap semiconductor (3.37eV) at room temperature with a large exciton binding energy (60 meV), is a multifunctional material for a variety of practical applications due to its excellent physical and chemical properties. One-dimensional nanostructures of ZnO have attracted great interest because of their unique and fascinating optical, electrical, mechanical and piezoelectric properties together with their wide use in fundamental scientific research and potential technical applications, such as nano-ultraviolet lasers, piezoelectric devices, field emissions, gas sensors, dye-sensitized solar cells and photocatalyts.
Disinfectant property
Metal oxides like ZnO as well as sulphides like ZnS have efficient disinfectant rate due to increased surface to volume ratio which is an important property. In the presence of UV light the valence electrons in the nanoparticles are excited to form electron-hole pairs. These negative electrons and positive holes are strong oxidizers. When harmful substances like pesticides stick to the positive holes, they are disintegrated into harmless compounds. The excited electrons are also injected into bacteria in contact with nanoparticles and hence act as a disinfectant. This technology is used to decompose toxic pesticides, which take a long time to degrade under normal conditions.
Synthesis of ZnO
A simple and efficient route to synthesis ZnO nanowires at a low temperature is by thermal CVD. Thermal CVD of ZnO synthesis is usually viewed as cheap, low-toxic and efficient methods to fabricate various ZnO nanostructures with high crystal quality. Using these method ZnO nanowires can be quickly synthesized in 10 min without catalysts. The high crystal quality of synthesized nanowires show strong ultraviolet (UV) emission in their photoluminescence spectra.
Desert Nano-Roses of Nickel Oxides
Nano-scale nickel oxides and mixed-metal oxides can be fabricated using microwave irradiation in pure water into unique desert-rose-shaped nanostructures. These materials exhibit promising performance as nanocatalysts for CO oxidation and in energy storage devices.
Other oxides
Nanoparticles of ZrO2, TiO2, and CeO2 have been produced directly after the treatment of the suspension. Nanopowders of Y2O3 and La2O3 have been obtained after calcination of the hydroxide forms. Phosphor-based lanthanide nanomaterials can be used in a variety of quantum dot-type applications, and are particularly suitable for medical and pharmaceutical research. Nano Oxides, Carbonates and Hydroxides of Magnesium exhibit unique properties and can be used as a catalyst in electronics and ceramics, oil refining, in textile industry, for the synthesis of brand new, high-performance fire retarding agents and as an ideal material for the fabrication of industrial fabrics.