http://localhost:8080/xmlui/handle/123456789/4150 Research articles authored by NIIST researchers published in 2023 2026-04-08T08:47:02Z http://localhost:8080/xmlui/handle/123456789/4869 Title: Polycyclic Aromatic Hydrocarbons as Anode Materials in Lithium-Ion Batteries: A DFT Study Authors: Ramya, P K; Suresh, C H Abstract: The structure and energetics of the interactive behavior of Li+ and Li with polycyclic aromatic hydrocarbons (PAHs) have been studied at the wB97XD/6-311G(d,p) level of DFT. The electron distribution in the PAHs, analyzed using the topology of the molecular electrostatic potential (MESP), led to the categorization of their aromatic rings into five types, viz Rs, Rn, Rd, Rb, and Re. Among the different rings, sextet-type Rs and naphthalene-type Rn rings showed the highest interaction with Li+. The change in MESP at the nucleus of Li+ (ΔVLi+) due to the formation of the complex Li+...PAH is found to be proportional to the adsorption energy (E1). In Li...PAH, the spin density on Li is close to zero, suggesting the formation of Li+...PAH•− due to the electron transfer from Li to PAH. The adsorption energy (E2) for Li...PAH does not correlate with the change in MESP at the nucleus of Li, whereas the dissociation energy (E3) of Li+...PAH•− to yield Li+ and PAH•− correlates well with the MESP data, ΔVLi. The study confirms that the change in MESP at the nucleus of Li+ due to complex formation gives a quantitative measure of the electronic effect of the cation−π binding. The cell potential (Vcell) is predicted for the lithium ion battery (LIB) using the Li+...PAH and Li...PAH adsorption energies. On the basis of the Vcell data, “carbon nanoflake”-type systems, viz coronene, circumbiphenyl, C42H16, and C50H18 are suggested as good anode materials for LIBs. 2023-03-13T00:00:00Z http://localhost:8080/xmlui/handle/123456789/4736 Title: Waste-Derived Fuels and Renewable Chemicals for Bioeconomy Promotion: A Sustainable Approach Authors: Narisetty, V; Reshmy, R; Maitra, S; Tarafdar, A; Alphy, M P; Naresh Kumar, A; Madhavan, A; Sirohi, R; Awasthi, M K; Sindhu, R; Varjani, S; Binod, P Abstract: Bio-based fuels and chemicals through the biorefinery approach has gained significant interest as an alternative platform for the petroleum-derived processes as these biobased processes are noticed to have positive environmental and societal impacts. Decades of research was involved in understanding the diversity of microorganisms in different habitats that could synthesize various secondary metabolites that have functional potential as fuels, chemicals, nutraceuticals, food ingredients, and many more. Later, due to the substrate-related process economics, the diverse low-value, high-carbon feedstocks like lignocellulosic biomass, industrial byproducts, and waste streams were investigated to have greater potential. Among them, municipal solid wastes can be used as the source of substrates for the production of commercially viable gaseous and liquid fuels, as well as short-chain fattyacids and carboxylic acids. In this work, technologies and processes demanding the production of value-added products were explained in detail to understand and inculcate the value of municipal solid wastes and the economy, and it can provide to the biorefinery aspect. 2023-03-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/4727 Title: Innovative Transformation and Valorisation of Red Mill Scale Waste into Ferroalloys: Carbothermic Reduction in the Presence of Alumina Authors: Khanna, R; Konyukhov, Y; Li, K; Jayasankar, K; Maslennikov, N; Zinoveev, D; Kargin, J; Burmistrov, I; Leybo, D; Kravchenko, M; Mukherjee, P S Abstract: Primary and secondary mill scales (MSs) are waste products produced by the surface oxidation of steel during the hot (800 to 1200 °C) rolling process in downstream steelmaking. While the primary MS is comprised of FeO, Fe3O4, and Fe2O3 in a range of proportions, the secondary MS primarily contain red ferric oxide (Fe2O3) (red MS). We report a novel route for extracting iron from red MS and transforming it into ferro-aluminium alloys using carbothermic reduction in the presence of alumina. The red MS powder was blended with high-purity alumina (Al2O3) and synthetic graphite (C) in a range of proportions. The carbothermic reduction of red MS-Al2O3-C blends was carried out at 1450 °C and 1550 °C under an argon atmosphere for 30 min and then furnace-cooled. The red MS was completely reduced to iron at these temperatures with reduced iron distributed around the matrix as small droplets. However, the addition of alumina unexpectedly resulted in a significant increase in the number and sizes of iron droplets generated, much higher reactivity, and the formation of ferrous alloys. A small amount of alumina reduction into metallic aluminium was also observed at 1450 °C. There is an urgent need to identify the true potential of industrial waste and the materials within it. This study showed that red MS is a valuable material source that could be transformed into ferro-aluminium alloys. These alloys find application in a range of industrial sectors such as construction, automotive, infrastructure, etc. 2023-12-13T00:00:00Z http://localhost:8080/xmlui/handle/123456789/4726 Title: Blue emitting exciplex for yellow and white organic light-emitting diodes Authors: Rajeev, K; Vipin, C K; Sajeev, A K; Shukla, A; McGregor, S K M; Lo, S C; Namdas, E B; Narayanan Unni, K N Abstract: White organic light-emitting diodes (WOLEDs) have several desirable features, but their commercialization is hindered by the poor stability of blue light emitters and high production costs due to complicated device structures. Herein, we investigate a standard blue emitting hole transporting material (HTM) N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine (NPB) and its exciplex emission upon combining with a suitable electron transporting material (ETM), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ). Blue and yellow OLEDs with simple device structures are developed by using a blend layer, NPB:TAZ, as a blue emitter as well as a host for yellow phosphorescent dopant iridium (III) bis(4-phenylthieno[3,2-c]pyridinato-N,C2')acetylacetonate (PO-01). Strategic device design then exploits the ambipolar charge transport properties of tetracene as a spacer layer to connect these blue and yellow emitting units. The tetracene-linked device demonstrates more promising results compared to those using a conventional charge generation layer (CGL). Judicious choice of the spacer prevents exciton diffusion from the blue emitter unit, yet facilitates charge carrier transport to the yellow emitter unit to enable additional exciplex formation. This complementary behavior of the spacer improves the blue emission properties concomitantly yielding reasonable yellow emission. The overall white light emission properties are enhanced, achieving CIE coordinates (0.36, 0.39) and color temperature (4643 K) similar to daylight. Employing intermolecular exciplex emission in OLEDs simplifies the device architecture via its dual functionality as a host and as an emitter. 2023-12-14T00:00:00Z