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  • Article

    Electronic, optical, and thermoelectric characteristics of (Ae)xFBiS2 (Ae=Sr, Ba, and x=1.7) layered materials useful in optical modulator devices

    (Elsevier BV, 2024-02-22) Khan, W.; Kushwaha, A. K.; Al-Amer, R.; Alanazi, Nadyah; Alqahtani, H. R.; Al-Qaisi, Samah; Faizan, Muhammad; Haq, Bakhtiar Ul; Laref, A.; Alghamdi, Eman A.; Nya, Fridolin Tchangnwa; Amine Monir, Mohammed El; Chowdhury, Shahariar; Department of Physics, Bacha Khan University, Charsada, Pakistan; Department of Physics, K.N. Govt. P.G. College, Gyanpur, Bhadohi-221304 (U.P.), India; Department of Physics, K.N. Govt. P.G. College, Gyanpur, Bhadohi, 221304, U.P., India; Department of Physics and Astronomy, College of Science, King Saud University, Riyadh, 11451 King Saudi Arabia; Palestinian Ministry of Education and Higher Education, Nablus, Palestine; College of Materials Science and Engineering Jilin University, Changchun, China; Faculty of Science Education, Jeju National University, Jeju, 63243, Republic of Korea; Advanced Functional Materials & Optoelectronics Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia; University of Maroua, High national college of technology, Department of Energy and Environment; University of Maroua, Faculty of Science, Department of Physics, Materials Science Laboratory, P.O. Box 814, Maroua, Cameroon; Faculty of the Exact Sciences, Mustapha Stambouli University of Mascara, B.P. 305, 29000 Mascara, Algeria; Faculty of Environmental Management, Prince of Songkla University, Songkhla 90110, Thailand; Environmental Assessment and Technology for Hazardous Waste Management Research Centre, Faculty of Environmental Management, Prince of Songkla University, Songkhla 90110, Thailand

    The recent discovery of superconductivity behavior in the mother BiS2-layered compounds has captivated the attention of several physicists. The crystal structure of superconductors with alternate layers of BiS2 is homologous to that of cuprates and Fe-based superconductors. The full-potential linearized augmented plane-wave (FP-LAPW) technique was utilized to investigate the electronic structures and density of states in the vicinity of the Fermi energy of SrFBiS2 and BaFBiS2 compounds under the electron carriers doping. The introduction of electron doping (carries doping) reveals that the host compounds SrFBiS2 and BaFBiS2 exhibit features indicative of superconductivity. This carrier doping of SrFBiS2 and BaFBiS2 compounds (electron-doped) has a significant impact on the lowest conduction states near the Fermi level for the emergence of the superconducting aspect. The electron doping modifies and induces changes in the electronic structures with superconducting behavior in (Ae)1.7FBiS2(Ae=Sr,Ba) compounds. A Fermi surface nesting occurred under the modification of electrons (carriers) doping in the host compounds SrFBiS2 and BaFBiS2. Furthermore, the optical characteristics of the carrier-doped SrFBiS2 and BaFBiS2 compounds are simulated. Due to the anisotropic behavior, the optical properties of these materials based on BiS2 demonstrate a pronounced polarization dependency. The starting point at zero photon energy in the infrared region is elucidated by considering the Drude features in the optical conductivity spectra of SrFBiS2 and BaFBiS2 compounds, when the electron carriers doping is applied. It was clearly noticed that the spin-orbit coupling (SOC) influences the electronic band structures, density of states, Femi surface, and optical features because of the heavy Bismuth atom, which may disclose fascinating aspects. Further, we conducted simulations to assess the thermoelectric properties of these mother compounds. The two BiS2-layered compounds could be suitable for practical thermoelectric purposes and are highlighted through assessment of electrical conductivity, thermal conductivity, Seebeck coefficient, and power factor. As a result, we propose that the mechanisms of superconducting behavior in BiS2 family may pave new avenues for investigating the field of unconventional superconductivity. It may also provide new insights into the origin of high-Tc superconductivity nature.

  • Article

    The dynamic adsorption affinity of ligands is a surrogate for the passivation of surface defects

    (Springer Science and Business Media LLC, 2024-03-06) Xu, Jian; Maxwell, Aidan; Song, Zhaoning; Bati, Abdulaziz S. R.; Chen, Hao; Li, Chongwen; Park, So Min; Yan, Yanfa; Chen, Bin; Sargent, Edward H.; Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4, Canada; Department of Physics and Astronomy, and Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606, USA.; Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208, USA.; Department of Electrical and Computer Engineering, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208, USA

    Surface defects in semiconducting materials, though they have been widely studied, remain a prominent source of loss in optoelectronic devices; here we sought a new angle of approach, looking into the dynamic roles played by surface defects under atmospheric stressors and their chemical passivants in the lifetime of optoelectronic materials. We find that surface defects possess properties distinct from those of bulk defects. ab initio molecular dynamics simulations reveal a previously overlooked reversible degradation mechanism mediated by hydrogen vacancies. We find that dynamic surface adsorption affinity (DAA) relative to surface treatment ligands is a surrogate for passivation efficacy, a more strongly-correlated feature than is the static binding strength emphasized in prior reports. This guides us to design targeted passivator ligands with high molecular polarity: for example, 4-aminobutylphosphonic acid exhibits strong DAA and provides defect passivation applicable to a range of perovskite compositions, including suppressed hydrogen vacancy formation, enhanced photovoltaic performances and operational stability in perovskite solar cells.

  • Article

    Machine learning-based discovery of molecular descriptors that control polymer gas permeation

    (Elsevier BV, 2024-03) Shastry, Tejus; Basdogan, Yasemin; Wang, Zhen Gang; Kumar, Sanat K.; Carbone, Matthew R.; Department of Chemical Engineering, Columbia University, New York, New York 10027, USA; Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125, USA; Computational Science Initiative, Brookhaven National Laboratory, Upton, New York 11973, USA

    While machine learning has found increasing use in predicting the properties of polymeric materials with only a knowledge of chain architecture, determining the molecular factors underpinning properties (“interpretable AI”) has remained less well explored. We show that encoding chain chemistry in commonly employed formats, e.g., binary-valued fingerprints, leads to uniqueness issues during the hashing process to save storage space. This is because the hashing algorithm can map several chemical moieties into the same bit. These issues carry over into the ML algorithms, especially for “inverse” design and interpretable AI, and cannot be avoided by changing the length of the fingerprint. Using MACCS key featurizations of monomer repeats resolves some of these issues, and we show that a few substructures consistently appear in top features for maximizing permeability across several gases and ML models. These are carbon–carbon double bonds (as in polyacetylenes) especially when they are associated with methyl groups (found in branching architectures). These results, derived from the limited data set of ∼500 polymers with experimental gas permeation data, are in agreement with physical insight and thus provide a robust foundation which could further enable study of these material classes through detailed experiments and simulations.

  • Article

    Ab initio molecular dynamics of solvation effects and reactivity at the interface between water and ascorbic acid covered anatase TiO2 (101)

    (Wiley, 2024-01-10) Ritacco, Ida; Gatta, Gianluca; Caporaso, Lucia; Farnesi Camellone, Matteo; Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, via Giovanni Paolo II 132, 84084, Fisciano, Salerno, Italy; Dipartimento di Medicina di Precisione Divisione di Radiologia, Università della Campania Luigi Vanvitelli, Napoli, Italia, 80131; CNR-IOM, Consiglio Nazionale delle Ricerche –, Istituto Officina dei Materiali, c/o SISSA, 34136, Trieste, Italy

    In this work, we present a detailed study of the interaction between ascorbic acid (L-asc) and anatase TiO2 (101) surface both in gas phase and in contact with water by using density functional theory and ab initio molecular dynamics simulations. In gas phase, L-asc strongly binds the TiO2(101) surface as a dianion (L-asc2−), adopting a bridging bidentate coordination mode (BB), with the two acid protons transferred to two surface 2-fold bridging oxygens (O2c). AIMD simulations show that the interaction between the organic ligand and the anatase surface is stable and comparable to the vacuum one despite the possible solvent effects and/or possible structural distortions of the ligand. In addition, during the AIMD simulations hydroxylation phenomena occur forming transient H3O+ ions at the solid-liquid interface. For the first time, our results provide insight into the role of the ascorbic acid on the electronic properties of the TiO2 (101), the influence of the water environment on the ligand-surface interaction and the nature of the solid-liquid interface.

  • Article

    Use of hybrid molecular simulation techniques for systematic analysis of polyphenols as promising therapeutic agent against SARS-CoV-2

    (Elsevier BV, 2024-02-08) Muhammad, Shabbir; UrRehman, Shafiq; Zia, Maimoona; Bibi, Shamsa; Tousif, Muhammad Imran; Hussain, Aftab; Belali, Tareg M.; Chaudhry, Aijaz Rasool; aDepartment of Chemistry, College of Science, King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia; bDepartment of Chemistry, University of Agriculture Faisalabad, Faisalabad 38000, Pakistan; cDepartment of Chemistry, Division of Science and Technology, University of Education, 54770 Lahore, Pakistan; dUniversity of Punjab, Lahore, Pakistan; eFaculty of Applied Medical Sciences, University of Bisha, 255, Al Nakhil, Bisha 67714, Saudi Arabia; fDepartment of Physics, College of Science, University of Bisha, Bisha 61922, P.O. Box 551, Saudi Arabia

    In our current study, we systematically report the four phenol classes via three-layer in silico screening approaches consisting of quantum chemical methods, molecular docking and molecular dynamics simulations. We studied the interactions of main protease (Mpro) and Nsp9 proteins of SARS-CoV-2 with four classes of polyphenolic compounds, where both proteins are crucial for virus replication. The phenols are extensively reported for medicinal applications, as these are antioxidants, anti-parasitic, anti-viral, anti-diabetic and anti-inflammatory compounds. Initial molecular docking study shows that among forty phenolic compounds the L9, L17, L26 and, L32 reveal the best binding energies with Mpro protein. Their values of docking score in terms of binding energy with Mpro protein is ranging from -5.7 to -6.8 kcal.mol−1. While on the other hands, L8, L11, L22 and, L34 exhibit the best docking scores with Nsp9 protein, which are ranging from -5.8 to -6.8 kcal.mol−1. Additionally, the lead compounds (ligands) were studied by quantum chemical methods for their optimized or the lowest energy structures, electronic properties, frontier molecular orbitals (FMOs) as well as molecular electrostatic potentials (MEPs). The global chemical descriptors are also calculated to explain the global reactivity trend for the lead compounds. To mimic the aqueous like environment, we added ions according to the electrostatic potential of the macromolecule, water molecules are being added to create physiologically relevant environment for studying biological molecules. Proteins, nucleic acids, and other biomolecules are typically surrounded by water molecules in biological systems. The addition of water molecules in MD simulations may provide a more accurate representation of their natural environment. The molecular dynamics simulations are performed for the complexes of best-docked lead compounds and for both proteins (Mpro and, Nsp9) over multiple replicate trajectories of 320 ns. The flexibility and stability behavior of the lead compounds in terms of RMSD and RMSF plots are analyzed through MD simulations results. The binding free energy of the best-docked lead compounds with both proteins in terms of Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) analysis are calculated, which are found as -8.79 and -3.97 kcal.mol−1 for Mpro-L32 and Nsp9-L8 complexes, respectively. The pharmacokinetic analysis of the lead compounds are also performed to disclose their ADME (absorption, distribution, metabolism, and excretion) and toxic character using online server pkCSM. This allowed for a comprehensive understanding of how these compounds would behave in the organism, specifically focusing on their ADME properties. We believe that the current study can evoke the interest of scientific community by providing fundamental insights, which will ultimately lead in-vivo and in-vitro analysis to assess the studied phenolic therapeutic inhibitors against the SARS-CoV-2.