Synthesis and characterization of mesoporous TiO2 assembled as microspheres

In the work presented here, we report the successful synthesis of highly porous (219 m2/g) mesostructured titania powder assembled as microspheres of uniform wormlike channels of ∼6–7 nm widths by spray pyrolysis of a titania sol prepared by templating approach using P123 pluronic block copolymer (BC). This method involves the preparation of a Ti4+-sol containing titanium tertraisopropoxide (TTIP), pluronic BC P123, 2-propanol, acetyl acetonate (ACAC) and hydrochloric acid (HCl) as well as H2O followed by spray pyrolysis of the obtained sol into the hot zone of a pre-heated reactor at 800 °C, 900 °C and 1000 °C. For all of these pyrolyzed samples, the formation of anatase as the major phase along with rutile as the minor one could be confirmed. The appearance of wormlike mesopores rather than highly ordered cubic or hexagonal mesostructures is related to the lack of appropriate drying conditions normally applied to induce self assembly as well as formation of rather large titania crystallite sizes.