Saikia, P.Miah, A.T.Das, P.P.2026-02-052017Journal of Chemical Sciences, 2017, 129, 1, pp. 81-939743626https://doi.org/10.1007/s12039-016-1203-0https://idr.nitk.ac.in/handle/123456789/25808Highly improved catalytic reductive degradation of different organic dyes, in the presence of excess NaBH<inf>4</inf> over Au/CeO<inf>2</inf>-TiO<inf>2</inf> nano-hybrid as the catalyst is reported in this study. CeO<inf>2</inf>-TiO<inf>2</inf> nanocomposite was prepared by a facile co-precipitation method using ultra-high dilute aqueous solutions. Small amount of Au (only 1 wt%) was loaded onto the nanocomposite material by deposition-precipitation with urea (DPU) method to fabricate the ternary Au/CeO<inf>2</inf>-TiO<inf>2</inf> nano-hybrid. The catalysts were characterized by the representative techniques like XRD, BET surface area, ICP-AES, UV-Vis diffuse reflectance spectroscopy, TEM and XPS. The Au/CeO<inf>2</inf>-TiO<inf>2</inf> nano-hybrid along with NaBH<inf>4</inf> exhibited remarkable catalytic activities towards all the probed dyes, namely Methylene Blue, Methyl Orange, Congo Red, Rhodamine B and Malachite Green, with a degradation efficiency of ?100% in a short reaction time. The degradation reaction followed pseudo-first-order kinetics with respect to the concentration of the dye. Different parameters that affect the rate of the reaction are discussed. A plausible mechanism for methylene blue degradation has also been proposed. [Figure not available: see fulltext.] © 2017, Indian Academy of Sciences.Aromatic compoundsAtomic emission spectroscopyAzo dyesCatalystsDegradationDyesNanocompositesPrecipitation (chemical)Reaction kineticsSolutionsTitanium dioxideUreaDeposition precipitationDilute aqueous solutionGold NanoparticlesMethylene blue degradationsNano hybridsOrganic dyePseudo first-order kineticsUV-Vis diffuse reflectance spectroscopyCatalyst activity