  A two-dimensional layer of oxide reveals itself as a essential element to
drive the photocatalytic activity in a nanostructured hybrid material, which
combines high-quality epitaxial graphene and titanium dioxide nanoparticles. In
particular, it has been revealed that the addition of a 2D Ti oxide layer
sandwiched between graphene and metal induces a p-doping of graphene and a
consistent shift in the Ti d states. These modifications induced by the
interfacial oxide layer induce a reduction of the probability of charge carrier
recombination and enhance the photocatalytic activity of the heterostructure.
This is indicative of a capital role played by thin oxide films in fine-tuning
the properties of heterostructures based on graphene and pave the way to new
combinations of graphene/oxides for photocatalysis-oriented applications.
