International Journal Of Scientific & Engineering Research, Volume 5, Issue 2, February-2014 ISSN 2229-5518 Comparative Study on Titania Nanoparticles Synthesized by Mechanical, Sonomechanical and Sol-gel methods Shamim Ahamad Khan* a , Irfan Ali Khan a , Mohd. Sajid Khan b , Manaal Zahera b Abstract- Titania nanoparticles synthesized by three different methods like mechanical method (high energy ball milling or HEBM), sonomechanical method and sol- gel method. In this work, the high energy ball milling (HEBM) was applied to synthesize nanoparticles (NPs) of TiO2 from its microcrystalline powder for 10, 20 and 30 hours respectively. The titania NPs also synthesized by sonomechanical and sol-gel method. Eventually, they were characterized by X- ray diffraction (XRD) and UV-Vis absorption spectroscopy. XRD results stated the complete phase formation of titania nanoparticles and comparatively correlated the crystal size. UV-Vis absorption spectroscopy determines the energy band gap of titania nanoparticles by using Tauc Relationship. Keywords- Titania naoparticles, HEBM, Sonomechanical, XRD, UV-Vis absorption spectroscopySol-gel, Band gap, Optical properties. 1INTRODUCTION Nanoscale materials have very attractive properties, much attention due to their unique characteristics, which are not found in bulk materials. For instance, the reactions of NPs with other materials become more efficient due to their high surface-to-volume ratios, in addition to the high percentage of atoms at the grain boundaries. Some studies have found that in last three decades, the application of semiconductor heterogeneous photocatalysts, particularly titania (TiO2) in the photo decomposition of toxic organic pollutants has been widely examined [1-3]. Titanium dioxide (TiO2) has potential applications to remove stain or pigment. The nano sized titania act as catalytic, photocatalytic, dye sensitized photovoltaic cells, sensors and antimicrobial agent. Their use has always expanded for novel applications such as enhancement of self-sensitizing; self-cleaning and germ free tiles for hospitals, restaurants, kitchens etc. Coating of nano sized titania on glass, decomposes the organic molecules particularly on the glass i.e. self-cleaning capability [4]. Different methods have been developed for the synthesis of TiO2 nanoparticles like chemical precipitation [5], hydrothermal crystallization [6], vapor phase condensation, sputtering, mechanical methods, sonomechanical methods and sol-gel methods. Various studies have beenreported for the synthesis of nanocrystalline materials by mechanical milling, mechanical alloying and mechanochemical processing [7]. Not long ago, mechanical milling has proved as a simple technique which can produce nanocrystalline powders in ———————————————— x a* Department of Applied Physics (Nanoscience), Integral University, Kursi Road, Lucknow-226026, India. PH-+91-522-2890812, 2890730; Fax: +91-522-2890809 E-mail: khanshamimahamad21@gmail.coms x b Department of Biosciences, Integral University, Kursi Road, Lucknow-226026, India. large quantities with modified properties [8-12]. In this paper we discuss the TiO2 nanoparticles synthesis by mechanical, sonomechanical and chemical process in order to illustrate the influence of crystallite size. 2EXPERIMENTAL PROCEDURE 2.1 Synthesis Commercially available TiO2 powder (Otto 99.9%) was milled in steel jar of 250 mL by using the hardened balls of different sizes (05 mm, 10 mm and 20 mm) from 10 to 30 hours. Bulk 150gm of TiO2 is taken in grinding jar and 75 mL methanol is added in bulk titania powder, therefore the paste of titanium dioxide is formed then 10 mm diameter of 50 balls are added in grinding jar, finally the grinding jar is clamped in ball mill machine for 10 hrs at 350 rpm with interval 1 hr and reverse rotation 10 minute. After the completion of 10 hour, material is placed in oven at 70 0 c for 3 hrs. Further the process repeated by using same material and condition for 20 hrs and 30 hrs. Sonomechanical method is more effective because the ultra sonic waves break down the weak forces and some chemical bonding present in the material, which cannot be break down by simple milling. In this process the ultra sonic waves are provided to the sample by the instrument ultra sonic processor and bath ultra sonicator. In this new type of sonomechanical synthesis first of all 50 gm of titanium dioxide is taken in 250 mL beaker then 30 mL of methanol is added, therefore liquid suspension is formed. This liquid suspension is placed for 30 minute for ultra sonication with amplitude 40%, pulse 0.5- 1.0. After that the grinding of material takes place by ball milling. Sol-gel method is a one of the best technique known as chemical solution deposition. In this synthesis process 7.4 mL of titanium (IV) isopropoxide (alpha acer) was added drop by drop in 1M HNO3 aqueous solution and then IJSER © 2014 http://www.ijser.org 900 IJSER