Structure of Ru–Ti oxide aerogels: a SANS study

Small-angle neutron scattering (SANS) has been used to characterize Ru–Ti oxide aerogels annealed under various atmospheres and temperatures. The pores were filled with H2O/D2O solutions that match the scattering properties of either RuO2 or TiO2, therefore scattering from the remaining unmatched phase is measured independently. The structure of the RuO2 and TiO2 components of the aerogel detected by SANS depends more on annealing temperature than annealing atmosphere. The results are consistent with a branched, polymeric network made up of 8–16 nm TiO2 particles and <5-nm RuO2 particles. The SANS results are supported by TEM. This study demonstrates that contrast-matching SANS is complementary to other techniques for characterizing the structure of two-phase aerogels.