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Item Hydrogen storage on MgO supported TiMgn (n = 2–6) clusters: a first principle investigation(Elsevier, 2024-08) Bandyopadhyay, DebashisThe current study explores the potential of MgO-supported finite-sized TiMgn (n = 2–6) nanoclusters as hydrogen storage materials, employing density functional theory with a spin-polarized generalized gradient approximation (GGA). These systems' structural stability and electronic characteristics reveal that supported clusters offer superior hydrogen storage capabilities compared to their unassisted counterparts. Various parameters, including cluster-adsorption energy (Eads), hydrogen-adsorption energy in supported clusters (Eads-H), HOMO-LUMO gap, vertical ionization potential (VIP), vertical electron affinity (VEA), chemical potential (μ), and chemical hardness (ɳ) are computed. Substrate support notably enhances the thermodynamic stability and chemical reactivity of the TiMg5 cluster when contrasted with the bare TiMg5 cluster. Furthermore, a remarkable increase in the gravimetric hydrogen storage density, from 1.63 wt% for bare Mg5 clusters to 3.45 wt% for bare TiMg5 clusters, reaching 5.62 wt% in the supported TiMg5 cluster system is observed. These findings indicate the substrate-supported TiMg5 cluster as a promising candidate for hydrogen storage applications.Item Hydrogen storage in Ti doped 4-6-8 biphenylene (Ti.C468): Insights from density functional theory(Elsevier, 2024-08) Bandyopadhyay, DebashisHydrogen storage exploration in carbon-based materials is pivotal for advancing energy technologies. This study employs first-principles Density Functional Theory (DFT) calculations, utilizing the PBE functional with the VASP code, to investigate the 4-6-8 biphenylene (C468) and its derivatives, a distinctive 2D carbon structure. Both pristine C468 and its titanium-decorated variants (1TiC468 and 2TiC468) are analyzed. 1TiC468 and 2TiC468 exhibit maximum hydrogen molecule accommodation of up to 12 and 24, achieving gravimetric densities of 6.713 wt% and 11.188 wt%, respectively, with adsorption energies ranging from −0.132 eV/H2 to −0.399 eV/H2. These gravimetric values align with or surpass DOE guidelines. Additionally, comparative analysis indicates enhanced hydrogen adsorption due to Ti presence in C468. Molecular dynamics (MD) and phonon dispersion studies confirm the stability of mTiC468 (m = 1 and 2) systems at 300K. These findings underscore the potential of Ti-decorated C468 as hydrogen storage candidates, expanding the applications of carbon-based materials in energy storage.Item Insights of Ti-doping on the hydrogen adsorption properties of the 2D-BeN4 monolayer: A density functional investigation(Elsevier, 2025-02) Bandyopadhyay, DebashisWe examined the hydrogen storage properties of Ti-doped 2D-Beryllonitrene (2D-BeN4) using Density Functional Theory (DFT). Bader charge analysis revealed charge transfer from titanium to BeN4 and H2 molecules. TiBeN4 and 2Ti–BeN4 complexes showed Kubas interactions, allowing the binding of multiple hydrogen molecules with average adsorption energies between −0.360 eV/H2 and -0.371 eV/H2, and desorption temperatures of 460 K and 475 K respectively, meeting DOE standards. NEB studies indicated binding energies of −2.06 eV and −2.09 eV between Ti and BeN4 in TiBeN4 and 2Ti–BeN4 respectively, which are lower than the diffusion barrier energy, suggesting that there is no possibility of hoping of Ti atom from one hexagonal caped position to another equivalent position. Spin-polarized PDOS revealed induced magnetism in TiBeN4. Calculated adsorption isotherms (H2 uptake graphs) at various pressures align with DOE norms. The electronic structure analysis highlights Ti-doped BeN4 monolayers as promising materials for hydrogen storage applications.Item First-Principal Study of the Effect of Ti Doping on Hydrogenation of Mgn (N=2-8) Nanoclusters(SSRN, 2023-02) Bandyopadhyay, DebashisWe report the effect of single Ti atom doping Mgn (n=2-8) clusters on hydrogenation kinetics using density functional theory (DFT). During growth process, variations of different energetic parameters, such as binding energy, stability, etc., with the size of the clusters, Mg4 and TiMg5, are found as thermodynamically stable. From chemisorption energies in hydrogenated Mgn and TiMgn clusters, we have estimated the catalytic effect of Ti doping in Mgn clusters to improve the dose of hydrogen. It is found that the activation barrier reduces by about 32.8% after Ti doping, as evident from the IRC study. ELF mapping indicates that the Ti doping increase the reactive sites in the Mg5 cluster, and the TiMg5 can absorb extra hydrogen molecule to attain the average binding energy of Mg5-2H. So, Ti doping in the Mg5 cluster improves the hydrogenation process as well as the dose concentration because of its catalytic activitiesItem Insights into catalytic behavior of TiMgn (n=1–12) nanoclusters in hydrogen storage and dissociation process: A DFT investigation(Elsevier, 2022-03) Bandyopadhyay, DebashisThe present study reports the insight of the catalytic behavior of TiMgn (n = 1–12) nanoclusters in hydrogenation and dissociation reaction mechanism under density functional theory (DFT) investigation. From the variation of thermodynamic and chemical parameters during growth process of TiMgn, 18-electron TiMg7 cluster is found as the most stable with orbital sequence 1S21P61D10. However, after hydrogenation TiMg5 is found as the most efficient catalyst in hydrogenation and dissociation reaction. Following the calculated IRC path of the hydrogenation reaction process (H2+TiMg5→TiMg5–2H), it is found that the low activation barrier and reaction energy helps in hydrogenation-dissociation process; and also in the reduction of dehydrogenation temperature. Calculated ELF confirms that the dissociated hydrogen tends to localize on the outer surface of the TiMg5 cluster. The present investigation provides strong evidence of efficient catalytic behavior of TiMg5 in hydrogenation process. The findings are important for designing TiMgn based catalyst in hydrogen storage and dissociation reaction.