http://nopr.niscpr.res.in/handle/123456789/40900 Fri, 09 Oct 2026 16:29:34 GMT 2026-10-09T16:29:34Z http://nopr.niscpr.res.in/handle/123456789/40911 Title: On the current status of the mechanistic aspects of photocatalytic reduction of carbon dioxide Authors: Narayanan, Hariprasad; Nair, M V Harindranathan; Viswanathan, Balasubramanian Abstract: Photocatalytic reduction of carbon dioxide, one of the pathways involved in the carbon dioxide conversion process, has been receiving significant attention from the scientific community in the last four decades. Nevertheless, the mechanism of carbon dioxide reduction is still unclear and the information available is not sufficient for developing it into large scale applications, possibly because of the invariable hurdles associated with the reduction process. The reductive photocatalytic conversion of CO₂ involves all the redox reactions occurring at the interface of the semiconductor such as water splitting, hydrogen evolution, oxygen evolution, photo-oxidation reactions and reactions of radical intermediates. The overall product yield is highly dependent on the extent of these competing reactions. Herein, we discuss our perceptions and current status of the interface reactions and their involvement in the fundamental mechanistic aspects of the photocatalytic conversion of CO₂. Page(s): 251-269 Wed, 01 Mar 2017 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/40911 2017-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/40910 Title: Photocatalytic and DC conductivity studies of proton exchanged KAl_0.33W_1.67O₆ and its application in Pb²⁺ removal Authors: Srinivas, M; Ravi, G; Kumar, P Vijaya; Reddy, CH Sudhakar; Sreenu, K; Guje, Ravinder; Vithal, M Abstract: The proton exchanged metal oxide of composition HAl_0.33Te_1.67O₆ (HAW) is synthesized by ion exchange method at room temperature and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-vis diffuse reflectance spectroscopy. Presence of water content in the HAW has been examined by thermogravimetric analysis. Conductivity and photocatalytic properties of HAW are compared with those of its parent KAl_0.33W_1.67O₆ (KAW). HAl_0.33W_1.67O₆ shows higher conductivity and photocatalytic activity for the degradation of methyl blue and Rhodamine B under visible light irradiation. Participation of hydroxyl radicals in the photocatalytic dye degradation has been investigated by photoluminescence studies using terephthalic acid as probe. The removal of Pb²⁺ from an aqueous solution of Pb(NO₃)₂ using pristine KAl_0.33W_1.67O₆ is also reported. Page(s): 270-277 Wed, 01 Mar 2017 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/40910 2017-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/40909 Title: Surfactant assisted synthesis of cobalt doped titania nanomaterial: Characterization and its applications in photocatalysis and anti-bacterial activity Authors: Chekuri, Radha Devi; Tirukkovalluri, Siva Rao Abstract: The synthesis of 0.5 wt. % cobalt doped titania nanomaterial (Co²⁺-TiO₂) assisted by sodium dodecyl sulfate anionic surfactant by sol-gel method is reported. The synthesized catalysts are characterized by XRD, UV-vis DRS, FT-IR, BET, TEM, SEM and XPS analysis. XRD results show that all the catalysts are in anatase phase. UV-vis DRS studies indicate that decrease in band gap of TiO₂ is due to doping of Co²⁺. FT-IR studies indicate the insertion of Co²⁺ into TiO₂lattice as a substitutional dopant. BET analysis shows an increase in surface area of the catalyst. From SEM and TEM analysis, change in the morphology of the particles with reduced particle size is observed. XPS studies confirm the presence of Co²⁺along with Ti and O. The photocatalytic efficiency of the catalyst has been evaluated by degradation of methyl red under visible light irradiation at various reaction parameters. The antibacterial activity of the catalyst against <em>Escherichia</em> <em>coli</em> has also been investigated. Page(s): 278-286 Wed, 01 Mar 2017 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/40909 2017-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/40908 Title: Combined effect of adsorbent chitosan and photosensitizer polypyrrole in ternary chitosan-polypyrrole-TiO₂ photocatalyst leading to visible light activity and superior functionality Authors: Murugan, C; Subramanian, E Abstract: The combined effect of the components in the ternary chitosan-polypyrrole-TiO₂ (Chit-Ppy-TiO₂) photocatalytic system has been investigated. The role of each component in this catalyst is validated by the visible light degradation of the model dye methylene blue. The reaction parameters, viz., amount of catalyst, dye concentration, oxidant concentration and temperature are studied in detail. The ternary system exhibits greater activity when compared to both the single and binary component catalysts (chitosan-TiO₂ and polypyrrole-TiO₂). The superior functionality of Chit-Ppy-TiO₂ (1:1:100 wt ratio) originates from the combined effect of greater dye adsorption of chitosan, visible light sensitization of polypyrrole and the catalytic functionality of TiO₂. The ternary photocatalyst is recyclable even after fourth  run without appreciable loss in its activity. Page(s): 287-296 Wed, 01 Mar 2017 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/40908 2017-03-01T00:00:00Z