Department of Chemistry

Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

Lead-acid systems dominate the global market owing to simple technology, easy fabrication, availability, and mature recycling processes. However, the sulfation of negative lead electrodes in lead-acid batteries limits its performance to less than 1000 cycles in heavy-duty applications. Incorporating activated carbons, carbon nanotubes, graphite, and other allotropes of carbon and compositing carbon with metal oxides into the negative active material significantly improves the overall health of lead-acid batteries. Carbons play a vital role in advancing the properties of lead-acid batteries for various applications, including deep depth of discharge cycling, partial state-of-charge, and high-rate partial state-of-charge cycling. Therefore, lead-carbon hybrid batteries and supercapacitor systems have been developed to enhance energy-power density and cycle life. This review article provides an overview of lead-acid batteries and their lead-carbon systems, benefits, limitations, mitigation strategies, and mechanisms and provides an outlook. © 2023 Elsevier B.V.

World University root node

Journal of Power Sources

Lead-acid batteries and lead–carbon hybrid systems: A review

We have experimentally demonstrated conclusive evidence of solvent-to-chromophore excited-state proton transfer (ESPT) as a deactivation mechanism in a binary complex isolated in the gas phase. This was achieved by determining the energy barrier of the ESPT processes, qualitatively analysing the quantum tunnelling rates and evaluating the kinetic isotope effect. The 1 : 1 complexes of 2,2′-pyridylbenzimidazole (PBI) with H2O, D2O and NH3, produced in supersonic jet-cooled molecular beam, were characterised spectroscopically. The vibrational frequencies of the complexes in the S1 electronic state were recorded using a resonant two-colour two-photon ionization method coupled to a time-of-flight mass spectrometer set-up. In PBI-H2O, the ESPT energy barrier of 431 ± 10 cm−1 was measured using UV-UV hole-burning spectroscopy. The exact reaction pathway was experimentally determined via the isotopic substitution of the tunnelling-proton (in PBI-D2O) and by increasing the width of the proton-transfer barrier (in PBI-NH3). In both cases, the energy barriers were significantly increased to &gt;1030 cm−1 in PBI-D2O and to &gt;868 cm−1 in PBI-NH3. The heavy atom in PBI-D2O decreased the zero-point energy in the S1 state significantly, resulting in elevation of the energy barrier. Secondly, the solvent-to-chromophore proton tunnelling was found to decrease drastically upon deuterium substitution. In the PBI-NH3 complex, the solvent molecule formed preferential hydrogen bonding with the acidic (PBI)N-H group. This led to the formation of weak hydrogen bonding between ammonia and the pyridyl-N atom, thus increasing the proton-transfer barrier width (H2N-H⋯Npyridyl(PBI)). The above resulted in an increased barrier height and a decreased quantum tunnelling rate in the excited state. The experimental investigation, aided by computational investigations, demonstrated conclusive evidence of a novel deactivation channel for an electronically excited biologically relevant system. The variation observed for the energy barrier and the quantum tunnelling rate by substituting NH3 in place of H2O can be directly correlated with the drastically different photochemical and photophysical reactions of biomolecules under various microenvironments. © 2023 The Royal Society of Chemistry.

Physical Chemistry Chemical Physics

Excited-state deactivation via solvent-to-chromophore proton transfer in an isolated 1 : 1 molecular complex: experimental validation by measuring the energy barrier and kinetic isotope effect

A membrane-free low cost microfluidic fuel cell (μFFC) consisting a trident shaped channel is molded into a poly(dimethyl siloxane) block and Ni wires affixed therein that doubled up as the catalyst and electrical connectors. Streams of aqueous acidic solutions of formic acid as the anolyte (fuel), KMnO4 as the catholyte (oxidant) and an acid electrolyte, flown through the respective channels at a constant rate ensured laminar flow across the length of the channels, while being in contact with the Ni wires, thereby tapping its’ catalytic activity for good electrochemical performance. The effect of varying fuel or oxidant concentration on the μFFC performance is studied. In the chronopotentiometric mode, the high catalytic activity of Ni allows high currents of the order of 1.25 mA to be sustained by the cell, particularly when the surface is fresh, and this current drops when the deposition of Mn, K, and S occurs. A flow rate of 150 μL/min. is found to be optimal, as the highest open-circuit voltage (OCV) of 1.33 V is attained at this flow rate. While the cell performance is largely unaffected by formic acid concentration, but it is controlled by KMnO4 concentration. Higher oxidant concentrations yielded higher OCVs, due to more amount of the five-electron reaction, occurring at the cathode enhancing the charge separation and hence the OCV. DRT studies of the EIS data resolved two different time constants for the anodic and cathodic processes. The μFFC delivers a maximum power density of 2.1 mW/cm2 and a stable current of 3.5 mA/cm2 for more than 10 min. at 0.6 V, thus validating its deployment in a variety of applications like diagnostic devices and as an independent power supply for MEMS devices. © 2023 Elsevier B.V.

Department of Chemical Engineering

Journal of Electroanalytical Chemistry

Performance evaluation of HCOOH micro-fluidic fuel cell using Ni wire electrode

A bioinspired mimic for the stabilization of hydroperoxyflavin intermediate formation was designed and investigated for monooxygenase like catalytic properties. A suitable peptide appendage was covalently linked to the C7-position of the neutral isoalloxazine core to synthesize Fl-G, Fl-F, Fl-P, and Fl-βA analogues. While the presence and identity of the peptide appendage were found to be crucial for catalytic efficiency, corroborative observations were made from theoretical studies as well, supporting the precise conformational and accessibility requirements for the stabilization of the key hydroperoxyflavin intermediate. A simple yet elegant flavopeptide model (Fl-G) was found to achieve almost quantitative catalytic efficiency compared to the control flavin analogue without a peptide appendage. © 2023 The Royal Society of Chemistry

Organic and Biomolecular Chemistry

Stabilizing hydroperoxyflavin intermediate formation via a peptide appendage: a neutral flavoenzyme model

MXenes: From Discovery to Applications of Two-Dimensional Metal Carbides and Nitrides

<a href="https://www.scopus.com/record/display.uri?eid=2-s2.0-85162669619&amp;origin=resultslist&amp;sort=cp-f&amp;src=s&amp;st1=Kurra&amp;st2=Narendra&amp;nlo=1&amp;nlr=20&amp;nls=count-f&amp;sid=7985bd1bfd1598602ae85991ca541e58&amp;sot=anl&amp;sdt=aut&amp;sl=36&amp;s=AU-ID%28%22Kurra%2c+Narendra%22+35758727100%29&amp;relpos=51&amp;citeCnt=0&amp;searchTerm=">High-temperature behavior and surface chemistry of carbide MXenes studied by thermal analysis</a>

Organic materials with tunable redox properties have become versatile charge storage materials due to their abundant precursors and sustainability. Environmentally benign nature and recyclability make them attractive over other classes of electrode materials. This perspective provides prospects for organic materials such as conducting polymers, two-dimensional covalent organic frameworks (2D COFs), polyaromatic hydrocarbons and their hybrids towards the design of simultaneous high charge storage with high-rate capabilities. Non-diffusional redox processes give rise to pseudocapacitance, a key parameter that overcomes the sluggish ion diffusion kinetics. The emerging area of organic materials for electrochemical energy storage is expanding beyond metal and metal-ion based rechargeable batteries. All-organic based hybrid metal-ion capacitors turn out to be the futuristic choice for sustainable energy storage. The scope for exploiting supramolecular principles towards the rational design of molecular assemblies via non-covalent interactions is discussed. Advancement of inorganic-organic hybrid architectures for the design of hybrid energy storage devices for a sustainable future is highly desired. © 2023 The Royal Society of Chemistry.

Sustainable Energy and Fuels

Organic materials as charge hosts for pseudocapacitive energy storage

Nephrotic syndrome (NS) is classified based on morphological changes of glomeruli in biopsied kidney tissues evaluated by time-consuming microscopy methods. In contrast, we employed desorption electrospray ionization mass spectrometry (DESI-MS) directly on renal biopsy specimens obtained from 37 NS patients to rapidly differentiate lipid profiles of three prevalent forms of NS: IgA nephropathy (n = 9), membranous glomerulonephritis (n = 7), and lupus nephritis (n = 8), along with other types of glomerular diseases (n = 13). As we noted molecular heterogeneity in regularly spaced renal tissue regions, multiple sections from each biopsy specimen were collected, providing a total of 973 samples for investigation. Using multivariate analysis, we report differential expressions of glycerophospholipids, sphingolipids, and glycerolipids among the above four classes of NS kidneys, which were otherwise overlooked in several past studies correlating lipid abnormalities with glomerular diseases. We developed machine learning (ML) models with the top 100 features using the support vector machine, which enabled us to discriminate the concerned glomerular diseases with 100% overall accuracy in the training, validation, and holdout test set. This DESI-MS/ML-based tissue analysis can be completed in a few minutes, in sharp contrast to a daylong procedure followed in the conventional histopathology of NS. © 2023 American Chemical Society.

Journal of Proteome Research

Rapid Molecular Evaluation of Human Kidney Tissue Sections by In Situ Mass Spectrometry and Machine Learning to Classify the Nephrotic Syndrome

Electronic and vibrational spectroscopic studies of molecules are of crucial importance to characterizing a molecule and detecting the molecular species in different environments. In this review article, we summarized some important theoretical methods to calculate high-resolution electronic spectra and ro-vibrational states for small molecular systems with the inclusion of vibronic and ro-vibrational couplings, respectively. We have also reviewed a number of theoretical studies exploring some interesting organic chromophores like indole, isoalloxazine, transition metal trifluoride CoF3 and NiF3, and molecular ions like protonated rare gases and azido ions. These studies involve the calculation of spectroscopic features based on analytical potential energy surfaces (PESs) constructed using high-level ab initio energies. The topology of the PESs has been explored for these selected systems. The vibronic spectra and ro-vibrational states calculated using various theoretical methods and their comparison to available experimental results are reported in this review. © 2023 IOP Publishing Ltd.

Electronic Structure

High-resolution electronic and vibrational spectroscopy of small-to-medium sized molecules with ab initio potential energy surface

Catalytic valorization of methanol in organic synthesis and energy technologies is interesting and important for both fundamental research and industrial applications. In particular, its utilization as hydrogen, deuterium and methyl sources for selective reduction and deuteration reactions as well as to access N-methylated products is highly desirable and can be considered as a potential methodology for the amplification of transfer hydrogenation and C1 chemistry. Here, we report homogeneous Ru-MACHO complex catalyzed transfer hydrogenation of different functionalized compounds such as ketones, aldehydes, alkynes, alkenes, imines, azobenzenes, and nitro compounds as well as deoxygenation of N-oxide derivatives employing methanol as an affordable hydrogen donor and solvent. This Ru-based strategy has been proven to be very convenient for the deuteration process to synthesize advanced deuterium-labelled compounds, including the gram-scale synthesis of deuterated pharmaceuticals such as d-Cloperastine, d-Buclizine, d-Diphendyarmine, d-Modafinil, and d-Adrafinil using CD3OD. In addition, the application of methanol as a C1 source for the preparation of N-methylated products is showcased. Finally, kinetic and mechanistic investigations for this Ru-catalyzed transfer hydrogenation and deuteration protocols have been performed. © 2023

Journal of Catalysis

General and selective homogeneous Ru-catalyzed transfer hydrogenation, deuteration, and methylation of functional compounds using methanol

Hydrogenation of aldehydes with heterogeneous manganese catalysts is an appealing approach for producing alcohols. In this paper, we report a novel and robust MnO/PN-800 catalyst for the hydrogenation of versatile biomass-derived platform molecules in the presence of molecular hydrogen as a reductant. The effect of catalyst concentration, the operating hydrogen pressure, and the reaction temperature on the catalyst activity was investigated in detail. Under the mild reaction conditions, the full conversion of furfuraldehyde, 5-Methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde (5-HMF) to their corresponding alcohols was achieved without any by-product formation. Additionally, other aromatic aldehydes bearing fluoro, chloro, and nitro moieties were also tolerated. The fresh and spent MnO/PN-800 catalyst was thoroughly characterized using XPS, powder-XRD, HR-TEM, N2 adsorption-desorption, and Raman spectroscopy. Noteworthy, the MnO/PN-800 catalyst can be recovered by centrifugation and then reused directly in the subsequent hydrogenation reactions. Importantly the synthetic utility of this protocol up to ∼5 g-scale is realized. Finally, our novel MnO/PN-800 nanocatalyst was successfully employed for the direct synthesis of furfuryl alcohol in high yields from raw sugarcane bagasse. We believe that these findings will help to advance the manganese-catalyzed hydrogenation reactions. © 2022 Elsevier B.V.