RESEARCH PAPER The formation of titanium dioxide crystallite nanoparticles during activation of PAN nanofibers containing titanium isopropoxide Fahimeh Mehrpouya • Hossein Tavanai • Mohammad Morshed • Mehran Ghiaci Received: 25 February 2012 / Accepted: 17 July 2012 Ó Springer Science+Business Media B.V. 2012 Abstract Activated carbon (AC) can act as an important carrier for TiO 2 nanoparticles. TiO 2 nano- particle can be fabricated by the hydrolysis and condensation of titanium alkoxides like titanium isopropoxide. This study showed that the formation of titanium dioxide crystallite nanoparticle during activation of PAN nanofibers containing titanium isopropoxide leads to the formation of mainly anatase crystal TiO 2 nanoparticle in AC nanofibers, with a good dispersion in both the longitude and cross section of nanofibers. The TiO 2 crystallite size lies in the range of 7.3–11.3 nm. The dispersion of TiO 2 nano- particles in the matrix of AC nanofibers is far superior to the direct mixing of TiO 2 nanoparticles in the original electrospinning solution. Keywords Titanium dioxide  Nanocomposite  Anatase  Rutile  Activated carbon nanofibers Introduction Titanium dioxide (TiO 2 ) with fascinating properties such as chemical stability, corrosion resistance, and non-toxicity has a wide range of applications, namely air and water purification, catalysis or photocatalysis, white pigments for printing and coating, counter electrode in light, solar or electrochemical cells, sensors, food additive and cosmetic (Boschaloo et al. 1997; Alivov and Fan 2009; Carp et al. 2004; Yang et al. 2008; Matos et al. 1999). The annual consump- tion of TiO 2 is reported to be 4 mT, mostly in anatase and rutile crystal form. TiO 2 exists in four crystal forms, namely, anatase, rutile, brookite, and TiO 2 (B) (Wang et al. 2011). From these four crystal forms, only anatase and rutile show photocatalytic activity. Further information on anatase and rutile TiO 2 can be obtained from references (Tan et al. 2011; Masuda and Kato 2009; Wu et al. 2011; Wang et al. 2011; Defarials et al. 2005; Chu et al. 2008). TiO 2 is one of the most frequently used photocata- lysts. Anatase to rutile phase transformation strongly affects the applicability of TiO 2 as catalyst or photocat- alyst. Apart from temperature, other factors like surface or network defects, particle size, pressure and porosity affect the transformation (Puma et al. 2008; Hashimoto et al. 2007). Mills and Lee (2002) considered TiO 2 as the best and most available semi-conductor photocatalyst with merits like occurrence of photocatalytic reactions at room temperature, non-toxic products or by-products, cheap price, compatibility with a range of other F. Mehrpouya  H. Tavanai (&)  M. Morshed Department of Textile Engineering, Center of Excellence in Applied Nanotechnology, Isfahan University of Technology, 84156-83111 Isfahan, Iran e-mail: tavanai@cc.iut.ac.ir M. Ghiaci Department of Chemistry, Isfahan University of Technology, 84156-83111 Isfahan, Iran 123 J Nanopart Res (2012) 14:1074 DOI 10.1007/s11051-012-1074-3