Deep neural network analysis of nanoparticle ordering to identify defects in layered carbon materials

Chemical Science, Journal Year: 2021, Volume and Issue: 12(21), P. 7428 - 7441

Published: Jan. 1, 2021

Defectiveness of carbon material surface is a key issue for many applications. Pd-nanoparticle SEM imaging was used to highlight “hidden” defects and analyzed by neural networks solve order/disorder classification defect segmentation tasks.

Language: Английский

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Structure and Stability of the Ionic Liquid Clusters [EMIM]_n[BF₄]_n+1^– (n = 1–9): Implications for Electrochemical Separations

The Journal of Physical Chemistry Letters, Journal Year: 2020, Volume and Issue: 11(16), P. 6844 - 6851

Published: July 22, 2020

Precise functionalization of electrodes with size-selected ionic liquid (IL) clusters may improve the application ILs in electrochemical separations. Herein we report our combined experimental and theoretical investigation IL 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM]n[BF4]n+1– (n = 1–9) demonstrate their selectivity efficiency toward targeted adsorption ions from solution. The structures energies clusters, predicted global optimization, agree help interpret ion abundances stabilities measured by high-mass-resolution electrospray ionization mass spectrometry collision-induced dissociation experiments. [EMIM][BF4]2– cluster, which was identified as most stable selectively soft-landed onto a working electrode. Electrochemical impedance spectroscopy revealed lower charge transfer resistance on electrode containing compared an prepared drop-casting solution full range clusters. Our findings indicate that specific be used to increase separations lowering overpotentials involved.

Language: Английский

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Geometric evolution, electronic structure, and vibrational properties of ScGe_n⁻ (n = 6–17) anion clusters: A DFT insight

International Journal of Quantum Chemistry, Journal Year: 2022, Volume and Issue: 122(24)

Published: Aug. 17, 2022

Abstract A comparison of theoretical and experimental properties is the most effective strategy for determining global minimum (GM) because there no method to directly test GM structure clusters by now. The molecular electronic structures Sc‐doped germanium anion were explored via quantum chemistry calculations using mPW2PLYP scheme unprejudiced structural searching technique ABCluster. Isomers are determined ABCluster searches, followed reoptimization a great number candidate geometries. simulated photoelectron spectra match with those measured in experiment, suggesting that current stable existence experiment. evolution modes appear as follows: cluster size n increases, growth patterns from Sc‐linked geometry ( = 10, 11) which Sc atom acts linker (Sc connects two Ge sub‐clusters) Sc‐encapsulated form 13–17) settled core Ge‐cage framework. Besides, including stability, HOMO‐LUMO gap, charge transfer, IR, Raman, UV–Vis calculated. Raman red‐shifted configurations. analyses revealed ScGe 16 − nanocluster could be suitable building block further development potential optoelectronic materials such solar cell.

Language: Английский

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Computational description of surface hydride phases on Pt(111) electrodes

The Journal of Chemical Physics, Journal Year: 2022, Volume and Issue: 158(1)

Published: Dec. 7, 2022

Surface platinum hydride structures may exist and play a potentially important role during electrocatalysis cathodic corrosion of Pt(111). Earlier work on hydrides suggests that Pt form clusters with multiple equivalents hydrogen. Here, using thermodynamic methods density functional theory, we compared several surface The contain monolayers hydrogen in or near the layer. these bind subsurface reconstruct both set initial configurations resulting (meta)stable structures. Multilayer stable share one monolayer H stacking between top two layers. structure containing (MLs) is formed at -0.29 V vs normal electrode, locally respect to similar densities, binds neutrally. Structures 3 4 ML -0.36 -0.44 V, respectively, which correspond reasonably well experimental onset potential For configuration, layer reconstructed by interstitial atoms well-ordered surrounded four, five, six roughly square-planar octahedral coordination patterns. Our provides insight into operando state low-potential reduction reactions Pt(111) shows plausible precursor for corrosion.

Language: Английский

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Structural evolution and electronic properties of cerium doped germanium anionic nanocluster CeGe_n⁻ (n = 5–17): Theoretical investigation

International Journal of Quantum Chemistry, Journal Year: 2023, Volume and Issue: 124(1)

Published: Dec. 15, 2023

Abstract The rare earth element doped germanium cluster represents a fundamental nanomaterial and exhibits potential in next‐generation industrial electronic nanodevices applied semiconductors. Herein, the cerium‐doped anionic nanocluster CeGe n − ( = 5–17) has been comprehensively investigated by double hybrid density functional theory of mPW2PLYP associated with unbiased global searching technique artificial bee colony algorithm. cluster's growth pattern undergoes three stages: 5–9 replaced structure, 10–15 linked ≥ 16 forming Ce‐encapsulated Ge inner cage motif. clusters' PES, IR, Raman spectra were simulated, their HOMO‐LUMO gap, magnetism, charge transfer, relative stability predicted. These theoretical values can serve as reference for future experiments to some extent. Moreover, special D 2 d symmetry geometry leads higher preferred energy making it an ideal candidate further studies on its aromaticity, UV–vis spectra, chemical bonding characteristics. In summary, excellent optical activity that be potentially employed building block development optoelectronic materials.

Language: Английский

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