Synthesis and facet-dependent photocatalytic activity of strontium titanate polyhedron nanocrystals

Cubic-perovskite (SrTiO₃) has a great potential to be utilized in a wide range of applications. However, currently very little is known about the shape and facet effects of SrTiO₃ on their physicochemical properties. This is largely owing to the difficulties in controlling the morphology of facets during synthesis. Herein, we describe a facile route for the facet- and size-controlled fabrication of singlecrystalline SrTiO₃ triangular prisms with highly exposed {101} side faces and {111} end faces. Theoretical and experimental studies of their photocatalytic performance have shown that triangular prisms exhibit superior photocatalytic activities than nanocubes with exposed (001) faces for the degradation of organic contaminants, which may be primarily attributed to the much higher surface energy of {101} facets (2.97 J/m²) and {111} facets (2.80 J/m²) than of that of {001} facets (0.98 J/m²).