Enhanced photoresponse towards visible light in Ru doped titania nanotube

Doping of ruthenium by the ion exchange method to the hydrothermally synthesized titania nanotube (TiNT) was found to be an effective photocatalyst active under visible light for methylene blue dye decoloration. The well dispersed and well embedded ionized ruthenium particles of about ∼2–4 nm significantly reduced the band gap energy of synthesized TiNTs from 3.1 eV to 2.56 eV in (Ru(IE)/TiNT). The loading method, size of ruthenium particles and metal dispersion pattern at the nanotube textures have great influence on its photocatalytic performances exhibiting higher photocatalytic activity (>80%) of methylene blue dye. However, large aggregated ruthenium particles (sizes ∼12–60 nm) on Ru(IM)/TiNT prepared by impregnation method failed to respond in visible light. The prepared catalysts were analysed by TEM, FESEM, FE-SEMEDX, XRD, UV–vis DRS spectra, XPS and BET surface area techniques.