Abstract: Industrial titanyl sulfate (TiOSO₄) solution was used as inorganic titanium source to prepare mesoporous titania via composite template synthesis route, using cetyltrimethylammonium bromide  and tri-block copolymer (EO₂₀PO₇₀EO₂₀) as structure-directing agents under high acidic conditions. The precursor was prepared by controlling the hydrolysis and condensation rate of industrial TiOSO₄ solution by adjusting pH. Mesoporous titania was obtained after template removal by ozone oxidizing, multi-step extraction and then by step-by-step calcination. The results showed mesoporous titania was hexagonal mesophasse, with BET specific surface area of 205.7 m²/g, average pore diameter of 3.28 nm, thermal stability and with anatase nanocrystalline phase. The formation process of mesoporous titania was via static (S⁺I^-) and hydrogen bond interaction (N⁰I⁰) at the interphase of the composite surfactants. Titanium primary hydrolyzed colloid particles aggregated around the micelle, and then condensed to form the mesostructure. The whole process could be described as cooperative formation mechanism for mesoporous titania. 

Key words: Titanyl sulfate; Composite template synthesis; Mesoporous titania; Template removal; Formation mechanism

More detailed descriptions are listed in the full paper. Here are some representative figures and formation mechanism sketch map.

Figures:

Fig.1 Low angle XRD pattern for the synthesized titania

  Fig.2 Wide angle XRD pattern for mesoporous titania

Fig.3 Nitrogen isotherms (A) and pore size distribution (B) for mesoporous titania

Fig.4 HRTEM micrograph for mesoporous titania

Fig.5 Sketch map of mesoporous titania formation mechanism via supramulecular induced hydrolysis of industrial TiOSO₄