Crystal growth by leaps and bounds based on self-assembly: insight from titania

In this paper, we investigated the discontinuous growth of TiO2 nanoparticles (NPs) in a simple hydrothermal system containing oleic acid (OA), oleylamine (OM) and H2SO4. By examining the crystal growth processes of TiO2 NPs in detail, we found that the size of NPs was increased by leaps and bounds based on the self-assembly of TiO2 nano-subunits. By tuning the reaction parameters, the nano-subunits grow firstly into mesocrystals, and finally uniform porous hollow NPs through the mechanisms of both oriented attachment and Ostwald ripening.