A precursor route to prepare tantalum (V) nitride nanoparticles with enhanced photocatalytic activity for hydrogen evolution under visible light

Nanoparticulate Ta3N5 was prepared by nitridation of nanoparticulate Ta2O5 precursor in an attempt to improve the photocatalytic activity for H-2 evolution from aqueous methanol solution under visible light (lambda > 420 nm). When platinum (Pt) was deposited in situ as a H-2 evolution cocatalyst, the as-prepared Ta3N5 with a primary particle size of 30-50 nm exhibited enhanced activity, three times higher than that of bulk Ta3N5 particles 300-500 nm in size. The improvement in activity arises from a lower density of defect sites, which is favorable for electron migration from the Ta3N5 bulk to the surface and/or for electron transfer from the conduction band of Ta3N5 to the loaded Pt. (C) 2009 Elsevier B.V. All rights reserved.