Efficient visible-light-driven water oxidation by single-crystal Ta3N5 nanoparticles

Ta3N5 is regarded as a promising photocatalyst for solar water splitting because of its excellent visible light absorption characteristics and simple composition. Conventional Ta3N5 photocatalysts prepared from oxide precursors typically comprise aggregated polycrystalline particles with defects and grain boundaries that reduce the water oxidation activity of the material. In the present work, well-dispersed Ta3N5 nanoparticulate single crystals were synthesized via a mild nitridation process using pure Ta metal nanopowder or Ta nanopowder mixed with NaCl. The resulting high-quality Ta3N5 nanoparticles, after loading with an oxygen evolution cocatalyst, exhibited impressively high photocatalytic performance during O2 evolution from a sacrificial AgNO3 solution, with an apparent quantum yield of 9.4% at 420 nm. Our findings suggest a new approach to the facile fabrication of nanostructured single-crystal photocatalysts for efficient solar water splitting, based on the use of metal nanopowders.