Boron oxynitride nanoclusters on tungsten trioxide as a metal-free cocatalyst for photocatalytic oxygen evolution from water splitting

Here we show that B(2)O(3-x)N(x) nanoclusters can be formed on the surface of WO(3) particles by a combination of thermal oxidation of tungsten boride (WB) in air and the subsequent nitriding process in gaseous ammonia. The resultant nanoclusters are found to play an apparent role in improving the photocatalytic oxygen evolution of WO(3) by promoting the surface separation of photoexcited charge-carriers.