http://nopr.niscair.res.in/handle/123456789/12463 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12479 Title: BaCrO₄ assisted visible light induced advanced oxidation process for mineralizing Azur B <br/> <br/>Authors: Pare, Brijesh; Singh, Vijendra; Jonnalagadda, S B <br/> <br/>Abstract: The photocatalyst BaCrO₄ has been utilized to photocatalytically degrade Azur B in presence of visible light. <span style="color: rgb(39, 36, 37);" lang="EN-GB">The disappearance of the dye has been monitored spectrophotometrically, followed pseudo-first order kinetics, according to the Langmuir–Hinshelwood model. The total degradation of dye was tested by determining the chemical oxygen demand. To optimize the reaction condition, the effects of various parameters like amount of semiconductor, <i style="">p</i>H, light intensity, dye concentration, oxidants such as H₂O₂ and K₂S₂O₈, electron acceptors like NaCl and Na₂CO₃, on the rate of photodegradation have been investigated. Both NaCl and Na₂CO₃<span style="color: rgb(39, 36, 37);" lang="EN-GB"> are found to retard the rate of photocatalytic degradation, whereas increase in the initial concentration of both H₂O₂ and K₂S₂O_8,increases the degradation rate. The degradation efficiency was found to be the substantially high at around neutral <i style="">p</i>H values. The complete degradation of the dye has been confirmed using UV spectrum analysis. A pertinent mechanism for the photocatalytic degradation has also been proposed. </span></span> <br/> <br/>Page(s): 1061-1065 http://nopr.niscair.res.in/handle/123456789/12478 Title: Enhanced activity of Au catalysts from extra-high surface area CeO₂ for CO oxidation <br/> <br/>Authors: Jin, Ling-Yun; Guo, Cun-Xia; Wang, Yue-Juan; Lu, Ji-Qing; Luo, Meng-Fei <br/> <br/>Abstract: A series of Au/CeO₂ catalysts has been prepared with CeO₂ of varying surface areas and tested for low-temperature CO oxidation. With a higher surface area support, the Au/CeO₂ catalysts show a higher catalytic activity for CO oxidation (0.175 mol_CO g_Au^-1 h^-1 at 0 °C). Higher oxygen vacancies provided by the formation of solid solution of Au_xCe_1-xO_2-_δ and higher CO chemisorption sites related to Au species are responsible for the enhanced activity. <br/> <br/>Page(s): 1056-1060 http://nopr.niscair.res.in/handle/123456789/12477 Title: Surface acidic properties of sulphated Fe₂O₃-TiO₂ <br/> <br/>Authors: Raj, K Joseph Antony; Prakash, M G; Shanmugam, R; Krishnamurthy, K R; Viswanathan, B <br/> <br/>Abstract: Mixed iron and titanium oxides with varying quantities of sulphate species have been prepared by sulphation of ilmenite followed by calcination. A combined approach involving DFT and DRIFT spectroscopy has been adopted to determine the appropriate structure for adsorption of pyridine on sulphated Fe₂O₃-TiO₂ (SFT). The DRIFT spectra obtained for pyridine adsorbed SFT samples show equal number of Brønsted and Lewis acid sites. The TG-DTG analysis reveals the greater affinity for water and hydroxyl groups on SFT. Evaluation of IR frequencies for various structures based on DFT demonstrates that the adsorption of water/hydroxyl groups on S and/or Fe leads to the conversion of Lewis acid sites into Brønsted acid sites. Investigation of Mulliken charges for Fe, Ti, S and N for the pyridine adsorbed SFT structures demonstrates the preferable adsorption of pyridine on sulphur rather than on Fe. <br/> <br/>Page(s): 1050-1055 http://nopr.niscair.res.in/handle/123456789/12476 Title: Organized media as redox catalysts on the reaction rate of Co^III-Fe^II redox couple <br/> <br/>Authors: Mukherjee, Mousumi; Mahapatra, Ambikesh <br/> <br/>Abstract: Micelles catalyze the [Co(NH3)5Cl](NO3)2 - Mohr’s salt redox reaction due to the binding of the substrates onto the micellar surface by non-coulombic and coulombic interactions. This binding increases the encounter probability, leading to a substantially accelerated reaction. The kinetic studies of the same redox reaction have also been carried out in the water pools of non-ionic reverse micelles of Triton X-100/1-butanol in n-heptane. The findings indicate that probably substrate solubilization sites in micelles and reverse micelles are the interfacial and Stern regions. The reaction rates decrease with the water-to-surfactant mole ratio. The correct selection of surfactant for micelle, size of reverse micellar water pool cavity, different additives and the catalyst connecting nanoparticles control the electron transfer reaction rate in solution. Copper-sol induced catalysis occurs due to the availability of a suitable surface which acts as a mediator for the electron-transfer reaction between [Co(NH3)5Cl](NO3)2 and Mohr’s salt. <br/> <br/>Page(s): 1043-1049