High-efficiently visible light-responsive photocatalysts : Ag ₃PO₄ tetrahedral microcrystals with exposed {111} facets of high surface energy

In this article, single-crystalline tetrahedral Ag₃PO ₄ microcrystals with exposed {111} facets was successfully synthesized via a facile wet chemical method. The tetrahedral Ag ₃PO₄ with exposed {111} facets showed the highest photocatalytic activity in visible light irradiation among the {111}, {110} and {100} facets. By DFT calculations, it is demonstrated that the surface energy of the {111} facets is higher than that of the {110} and {100} facets. It was found that the largest band gap of the Ag₃PO₄ {111} surface is likely to suppress the recombination of electron-hole pairs by exploring the electronic structures of the different surfaces of Ag ₃PO₄. Meanwhile, the dispersion between the valence bands and conduction bands of the {111} surface is beneficial for the separation of photogenerated electrons and holes on the {111} surface, which further improves the photocatalytic activity of the {111} surface. © 2013 The Royal Society of Chemistry.