Synthesis and characterisation of macro-mesoporous titania

In this work three-dimensionally ordered macroporous titania has been prepared using arrays of latex particles with different compositions as templates and titanium isopropoxide as titania precursor. The templates and the titania samples have been characterised by scanning and transmission electron microscopy and by nitrogen adsorption at 77K. In the imprinted samples the titania skeleton encloses a network of interconnected porous sub-lattices in the macropore and mesopore ranges. The pore system includes as well as the macropores, replica of the latex particles, the porosity inside the macropores wall and a macro-mesoporous sub-lattice formed by the octahedral and tetrahedral holes in the template partially mineralised. The macropores are interconnected by large windows at the positions of the contact points of the latex particles in the template and the mesopores inside the walls interconnect the macroporous and macro-mesoporous sub-lattices. The surface area and pore size distributions of these samples can be related to nanostructural parameters that are affected by the chemical composition and particle size of the template, the concentration of the titania precursor and the mineralization degree. The results suggest that by selecting the precursor and template and the conditions of the sol–gel reactions together with the improvement in the infiltration process, the surface area should be optimised and the size distribution of mesopores inside the macropore wall should be controlled.