*2.2.1. Synthesis of pristine TiO2*

Titanium tetra iso-propoxide (TTIP) was used as Titanium precursor and methoxyethanol as organic solvent. 20 ml TTIP is added to 40 ml methoxyethanol and mixed using magnetic stirrer. The pH of solution is adjusted to value 3 using 1 M HNO<sup>3</sup> , which also catalyzes the hydrolysis process. The mixing is continued until viscous gel is formed, which is then dried under IR lamp and pulverized to obtain amorphous powder. The pure anatase TiO<sup>2</sup> nanopowder is formed after calcining the amorphous powder at 450°C for 1 hour. The chemical reactions occurring during hydrolysis and condensation in the synthesis are listed below.

 Ti [OR] <sup>4</sup> + 4 HOR' → Ti [OH] <sup>4</sup> + ROR' (Hydrolysis)

 Ti [OH] <sup>4</sup> → TiO<sup>2</sup> + 2 H2 O (Condensation)
