Toward Tunable Adsorption Properties, Structure, and Crystallinity of Titania Obtained by Block Copolymer and Scaffold-Assisted Templating

Nanostructured titania and composite titania materials were synthesized for the first time by a one-pot strategy in an aqueous solution containing Pluronic P123 block copolymer and suitable precursors. The strategy can be considered as more facile, environmentally friendly, and less expensive as compared to the existing ones that require use of organic solvents. In the case of composites, silica and alumina particles were used as a structure protecting scaffold and composite components. This synthesis strategy allowed tuning of adsorption and structural properties of the resulting materials; namely, the specific surface area was varied from 84 to 250 m² g^–1, total pore volume from 0.11 to 0.46 cm³ g^–1, and the pore width from 5.6 to 11.2 nm. All samples studied but one showed exclusively anatase phase, and the composites obtained with silica scaffold showed tunable degree of crystallinity. The proposed approach to tailoring the surface and structure properties of titania is especially important for the development of high performance materials for photocatalysis, lithium-based batteries, and dye-sensitized solar cells

Microwave-Assisted Synthesis of Porous Carbon–Titania and Highly Crystalline Titania Nanostructures

Porous carbon–titania and highly crystalline titania nanostructured materials were obtained through a microwave-assisted one-pot synthesis. Resorcinol and formaldehyde were used as carbon precursors, triblock copolymer Pluronic F127 as a stabilizing agent, and titanium isopropoxide as a titania precursor. This microwave-assisted one-pot synthesis involved formation of carbon spheres according to the recently modified Stöber method followed by hydrolysis and condensation of titania precursor. This method afforded carbon–titania composite materials containing anatase phase with specific surface areas as high as 390 m² g^–1. The pure nanostructured titania, obtained after removal of carbon through calcination of the composite material in air, was shown to be the anatase phase with considerably higher degree of crystallinity and the specific surface area as high as 130 m² g^–1. The resulting titania, because of its high surface area, well-developed porosity, and high crystallinity, is of great interest for catalysis, water treatment, lithium batteries, and other energy-related applications

Synthesis of Porous Crystalline Doped Titania Photocatalysts Using Modified Precursor Strategy

We propose a new strategy for the synthesis of porous crystalline doped titania materialsdubbed the modified precursor strategy. The modified precursors are prepared by reacting generic titania precursors with organic acids in order to introduce “carbonizable” groups into the precursor’s structure, so that carbon–titania composites can form upon carbonization. The resulting carbon framework serves as a scaffold for TiO₂ and supports the structure during crystallization. Afterward, removal of the carbon scaffold through calcination results in titania with a well-developed structure and high crystallinity. The titanias synthesized according to this strategy, using common organic acids as the modifiers, have specific surface areas reaching 100 m² g^–1 and total pore volumes exceeding 0.20 cm³ g^–1, even after crystallization at temperatures from 500 to 1000 °C. The materials possess high crystallinity and tunable phase composition, and some show visible light absorption and significantly narrowed band gaps (2.3–2.4 eV). Photocatalytic degradation of methylene blue proved that these photocatalysts are active under visible light. All tested titanias show an excellent photocatalytic performance due to the combined effects of the well-developed structure, high crystallinity, and narrow band gap. This strategy can easily be adopted for the preparation of other porous crystalline materials