Abstract:
Nano-structured materials have become a prominent research topic in recent years due
to their numerous distinguishing characteristics. Among all the transition metal
oxides, TiO2 is a compound of great importance due to its remarkable catalytic and
distinctive semiconducting properties. Nano TiO2 can be used as a strong oxidizing
agent with a large surface area which implies high photo-catalytic activities. Some
extensive research studies on the modification, preparation, and characteristics of
nanomaterials have been published, allowing us to keep track of progress in this
sector. In the case of the synthesis of pure TiO2, the two main procedures, such as
sulfate and chloride processes, are employed where both require concentrated
corrosive acids and extreme temperatures, such as 1000 °C, in open operations, which
resulted in significant expenses and pollution. Recently, a closed method has been
developed, including rotatory autoclaving, refluxing, and stationary solvothermal
treatment of ilmenite below 170 °C, which can be used to reduce costs and
environmental effects. The as-synthesized product is 100% pure titanium dioxide in
its amorphous state (24% crystallinity). This can be converted into over 99% pure
anatase phase with 90% crystallinity and 100% pure rutile phase nanorods with 98%
crystallinity by calcining at 350 and 650 °C, respectively. The direct band gaps of the
three materials are 3.40, 3.60, and 3.15 eV, respectively. So, the new method can be
used to modify the previously existing technology by using newly established
processes for three phases in rutile, anatase, and amorphous state. As the world is
progressing towards more ecologically friendly and sustainable energy, this procedure
might be applied to the synthesis of pure TiO2, where the substance can be employed
in solar cell fabrication because solar cells are still encountering scientific and
technological challenges in their commercialization.
