This work reports the potential of atmospheric pressure dielectric barrier discharge (DBD) plasma for synthesizing Ruthenium dioxide (RuO2) nanomaterials with various morphologies. The RuO2 nanomaterials were grown on four kinds of substrates including copper, silicon, glass and polyethylene terephthalate. The feed gas to the DBD plasma reactor was Ar or Ar + O-2 mixture, which creates an inert or oxidation atmosphere, respectively. The prepared nanomaterials were characterized by using X-ray diffraction spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The morphology of the RuO2 nanomaterials prepared by exposing the precursor to the DBD plasma was found to depend strongly on the characteristics of the substrate as well as on the composition of the feed gas. Spherical and sheet shaped nanomaterials prepared using the above technique was analyzed for their size dependent photocatalytic behavior in the presence of visible light. Methylene blue degradation was found mainly dependent on the nanomaterial concentration and at the same time sheet shaped nanomaterials showed more catalytic activity as compared to spherical shaped RuO2. (C) 2013 Elsevier B.V. All rights reserved.