Tantalum nitride nanoparticles, as visible-light photocatalysts were synthesized by a two-step homogeneously chemical reduction without any polymers and templates. The well-crystallized Ta3N5 nanoparticles with a range of 20-50 nm in size have been characterized by a number of techniques, such as XRD, XPS, SEM, TEM, BET and UV-Vis spectrum. Most importantly, the Ta3N5 nanoparticles with good stability exhibited higher photooxidation activities in the water splitting and degradation of methylene blue under visible light irradiation than bulk Ta3N5 particles and commercial P25 TiO2, demonstrating that Ta3N5 nanoparticle is a promising candidate as a visible-light photocatalyst. Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.