*2.3.2. Merits*

Rahal et al. have prepared TiO<sup>2</sup>

20 Titanium Dioxide - Material for a Sustainable Environment

TiF<sup>4</sup>

lization of TiO<sup>2</sup>

increase in H<sup>2</sup>

bromide (CTAB, 11 mmol) and urea (2.4 g, 40 mmol) in 200 ml H<sup>2</sup>

CTAB is used as a surfactant to control morphology and (NH<sup>2</sup>

and centrifugation is done to take out less dense particles.

Martínez et al. [67] have recently reported TiO<sup>2</sup>

tetra isopropoxide in 50 ml of H<sup>2</sup>

SO<sup>4</sup>

**Figure 17.** SEM images (a–d) of TiO<sup>2</sup>

5 min [66].

Rhodamine B dye and complete degradation is observed within 1 h.

SO<sup>4</sup>

concentration increases the particle size.

hierarchical structures by mixing cetyltrimethyl ammonium

) 2

To this reaction mixture, cyclohexane and 1-pentanol are added after stirring of 30 min. Then,

Flower-shaped HNSs made of nanoparticle agglomerates (**Figure 17**) are produced with anatase phase [66]. Microwave treatment even for 5 min provides enough time for crystal-

at 120°C for 2 h. Anatase Titania is formed as a result of this scheme. Concentration of H<sup>2</sup>

is changed to study the effect on particle size. Cauliflower-shaped HNSs are obtained. The

nanoparticles. The prepared structures are utilized in photodegradation of

 (5.94 g, 48 mmol) is added to the solution and whole liquid media is transferred to Teflonlined microwave reactor at 800 W. The mixture is irradiated under microwaves for 5 min at 120°C. The product is then washed thoroughly to remove impurities and other compounds

O for hydrolysis (**Figure 18**).

SO<sup>4</sup>

C=O provides steric hindrance.

HNSs prepared by stirring 3 ml of titanium

and subsequent microwave treatment in a Teflon vessel

hierarchical structures having flower-like shapes after microwave irradiations for


#### *2.3.3. Demerits*

