bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anode-Free Sodium Ion Batteries: Effect of Pressure on Sodium Plating on Copper
Authors: Willow Ashley , Hussein Haytham E.M. , Margadonna Serena 
Published: July 2022

Sodium ion anode-free battery technology puts extra emphasis on high plating and stripping efficiency of sodium metal at the anode surface, due to the lack of an excess of the transporting ion. Recent studies have shown the importance of strict control of water content in enabling efficient plating and stripping of sodium on copper in the 1M NaPF6 in diglyme electrolyte[1]. We have achieved promising results at coin cell level in this configuration: 99.9% coulombic efficiency over 400 cycles, low nucleation overpotential of 40mV and 10mV hysteresis at 0.2mA cm-2, without dendrite formation. To demonstrate the scalability of the anode-free concept, we attempted plating and stripping of sodium metal on copper foils with areas that are 10-fold higher (>10 cm2) than those previously achievable in coin cells (~1cm2) using a split pouch cell configuration. Furthermore, we investigate the effect of pressure at this scale by using two methods. The initial method involves increasing spacer thickness, which acts to compress a wave spring within the split pouch cell. These experiments demonstrate that the plating and stripping voltage hysteresis can be decreased from 125mV -> 40mV -> 10mV, with increasing spacer thickness on the order 3mm -> 3.5mm -> 4mm. The hysteresis observed in coin cells is then matched when 4mm of spacers is used in split pouch cells, indicating a similar pressure applied in these two cell formats. Voltage instabilities are also reduced by increasing the spacer thickness, indicating the formation an increasingly stable solid electrolyte interface (SEI). Secondly, the optimal pressure for the Na||Cu half-cell is investigated by using a pressure calibration unit to accurately measure the applied force within a compressive jig.
References:
[1] Chengtian Zhou et al 2021 J. Electrochem. Soc. 168 060532

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(Digital Presentation) Electrochemical Measurements of Solvent Co-Intercalation Phenomenon Enabling Sodium-Ion Electrolyte Optimization for Graphite Anodes
Authors: Åvall Gustav , Son Youhyun , Alvarez Ferrero Guillermo , Janßen Knut , Adelhelm Philipp 
Published: July 2022

Sodium-ion batteries (SIBs) is one of the more promising battery technologies that are starting to see commercialisation, were the low cost, abundance of necessary raw materials, higher safety and power and similar energy densities compared to lithium-ion batteries (LIBs) are often mentioned as their key advantages. SIBs, due to their great similarities with LIBs have seen a rapid development. One of the key differences, however, is the carbonaceous negative electrode, where SIBs, due to Na+ not forming stable intercalation compounds with graphite, the anode of choice for LIBs, are forces to use hard carbons. But, it was recently discovered by Jache et al.
1 that Na+ can form stable ternary graphite intercalation compounds through a solvent co-intercalation mechanism, thus enabling the use of graphite in SIBs. This sparked several follow-up studies exploring solvent co-intercalation as a way to use graphite in SIBs2, but the question of how many solvent molecules are intercalated along with the cation, and thus the stoichiometry of the redox reaction, was never settled. Here, we present a novel electrochemical method to directly measure the number of solvents that are brought along by the cation into the graphite host structure.
The SIBs using the co-intercalation mechanism to enable the use of graphite has so far shown great kinetics, power densities and extreme cyclability, with great capacity retention over thousands of cycles2. They are, however, plagued by a low specific capacity, a great volume expansion, and high average voltage in half-cells vs. Na+/Na, leading to poor energy density. But, the knowledge of how many glymes entering the graphite host gained from our measurements enabled us to rationally design new electrolytes, composed of low amounts of glymes mixed with another co-solvent, that both increases the energy density of the system, by lowering the average voltage while retaining the capacity, and reduces the volume expansion, while also reducing the cost of the electrolyte (Figure 1). The impact of the new electrolytes on the structure of graphite is studies using operando dilatometry and XRD, while the local structure in the electrolyte is investigated with ab initio methods – together giving a comprehensive view of the system.

Figure 1. Voltage profile of new electrolytes, showing a lowering of the average voltage a second plateau, and snap shot from ab initio molecular dynamics.

References:

B. Jache, P. Adelhelm, Angew. Chem. Int. Ed. 2014, 53, 10169-10173, DOI: 10.1002/anie.201403734

J. Park, Z-L. Xu, K. Kang, Front.
Chem., 2020, 8:432, DOI: 10.3389/fchem.2020.00432

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(Invited) N@C60 and N@C70 for Quantum Information Processing: Beyond Qubits
Authors: Porfyrakis Kyriakos 
Published: July 2022

Endohedral fullerenes such as N@C60, where a single atomic nitrogen is trapped inside the fullerene cage, have been proposed as qubit architectures due to the remarkably long relaxation times of their p-electron spins (T1 = 0.375 ms, T2 = 0.25 ms). Molecular quantum computers are still at the fringes of the field as recent developments have focused on other implementations such as superconducting qubits. However, molecular approaches present some advantages such as the ability to use chemical functionalization for scaling up qubit architectures. This, combined with continuous progress on miniaturization of electrodes via e-beam lithography and other techniques, means that molecular approaches will continue to be of interest.
In this talk, I will review the field of fullerene-based quantum information processing. I will present progress on the synthesis, chemical functionalization and alignment of N@C60 and N@C70 in different matrices. Recently, we were able to align N@C60 and N@C70 derivatives in a liquid crystal matrix with ordering parameter Ozz
= 0.61. With the aligned samples, we were able to achieve addressability of the available 4-electron spin levels in endohedral nitrogen by coherent manipulations.
Furthermore, these functionalized molecules give rise to endohedral fullerene qudits: multi-level computational units alternative to the conventional 2-level qubits. Qudits offer a larger state space for encoding information and thus can offer enhancement of quantum algorithm efficiency. Indeed, we were able to demonstrate the first ever geometric phase using pulsed EPR; something that was first proposed over 30 years ago!
Electrochemical Characterization and Application of Graphene Oxide Materials Obtained By Electrochemical Exfoliation of Graphite
Authors: LEI Yuting , Ossonon Benjamin , Perreault Jonathan , Tavares Ana 
Published: July 2022

Graphene oxide (GO) materials possess oxygen functional groups located at the edges and at the surface of the graphitic layers, confering them dispersibility in water, biocompatibility, and high affinity for specific molecules. These properties are highly appealing for their use in electrochemical sensors. However, the density and type of functional groups and defects in these materials also influence the heterogeneous electron transfer rate of redox processes occurring at the GO-based electrodes 1,2. In this respect, it is necessary to investigate the physicochemical and electrochemical properties of GO materials to choose the most suitable one for a target application.
Here, we report a simple and facile platform for the electrochemical characterization of GO materials 3. The GO sheets are self-assembled on a glassy carbon electrode (GCE) through an aminophenyl-film linker (AP) through electrostatic interaction and pi-pi stacking, Figure 1a. Then, the modified electrodes are characterized by cyclic voltammetry with 1 mM [Fe(CN)6]3-/4- redox couple to determine the electrochemical surface area (ESA) through the Randles-Sevcik equation and to calculate the standard rate constant of electron transfer (k0) by the Nicolson method.
In this work, series of GO materials were obtained by electrochemical exfoliation of graphite in 0.1 M H2SO4. The electrochemical exfoliation of graphite in aqueous solution is an easy and “green” method that allows the synthesis of large amounts (in the order of grams) of materials (EGO: electrochemically exfoliated graphene oxide) with tunable composition in a short time (few hours). The applied voltage and the distance between the graphite and the counter electrodes were varied, Figure 1b, to obtain EGOs with different physicochemical properties such as the number of layers, structural defects, type and content of oxygenated groups. Transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy analysis were used to investigate the physicochemical properties of the EGOs. As shown in Figure 1c, the measured ESA and k0 scale with each other and are sensitive to the physicochemical properties of EGOs. This confirms the suitability of the proposed platform to characterize the EGO materials 3.
Finally, selected EGO materials were used to fabricate electrochemical aptasensors for the detection of cocaine. The influence of the EGO physicochemical properties on the performance of the aptasensors will be presented and discussed.
References
(1) Kampouris, D. K.; Banks, C. E. Chemical Communications
2010, 46, 8986-8988.
(2) Ambrosi, A.; Bonanni, A.; Sofer, Z.; Cross, J. S.; Pumera, M. Chemistry – A European Journal
2011, 17, 10763-10770.
(3) Lei, Y.; Ossonon, B. D.; Chen, J.; Perreault, J.; Tavares, A. C. Journal of Electroanalytical Chemistry
2021, 887, 115084.

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Out-of-Plane Polarized Visible Luminescence and Electronic Resonance in Black Phosphorus
Authors: Schue Leonard , Goudreault Felix A. , Righi Ariete , Resende Geovani C. , Lefebvre Valerie , Godbout Emile , Pimenta Marcos A. , Cote Michel , Francoeur Sebastien , Martel Richard 
Published: July 2022

After reports of high mobility and a tunable bandgap covering a wide spectral range from the visible to the mid-infrared region, layered black phosphorus (BP) has emerged as a promising 2D material for high performance electronic and optoelectronic devices. Owing to its orthorhombic crystallographic structure, black phosphorus expresses strong anisotropic properties. While recent investigations on few-layers crystals have extensively explored the in-plane anisotropy, much less attention has been given to the out-of-plane direction.
In this work, we use polarization-resolved photoluminescence (PL) and Raman spectroscopies to investigate the band structure anisotropy of bulk BP along the in-plane (zigzag, armchair) and out-of-plane directions. An unexpected room-temperature luminescence is detected in the visible, and strongly polarized in the out-of-plane direction. This emission, detected at 1.75 eV far above the band gap (0.3 eV), is surprising as it violates Kasha's rule which favors light emission from the lowest energy states. To elucidate its origin, we have systematically examined the characteristics of this luminescence as a function of polarization, temperature and excitation energy. These results reveal an unreported out-of-plane resonance at 2.3 eV in both the PL and Raman responses. Polarization selection rules and density functional theory (DFT) calculations of the complex dielectric permittivity are used to understand the origin of the strongly polarized optical response and demonstrate the remarkable extent to which the anisotropy influences the optical properties and carrier dynamics in black phosphorus.
(Invited) Van Der Waals Growth and in Situ Studies of Two-Dimensional Pnictogens
Authors: Moutanabbir Oussama , Fortin-Deschenes Matthieu 
Published: July 2022

With their ns2 np3 electron configuration and sp3 hybridization, pnictogens (N, P, As, Sb, Bi) form a unique class of elemental van der Waals (vdW) and two-dimensional (2D) materials. The layered allotropes and the wide range of atomic masses span by pnictogens endows them with a broad spectrum of electronic, optical, and topological properties. For instance, few-layer black phosphorus and arsenic have thickness-dependent direct bands spanning the visible and near infrared, as well anisotropic transport properties. On the other hand, 2D-Sb and 2D-Bi are predicted to exhibit several topological phase transitions near atomic thicknesses, as well as a high-mobility single layer semiconducting phase. Despite the important technological potential of 2D pnictogens, stability and synthesis challenges impede their integration in emerging technologies. This talk presents theoretical and real-time electron microscopy studies of the vdW growth and stability of 2D pnictogens [1-6]. The insights obtained from these studies lay the groundwork for the integration of this new class of 2D materials in emerging electronic, optoelectronic, and quantum technologies.
References

Fortin-Deschênes, H. Zschiesche, T. O. Menteş, A. Locatelli, R. Jacobberger, F. Genuzio, M. J. Lagos, D. Biswas, C. Jozwiak, J. A. Miwa, S. Ulstrup, A. Bostwick, E. Rotenberg, M. S. Arnold, G. A. Botton, O. Moutanabbir. Pnictogens Allotropy and Phase Transformation during van der Waals Growth. Nano Letters. 2020; 20 (11), 8258-8266.

Fortin-Deschênes, O. Waller, Q. An, M. J. Lagos, G. Botton, H. Guo, O. Moutanabbir. 2D Antimony-Arsenic Alloys. Small. 2020; 16, 1906540.

Fortin-Deschênes, R. M. Jacobberger, C. A. Deslauriers, O. Waller, É. Bouthillier, M. S. Arnold, O. Moutanabbir. Dynamics of Antimonene–Graphene Van Der Waals Growth. Advanced Materials. 2019; 1900569.

Fortin-Deschênes, O. Moutanabbir. Recovering the Semiconductor Properties of the Epitaxial Group V 2D Materials Antimonene and Arsenene. The Journal of Physical Chemistry C. 2018; 122(16), 9162–9168.

Fortin-Deschênes, O. Waller, T. O. Mentes, A. Locatelli, S. Mukherjee, F. Genuzio, P. Levesque, A. Hebert, R. Martel, O. Moutanabbir. Synthesis of Antimonene on Germanium. Nano Letters. 2017; 17(8), 4970–4975.

Fortin-Deschênes, P. Levesque, R. Martel, O. Moutanabbir. Dynamics and mechanisms of exfoliated black phosphorus sublimation. The Journal of Physical Chemistry Letters. 2016; 7(9), 1667-1674.
(Invited, Digital Presentation) Molecular Self-assembly and Reactivity on 2D Layered Materials
Authors: De Feyter Steven 
Published: July 2022

In the first part, we will focus on the principles of self-assembled molecular network formation at the liquid-solid interface on surfaces such as graphite, MoS2, and graphene. Then we will discuss how lateral confinement, induced by covalent functionalization of graphite and graphene, affects self-assembly. Several strategies will be demonstrated to realize two-dimensional lateral confinement, all based on the covalent modification of the surface, making use of bottom-up approaches or a combination of bottom-up and top-down approaches. The impact of these various types of confinement on the formation of self-assembled molecular networks will be discussed, including aspects such as nucleation and growth, directional self-assembly, on-surface chirality, polymorphism, and reactivity.
In a second part, we will focus on the formation of porous two-dimensional covalent organic frameworks at the liquid-solid interface, and reveal various interesting aspects at the molecular level such as nucleation and growth mechanisms, and the impact local electric fields may have on (de)polymerization processes.
The relevance and importance of scanning probe microscopes to investigate (and control) self-assembly and reactivity on surfaces will be illustrated.

C. Rodríguez González, A. Leonhardt, H. Stadler, S. Eyley, W. Thielemans, S. De Gendt, K. S. Mali, S. De Feyter, ACS Nano, 2021, 15, 10618–10627

Verstraete, S. De Feyter, Chem. Soc. Rev., Chemical Society Reviews, 2021, 50, 5884–5897

Bragança, A. Minoia, R. Steeno, J. Seibel, B. E. Hirsch, L. Verstraete, O. Ivasenko, K. Müllen, K. S. Mali, R. Lazzaroni, S. De Feyter, J. Am. Chem. Soc., 2021, 143, 11080–11087

Tahara, Y. Kubo, S. Hashimoto, T. Ishikawa, H. Kaneko, A. Brown, B. E. Hirsch, S. De Feyter, Y. Tobe, J. Am. Chem. Soc., 2020, 142, 7699–7708

Zhan, Z.-F. Cai, M. Martínez-Abadía, A. Mateo-Alonso, S. De Feyter, J. Am. Chem. Soc. 2020, 142, 5964–5968
Unravelling the Topological Edge States of Twisted Bilayer Graphene
Authors: Fortin-Deschenes Matthieu , Pu Rui , Ma Chao , Zhou Yanfeng , Zhang Fan , Du Xu , Xia Fengnian 
Published: July 2022

Stacking two slightly lattice-mismatched or relatively twisted two-dimensional (2D) materials gives rise to an unexpected richness of physical phenomena due to the emerging moiré pattern. In particular, twisted-bilayer graphene (t-BLG) has recently been shown to host strongly correlated phases as well as unconventional superconductivity [1, 2]. While recent studies have hinted at the non-trivial topology of the moiré bands [3, 4], direct experimental observations of the topological edge states are still conspicuously missing. Herein, using superconducting quantum interference, we reconstruct the real-space current distribution in t-BLG Josephson junctions (JJs) and reveal the presence of conductive edge states when the Fermi level is placed in the superlattice induced band gaps. These results suggest the non-trivial topology of t-BLG and lay the groundwork to understand and exploit the edge states in moiré materials.
[1] Cao, Y.; Fatemi, V.; Fang, S.; Watanabe, K.; Taniguchi, T.; Kaxiras, E.; Jarillo-Herrero, P. Nature 2018, 556, (7699), 43.
[2] Cao, Y., Fatemi, V., Demir, A., Fang, S., Tomarken, S. L., Luo, J. Y., ... & Jarillo-Herrero, P. (2018). Nature, 556(7699), 80-84.
[3] Park, M. J., Kim, Y., Cho, G. Y., & Lee, S. (2019). Physical review letters, 123(21), 216803.
[4] Ma, C.; Wang, Q.; Mills, S.; Chen, X.; Deng, B.; Yuan, S.; Li, C.; Watanabe, K.; Taniguchi, T.; Du, X.; Zhang, F.; Xia, F. Nano Letters 2020, 20, (8), 6076-6083.
(Invited, Digital Presentation) Synthesis and Atomic Scale Characterization of 2D Layered Heterostructures Atom by Atom: An Ultra-high Resolution Aberration-corrected Electron Microscopy Study
Authors: Alem Nasim 
Published: July 2022

Defects can have a profound effect on the macroscale physical, chemical, and electronic properties of nanostructures. They can lead to structural distortions, introduce extra states in the band gap and give rise to excess potential locally at buried interfaces. While defects and interfaces have been a well-studied subject for decades, little is known about their local atomic and chemical structure, sub-Angstrom structural distortions within their vicinity.
Using ultra-high-resolution aberration-corrected S/TEM imaging and spectroscopy, this talk will discuss our recent efforts on the determination of the defect chemistry and sub-Angstrom relaxation effects in nanostructures around at the interfaces in the family of 2D crystal heterostructures. In the family of 2D crystal transition metal dichalcogenides (TMDs) alloys, we report how on anisotropy of the building blocks in the 2D heterostructure, such as ReS2/MoS2 and WS2/Graphene, and their epitaxy and strain at the interface can affect their nucleation and growth. This work will further uncover the structural distortions that occur in these heterostructure across various length scales and reveals the underlying physics of the formation of such heterostructures and their strain state resulting from CVD synthesis.
(Invited, Digital Presentation) Influence of Hemisphere-Shaped Nanodimples of Gold Electrode on Capacitance in Ionic Liquid
Authors: Imanishi Akihito 
Published: July 2022

Ionic liquids (ILs) have attracted much attention as promising electrolytes for electrochemical devices due to their wide electrochemical window (stability) and negligible vaporization. For such applications, nanostructured electrodes have advantage on their large surface area leading to accumulation of large density energy at the interface. However, recent reports on IL/electrode interfaces revealed that quite unique structures can be formed, and it is not clear how the interface forms and how it changes by forming an electric double layer (EDL). In this study, we investigated the interfacial capacitance of nanostructured Au electrodes using electrochemical impedance spectroscopy (EIS) and IR measurements.
Polystyrene beads were self-assembled in a close packed form on a gold substrate by dipping in polystyrene beads solution and rapid drying. Au electrodeposition on thus prepared surface followed by removal of the beads resulted in the fabrication of a nanostructured Au electrode with periodic dimples. Electrochemical behavior of a ferrocene dissolved ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) amide (BMI-TFSA)) at the nanostructured and flat Au electrodes were investigated by EIS. We found that the capacitance of the nanostructured electrode was smaller than that of the flat electrode in the whole potential range. This result suggests that the thickness of the electric double layer formed in the nano-sized dimple is thicker than that formed on the flat surface. In the case of nanostructured Au electrode having 160 nm diameter dimples, the large capacitance was observed comparing with other electrodes having the dimples of different sizes. In addition, on the negative-going scan, the capacitance takes maximum at 0.1 V vs. Fc/Fc+, whereas no peak was found on the reverse positive-going scan. This result indicates that the exchange of cation/anion layers smoothly proceeded on the negative-going scan, whereas such a smooth exchange was prevented due to strongly surface-adsorbed BMIM+ on the positive-going scan. We also found that the hysteresis behavior was relatively suppressed in the case of the electrodes having 70 nm and 120 nm diameter dimples. We carried out the In-situ ATR-IR measurement to investigate the structure of ionic liquid molecules at the ionic liquid/electrode interface. The details of the relationships between the arrangement of ionic liquid at the interface and the capacitance of the electrode will be discussed.
(Invited) Synthesis and Photophysical Properties of Platinum(II) Complexes Having Electron Donor/Acceptor Moieties
Authors: Sakuda Eri 
Published: July 2022

Boron containing π-electron chromophores represented by tri(9-anthryl)borane show quite unique spectroscopic and photophysical properties, owing to the presence of the vacant p-orbital on the boron atom. In practice, we demonstrated that the excited states of arylborane derivatives were characterized by charge transfer from the π-orbital of the aryl group to the vacant p-orbital on the boron atom: π(Ar) – p(B) CT. If such π(Ar) – p(B) CT interactions are introduced to the MLCT excited state of a transition metal complex, new and novel aspects into photophysics of the metal complexes could be demonstrated. We have previously reported our experiments on the platinum(II) complexes having arylborane-appended 2,2’:6’,2”-terpyridine (tpy) ligands to demonstrate synergetic metal(M) – ligand and π(Ar) – p(B) CT interactions.
In the present study, we focus on donor-acceptor interaction using an arylborane substituent and discussed about the charge separation on the spectroscopic and photophysical properties of their metal complexes. Then, we synthesized a novel cyclometalated-type platinum (II) complex using an NCN tridentate ligand with boron substituents, which is thought to cause intermolecular interactions, and investigated its spectroscopic properties.

Figure 1