Nanostructured titanium dioxide (TiO₂) is widely used in paints, cosmetics, air purifiers and solar cells. One popular method to synthesize TiO₂ is by sol-gel method to crystallize the anatase phase via thermal, hydrothermal or chemical means. However, these processes often require long treatment time and proceed at high pressure and temperature. _{2 2 2}...[ Read more ]

Nanostructured titanium dioxide (TiO₂) is widely used in paints, cosmetics, air purifiers and solar cells. One popular method to synthesize TiO₂ is by sol-gel method to crystallize the anatase phase via thermal, hydrothermal or chemical means. However, these processes often require long treatment time and proceed at high pressure and temperature.

A novel continuous flow microwave crystallization of TiO₂ was investigated for fast, energy efficient, low temperature process for producing photoactive TiO₂ catalyst for pollution treatment. The effect of microwave operating parameters on TiO₂ crystal size, crystallinity, and surface area was investigated. Microwave-crystallized samples were analyzed by X-ray diffraction (XRD), Micro-Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ physisorption. Temperature in the reaction mixture was identified as the key factor of the TiO₂ crystallization followed by duration of microwave. Higher temperature resulted in better TiO₂ crystallization. Modified TiO₂ using zeolite doped method and template method were also presented in this study. Modified TiO₂ by zeolite doped method enhanced the surface area of the particles for photocatalysis. In the modified TiO₂ templating method, TiO₂ rod was synthesized in order to benefit photocatalyst recovery.

Microwave-crystallized TiO₂ samples have adsorption ability toward diclofenac, a common endocrine disrupting chemicals (EDCs) found in water, and results in enhanced photocatalytic degradation compared to TiO₂ obtained by thermal treatment. Crystallinity and adsorption ability are the critical factors for photocatalyic oxidation performance based on the studies.