Electron–hole separation for novel composite systems comprised of secondary building units formed
from different compounds is investigated with the aim of finding suitable materials for photocatalysis.
Pure and mixed SOD and LTA superlattices of (ZnO)12 and (GaN)12, single-shell bubbles are constructed
as well as core@shell single component frameworks composed of larger (ZnO)48 and (GaN)48 bubbles
with each containing one smaller bubble. Enthalpies of formation for all systems are comparable with
fullerenes. Hole and electron separation is achieved most efficiently by the edge sharing framework
composed of (GaN)12@(ZnO)48 double bubbles, with the hole localised on the nitrogen within the smaller
bubbles and the excited electron on zinc within the larger cages