Faculty Publications
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Item Hierarchical porous Batio3 nano-hexagons as a visible light photocatalyst(Science Publishing Corporation Inc ijet@sciencepubco.com, 2018) Bantawal, H.; Bhat, D.K.Hierarchical porous BaTiO3 nano-hexagons was synthesized via a simple hydrothermal route by using TiO2 and Ba(OH)2.8H2O as starting materials under alkaline environment and its photocatalytic activity was evaluated under visible light by taking methylene blue (MB) as a model pollutant. The prepared BaTiO3 was characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy dispersive X-rays analysis (EDX), high resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) analysis and diffused reflectance spectroscopy (DRS) techniques. It is noteworthy that the BaTiO3 nanohexagons exhibited significant photocatalytic activity towards the degradation of MB under visible light irradiation. This significant photocatalytic activity of BaTiO3 under visible light is mainly attributed to the special morphology and formation of Ti3+ defects. © 2018 Authors.Item Vanadium-doped BaTiO3 as high performance thermoelectric material: role of electronic structure engineering(Elsevier Ltd, 2020) Shenoy, U.S.; Bhat, D.K.It is well known that thermoelectric (TE) materials are the most sought-after ones to mitigate energy crisis. Development of an efficient non-toxic, economic, abundant, and stable TE material is quite difficult due to its complicated traits. BaTiO3, a perovskite material shows a tremendous potential as a TE material due to its highly tunable electronic structure. Herein, for the first time we report use of dopant to improve the Seebeck coefficient of BaTiO3. We used first-principles density functional theory calculations to study the effect of vanadium doping in BaTiO3, and for the first time, we report that V acts as a resonant dopant in BaTiO3. The study on effect of site occupancy reveals that V in Ba site distorts the density of states below the conduction band by introducing resonance level at the Fermi level. The transport property calculations based on Boltzmann's relation predicts V-doped BaTiO3 to be a potential TE material. The results also provide new insights into development of BaTiO3 as a multifunctional material. © 2020 Elsevier LtdItem Rhodium doping augments photocatalytic activity of barium titanate: Effect of electronic structure engineering(Royal Society of Chemistry, 2020) Bhat, D.K.; Bantawal, H.; Shenoy, U.S.Environmentally friendly BaTiO3 is emerging as a potential photocatalyst due to its tunable electronic structure. Although originally believed to be a poor photocatalyst due to its wide band gap, several strategies have been implemented to reduce its band gap. One such approach is doping, but this often leads to the formation of mid gap recombination centers and diminishes the efficiency of the material. In the present work, we study for the first time the effect of site occupancy of Rh on the electronic structure of BaTiO3. As the theoretical results reveal that if Rh occupies both Ba and Ti sites simultaneously it leads to the formation of mid gap states, an experimental approach is implemented to reduce the band gap of BaTiO3 while simultaneously avoiding the formation of recombination centers. The facile one pot hydrothermal approach reported here directs the Rh towards Ba sites leading to a decrease in the band gap due to the appearance of donor Rh3+ states, suppressing the formation of Rh4+ states. A promising photocatalytic activity of 96% degradation of methylene blue dye in 120 minutes was observed for the 0.5 Rh sample indicating the high efficiency of the material. © The Royal Society of Chemistry.Item Doped BaTiO3 cuboctahedral nanoparticles: Role of copper in photocatalytic degradation of dyes(Elsevier B.V., 2023) Uma, P.I.; Shenoy, U.S.; Bhat, D.K.The discovery of perovskite oxides as photocatalysts has opened unique possibilities for the degradation of pollutants such as dyes. In this work, we carry out both theoretical and experimental study for the design and preparation of copper doped BaTiO3. To begin with, First principles electronic structure calculations revealed the presence of additional levels at the top of the valence band after doping copper, which considerably decreased the band gap making the oxide visible light active. Later, single pot synthesis of copper doped BaTiO3 led to production of a material which was photocatalytically active in degrading both cationic and anionic dyes. From our work, we found that the photocatalyst 0.5 CuBTO decomposed 98.2% of methylene blue dye in 120 min and 99.4% of rose bengal dye within 45 min. Such high efficiency was attributed to the high surface area, appropriate band gap and low recombination rate of the charge carriers. © 2023Item Enhanced photoresponse and efficient charge transfer in porous graphene-BaTiO3 nanocomposite for high performance photocatalysis(Elsevier Ltd, 2023) Bhat, D.K.; Bantawal, H.; Uma, U.; Shenoy, U.S.Porous graphene-BaTiO3 (PGBT) nanocomposite was synthesized by a simple one pot solvothermal method and its photocatalytic activity was evaluated by studying its efficiency in degrading methylene blue (MB) dye under visible light. The combination of experimental and theoretical analysis revealed enhanced photocatalytic activity of the PGBT composite, which could be attributed to (i) the interaction of BaTiO3 nanoparticles with PG sheets via Ba–C bond, (ii) reduced band gap due to the introduction of hybridized states leading to increased absorption in visible range and (iii) large surface area which provides more active sites for the efficient adsorption of MB dye. The formation of Ba–C bond proved to be highly advantageous for the efficient transport of photogenerated charge carriers, thereby suppressing the recombination of charge carriers. The synthesized nanocomposite showed three times higher photodegradation efficiency compared to BaTiO3. In addition to this, the composite also showed an excellent cyclic stability indicating its suitability as an effective photocatalyst for the environmental remediation. © 2023 Elsevier B.V.Item Exploring the impact of modulation of electronic structure via doping in the realm of environmental applications(Elsevier B.V., 2025) Shenoy, U.S.; Amin, B.; Bhat, D.K.Engineering the electronic structure of a material is quite a fascinating field of study as it not only helps in improving the performance of the material but also helps us understand why a particular combination of elements exhibits the properties it does. Substitutional doping has been receiving increasing interest in the field of photocatalysis for boosting the performance of the material by tuning its crystal structure and electronic structure. In this study, we report the effect of site occupancy of silver in Ag doped BaTiO3. First principles density functional theory calculations highlight that the Ti site which is the preferred site in BaTiO3 for most of the dopants is not so preferred in the case of Ag doping for enhancing the photocatalytic activity. It also reveals the exceptional behavior of Ag where in it prevents the formation of mid gap recombination centers in the case of mixed occupancy. Doped samples synthesized through solvothermal approach with directed doping shows activity of 99.2 % and 99 % degradation of rose bengal and malachite green dyes in 40 and 50 min, respectively. © 2025