As(III) Removal by Palladium-Modified Nitrogen-Doped Titanium Oxide Nanoparticle Photocatalyst

Removal of arsenic species from water by palladium-modified nitrogen-doped titanium oxide (TiON/PdO) nanoparticles was investigated with and without visible light. For the first time, a high degree of As(III) removal under visible light illumination was demonstrated on oxide photocatalysts. Over 2 orders of magnitude decrease of As(III) concentration in water was observed in 1 h as the As(III) concentration was reduced below the U.S. Environmental Protection Agency standard (10 μg/L) by TiON/PdO photocatalyst. Such an efficient removal of As(III) was shown to result from the combined effects of strong adsorption and photooxidation by TiON/PdO, where an enhanced photocatalytic activity under visible light illumination than nitrogen-doped titanium oxide (TiON) was derived from the strong optoelectronic coupling between PdO and TiON