Faculty Publications
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Item Electronic structure engineering of tin telluride through co-doping of bismuth and indium for high performance thermoelectrics: A synergistic effect leading to a record high room temperature ZT in tin telluride(Royal Society of Chemistry, 2019) Shenoy, U.S.; Bhat, D.K.The ever increasing demand for alternative clean energy sources has led to intense research towards the optimization of thermoelectric performance of known systems. In this work, we engineer the electronic structure of SnTe by co-doping it with Bi and In. The co-doping not only results in the formation of two different resonance states and a reduced valence band offset, as in the case of previously reported co-doped SnTe, but also leads to opening of the band gap, which otherwise was closed in the case of Bi and In doped SnTe configurations, leading to suppression of bipolar diffusion. The synergistic action of all these effects leads to an increased Seebeck co-efficient throughout the temperature range and a ZTmax of ?1.32 at 840 K. This strategy of co-doping two different resonant dopants resulted in a record high room temperature ZT of ?0.25 at 300 K for SnTe based materials. This work suggests that appropriate combination of dopants to engineer the electronic structure of a material can lead to unpredictable results. © 2019 The Royal Society of Chemistry.Item Cobalt-doped LaFeO3 for photo-Fenton degradation of organic pollutants and visible-light-assisted water splitting(Springer, 2024) James, A.; Rodney, J.D.; Manojbabu, A.; Joshi, S.; Rao, L.; Badekai Ramachandra, B.R.; Udayashankar, N.K.The increasing demand for clean energy sources and the growing concerns about environmental pollution have led to a significant interest in developing efficient photocatalytic and photoelectrochemical systems. Here, we report the visible-light-induced photo-Fenton catalytic degradation of Methylene Blue (MB) dye over LaFeO3 and LaCo xFe1−xO3 (x = 0.01, 0.05, 0.1) catalysts synthesized via the facile combustion method. The LaCo0.01Fe0.99O3 has significantly enhanced the photo-Fenton catalytic efficiency of LaFeO3 from 67.75 to 93.85% for MB dye removal after 180 min of light irradiation. The rate constants calculated via the pseudo-first-order kinetics mechanism are found to be 0.00532/min for LaFeO3 and 0.01476/min for LaCo0.01Fe0.99O3, respectively. In addition, the most effective LaCo0.01Fe0.99O3 catalyst has demonstrated remarkable degradation performance towards Tetracycline (TC) and Methyl Orange (MO) dye with an efficacy of 93.81% and 69.67%, respectively, indicating its versatility. Further, the pristine and doped LaFeO3 were structurally optimized using DFT, and the computed band gaps were following the experimental data. Interestingly, the same catalyst can be employed as a light-induced electrocatalyst in addition to water treatment by taking advantage of its dual functionality. The LaCo0.01Fe0.99O3 catalyst achieved a benchmark current density of 10 mA/cm2 for H2 evolution at an overpotential of 297 mV vs. RHE which further improved to 190 mV vs. RHE under illumination. This work provides valuable insights on partial Co incorporation at the B-site of LaFeO3 for the development of visible-light-induced photocatalytic and electrocatalytic systems, which is hoped to contribute to the advancement of sustainable energy production and environmental remediation. © 2024, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Item Synthesis of BNiO3 Nanocomposites for Photocatalytic Hydrogen Production Applications(Springer, 2024) Choudhary, R.K.; Kumaraswamy, G.N.; Baitha, R.; Kumar, M.; Shekokar, S.R.; Kumar, A.; Hussain, M.H.; Kumar, P.The pursuit of sustainable and clean energy sources has prompted significant research efforts toward developing efficient photocatalytic materials for hydrogen production. In this study, we present a comprehensive review of the synthesis of BNiO3 nanocomposites and their potential application as efficient photocatalysts for hydrogen production. The synthesis of BNiO3 nanocomposites involves the integration of bismuth oxide (Bi2O3) and nickel oxide nanoparticles with boron nitride nanosheets. Various synthesis techniques have been employed to fabricate these nanocomposites, including sol–gel, hydrothermal, and co-precipitation methods. The choice of synthesis method significantly influences the nanocomposites' structural, morphological, and optical properties, thereby affecting their photocatalytic performance. The morphological characterization techniques, such as scanning electron microscopy, transmission electron microscopy, and X-ray diffraction, have been utilized to investigate the structural and morphological properties of BNiO3 nanocomposites. The photocatalytic activity of BNiO3 nanocomposites for hydrogen production has been extensively studied. The mechanism of hydrogen production involves the absorption of solar energy by the BNiO3 nanocomposites, followed by the generation of electron–hole pairs. This report provides valuable insights into the synthesis techniques, characterization methods, and photocatalytic performance of BNiO3 nanocomposites. Further research is warranted to optimize the synthesis parameters and explore novel strategies for enhancing the efficiency and stability of these nanocomposites, ultimately contributing to the development of sustainable energy solutions. © The Institution of Engineers (India) 2024.Item Growth of octahedral structured AgBiS2 single crystals and its insights on the high performance electrocatalytic hydrogen generation(Elsevier Ltd, 2024) Jauhar, R.O.M.; Ramachandran, K.; Deepapriya, S.; Joshi, S.; Ghfar, A.A.; Rao, L.; Badekai Ramachandra, B.R.; Udayashankar, N.K.; Vadivel, V.; Raji, R.; Kim, B.C.; Rodney, J.D.Given the enormous depletion of fossil fuels and growing environmental concerns, there is an immediate need to develop alternative and clean energy sources. Hydrogen (H2), recognized for its cleanliness and renewability, is poised to meet future energy requirements. Consequently, ongoing research is focused on the development of electro-active, durable, and cost-effective catalysts to replace expensive noble metal-based electrocatalysts. In this study, microscale AgBiS2 chalcogenide derived from a single crystal is reported as promising electrocatalysts for the Hydrogen Evolution Reaction (HER) with a remarkably low overpotential. The physico-chemical characterization of the AgBiS2 catalyst has been investigated using various analytical techniques. The synthesized AgBiS2 catalyst exhibits excellent HER activity, manifesting a low overpotential of 86 mV at a current density of 10 mA cm−2 and a Tafel slope of 44 mV dec−1, along with superior stability even after 24 h in HER at a very high current density. The developed AgBiS2 also showcased stable production when subjected to a two-electrode system. The enhanced alkaline HER activity of AgBiS2 can be attributed to its phase purity, high crystallinity, and the presence of high active sites. The observed high electrochemical performance and stability position AgBiS2 as a potential electrocatalyst for the hydrogen evolution reaction. This finding holds significant promise in the quest for efficient, durable, and economically viable catalysts to drive the shift towards clean and renewable energy sources. © 2024 Hydrogen Energy Publications LLCItem Exploring MIL-101 (Cr) and Its Polymeric Composites as Potential Adsorbents for Volatile Iodine from Nuclear Off-gas: A Detailed Experimental and Computational Study(American Chemical Society, 2025) Kolay, S.; Kancharlapalli, S.; Samanta, S.; Muhiuddin, M.; Jha, P.; Pagare, A.; Mishra, R.Owing to the rapid growth of nuclear energy as a sustainable, affordable, and clean energy source, the entrapment of radioactive iodine released from the nuclear off-gas stream is considered a vital concern. We view MOFs as potential futuristic adsorbents for this remedy. Herein, we examined the gravimetric iodine adsorption characteristics of radiation and chemically stable MIL-101(Cr) and its polymeric composites with variation of temperatures. The saturation adsorption capacity shown by pristine MIL-101(Cr) is 4.1 g I2 g-1, and the saturation capacity of composites varies based on MIL-101(Cr)’s concentrations. MIL-101(Cr)@PES 2:1 shows an uptake capacity of 2.1 g I2 /gbead, which is ? 350% superior to the reported HKUST-1@PES and ?150% higher compared to MOF-808@PVDF0.7. Based on various spectroscopic studies and DFT calculations, probable host-guest interactions leading to enhanced I2 adsorption have been elucidated. The open Cr metal site acts as the initial adsorption site for I2 that gets converted into iodide and afterward to higher polyiodide through the transfer of charge from the host matrix. These findings suggest that MIL-101(Cr) can be considered one of the potential alternate adsorbents for radioactive iodine. © 2025 American Chemical Society.