bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Kinetic Selectivity of Chemical Vapor Deposition Growth of Carbon Nanotubes
Authors: Otsuka Keigo , Inoue Taiki , Xiang Rong , Chiashi Shohei , Kato Yuichiro K. , Maruyama Shigeo
Published: July 2022

Single-walled carbon nanotubes have been a candidate for outperforming silicon in ultrascaled transistors, but the realization of nanotube-based integrated circuits requires dense arrays of purely semiconducting species. In order to directly growth such nanotube arrays on wafers, control over kinetics and thermodynamics in tube-catalyst systems plays a key role, and further progress requires the comprehensive understanding of seemingly contradictory reports on the growth kinetics. Here, we propose a universal kinetic model that decomposes the growth rates of nanotubes into the adsorption and removal of carbon atoms on the catalysts, and provide its quantitative verification by ethanol-based isotope labeling experiments. While the removal of carbon from catalysts dominates the growth kinetics under a low supply of precursors, our kinetic model and experiments demonstrate that chiral angle-dependent growth rates emerge when sufficient amounts of carbon and etching agents are co-supplied. The kinetic maps, as a product of generalizing the model, include several kinetic selectivities that emerge depending on the balance of gases with opposing effects. Our findings not only resolve discrepancies existing in literature, but also offer rational strategies to control chirality, length, and density of nanotube arrays for practical applications.

Part of this work was supported by JSPS (KAKENHI JP20K15137, JP20H00220) and JST (CREST JPMJCR20B5).
(Invited) Thermoexcitonic Properties of Carbon Nanotubes
Authors: Miyauchi Yuhei
Published: July 2022

Single-walled carbon nanotubes (SWCNTs) are representative low dimensional nanomaterials showing various intriguing excitonic properties [1-7]. Owing to the large binding energy of quasi one-dimensional excitons on the order of 0.3-0.5 eV, many of the excitonic phenomena can be observed even at elevated temperatures, which is opening up unprecedented applications of excitons in energy science and thermal engineering. I will discuss our recent progress in the studies on the excitonic thermal light emission properties of SWCNTs and their application in heat-to-light energy conversion devices. [1] Y. Miyauchi et al., Nat. Photonics 7, 715 (2013). [2] N. Akizuki, Y. Miyauchi et al., Nat. Commun. 6, 8920 (2015). [3] Y. Miyauchi et al., Phys. Rev. B, 92, 205407(2015). [4] A. Takakura, Y. Miyauchi et al., Nat. Commun. 10, 3040 (2019). [5] T. Nishihara, Y. Miyauchi et al., Nat. Commun. 9, 3144 (2018). [6] S. Konabe, T. Nishihara, Y. Miyauchi, Opt. Lett. 46, 3021 (2021). [7] T. Nishihara, Y. Miyauchi et al., submitted.
(Digital Presentation) Excitonic Photoluminescence Properties of Locally Functionalized Single-Walled Carbon Nanotubes Using Molecular Modifiers
Authors: Shiraki Tomohiro , Hayashi Keita , Niidome Yoshiaki , Aoki Haruka , Fujigaya Tsuyohiko
Published: July 2022

Excitons in single-walled carbon nanotubes (SWCNTs) show unique properties due to strong quantum confinement and weak dielectric screening effects which give rise to high binding energies based on strong Coulombic interactions. By this feature, stable and mobile excitons are generated in SWCNTs and its radiative recombination produces photoluminescence (PL) in the near infrared (NIR) region. Recently, local chemical functionalization of SWCNTs has attracted great attention because of enhancement of their NIR PL properties.[1-5] This functionalization dopes local defects such as sp3 carbon to the semiconducting sp2 carbon networks of SWCNTs based on the covalent bond formation between the tube walls and modifier molecules. As a result, emissive doped sites that have narrower band gaps and exciton trapping features are created in the locally functionalized SWCNTs (lf-SWCNTs). For lf-SWCNTs, E
11* PL newly appears with red-shifted wavelengths and increased PL quantum yields compared with original E
11 PL of pristine SWCNTs. Currently, chemical functionalization methods and E
11* PL wavelength modulation techniques are being developed for further functionalization of lf-SWCNTs. [1-5] In this presentation, E
11* PL properties of lf-SWCNTs synthesized using newly designed chemical modifiers are discussed. For example, an azide compound is found to produce the emissive doped sites in lf-SWCNTs via a [2+1] cycloaddition reaction. The E
11* PL peak was observed at 1118 nm and N1s peak in X-ray photoelectron spectroscopy was detected around 400 eV regions based on the chemical bond formation. Moreover, solvatochromic PL energy shifts of the E
11* PL showed a different trend from those observed for typical lf-SWCNTs synthesized using diazonium chemistry. This result indicates that the chemical structures of the doped sites could be a key factor to modulate excitonic properties of localized excitons in lf-SWCNTs. Therefore, the molecular chemistry approach would provide unique exciton engineering tools for lf-SWCNTs and develop advanced excitonic NIR materials applicable to quantum cryptography technologies and high-performance bio/medical imaging and sensing.

[1] T. Shiraki, Chem. Lett., 50, 397 (2021); [2] T. Shiraki et al., Acc. Chem. Res., 53, 1846 (2020); [3] S. Tretiak et al., Acc. Chem. Res., 53, 1791 (2020); [4] Y. Wang et al., Nat. Rev. Chem., 3, 375 (2019); [5] J. Zaumseil, Adv. Optical Mater. 2101576 (2021).
(Invited, Digital Presentation) Carbon Nanotube-Based Nanomechanical Signal Receiver
Authors: Funayama Kieta , Tanaka Hiroya , Hirotani Jum , Shimaoka Keiichi , Ohno Yutaka , Tadokoro Yukihiro
Published: July 2022

Carbon nanotube(CNT) has attracted much attention as one of the nanomaterials for future sensing devices because of their excellent properties. The mechanical vibration of an individual CNT has shown outstanding potential for detecting the force1, mass2, electromagnetic waves3 sensitively via CNT’s elastic and electric properties, chemical stability, and lightweight structure. In terms of communication field, some research groups have suggested the concept of the mechanical signal receiver consisted of CNT3,4,. Although the previous studies have achieved to show the basic demonstration via the detection of electromagnetic signal, there have not been a research that quantitatively evaluates the communication performance and considers the effect of noise has been absent. In addition, it is significant to investigate the comprehensive systems include such CNT-based mechanical sensor.

Herein, we experimentally demonstrate for the first time that a CNT-based signal receiver can transfer a large amount of digital data, 393,216 bits, encoded from a color image5. Although there are some errors in bit decision from the received signal, we successfully decode the original digital image data by combining error collection. In addition, we experimentally evaluate the communication performance of the CNT-based mechanical receiver. The channel capacity obtained by the demonstration indicates that the data-transfer capability approaches the theoretical limitation. The results show that the nanoscale mechanical receiver has great potential for contributing to the incoming new technology relates our life, e.g., internet of things (IoT) and artificial intelligence (AI) by combining with information and communication technology.

1) Jensen, K. Kim, A. Zettl, Nature Nanotecnol.,
3, 533, (2008).

2) Moser, J. Guttinger, A. Eichker, M. J. Esplandiu, D. E. Liu, M. I. Dykman, A. Bachtold, Nature Nanotecnol., 8, 493 (2013).

3) Jensen, J. Weldon, H. Garcia, A. Zwttl, Nano Lett., 7, 3508 (2007).

4) Gouttenoire, T. Barois, S. Perisanu, J.-L. Leclercq, S. T. Purcell, P. Vincent, A. Ayari, Small, 6, 1060 (2010).

5)Funayama, H. Tanaka, J. Hirotani, K. Shimaoka, Y. Ohno, Y. Tadokoro, ACS Appl. Nano Mater., 10.1021/acsanm.1c02563 (2021).
Polyazaacenes Generation By Using Precursor Methods
Authors: Chan Yee Seng , Hayashi Hironobu , Aratani Naoki , Yamada Hiroko
Published: July 2022

Azaacenes are the analogue of acenes, comprising nitrogen atoms in the carbon-based molecular skeleton, have been gaining attention because of their potential application in organic electronics and material science. However, it is normally difficult to synthesize such large aromatic molecules because of the poor solubility and low stability. On the other hand, we have developed precursor methods to overcome these problems. Briefly, bicyclo[2.2.2]octadiene(BCOD)-fused acenes can be converted its corresponding acenes by thermally induced retro-Diels–Alder reaction, while α-diketone-type precursors can be converted simply by photoirradiation.[1] Significantly, these precursor molecules are often more soluble and stable than its converted forms. More crucially, their corresponding acenes can be prepared quantitatively in solutions or in films, if the precursors are sufficiently pure. So far, by using the precursor methods, we have successfully synthesized polyacenes under anaerobic conditions either at ultrahigh vacuum conditions or at the interior of single crystals to avoid undesirable oxidation of the resulting polyacenes.[2–4]

Here we report a series of tetraazapolyacene precursors synthesis. Briefly, the BCOD moieties were introduced in the tetraazaacenes as the thermally removable leaving group. The possibility of conversion of the precursors into its corresponding tetraazaacenes was examined by thermogravimetric analysis respectively. In addition, α-diketone-type precursor of tetraazaheptacene was also synthesized. Furthermore, we also report the one-pot synthesis of macrocyclic azacyclacene precursor by reacting bis-α-diketo-tetrahydro-diethanopentacene with benzene-1,2,4,5-tetraamine tetrahydrochloride. Here, the targeted compound was clearly confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The obtaining precursor compounds will be subjected to transformation to investigate its optical and physical properties.

References

H. Yamada, D. Kuzuhara, M. Suzuki, H. Hayashi, N. Aratani, Bull. Chem. Soc. Jpn.
2020, 93, 1234–1267.

J. I. Urgel, S. Mishra, H. Hayashi, J. Wilhelm, C. A. Pignedoli, M. D. Giovannantonio, R. Widmer, M. Yamashita, N. Hieda, P. Ruffieux, H. Yamada, F. Roman, Nat. Commun.
2019, 10, 861.

H. Hayashi, N. Hieda, M. Yamauchi, Y. S. Chan, N. Aratani, S. Masuo, H. Yamada, Chem. Eur. J.
2020, 26, 15079–15083.

K. Eimre, J. I. Urgel, H. Hayashi, M. D. Giovannantonio, P. Ruffieux, S. Sato, S. Otomo, Y. S. Chan, N. Aratani, D. Passerone, O. Gröning, H. Yamada, R. Fasel, C. A. Pignedoli, Nat. Commun. in press.
(Invited, Digital Presentation) Polyaromatic Micelles: Discrete Nanoparticles with Versatile Host Functions in Water
Authors: Catti Lorenzo , Yoshizawa Michito
Published: July 2022

Polyaromatic micelles, assembled from bent anthracene dimers with hydrophilic units, have been established by our group as versatile host structures in water at the nanoscale (Fig. 1a; M. Yoshizawa et al., Acc. Chem. Res.
2019, 52, 2392). We here report recent efforts into the direction of bioapplications of these micelles via deliberate modifications of the amphiphile design. Utilization of an ortho-dianthrylbenzene core is shown to allow construction of photoresponsive micelles capable of quantitative guest release via light irradiation, which is potentially useful for drug delivery (Fig. 1b). In addition, attachment of hydrophilic mannose units to the anthracene dimer framework is demonstrated to yield highly fluorescent saccharide clusters capable of selective interactions with proteins (Fig. 1c).

Figure 1
(Invited) Room-Temperature Molecule Trapping at Plasmonic Metal Nanostructures
Authors: Murakoshi Kei
Published: July 2022

To control of the motion of individual molecules at room temperature, optical tweezers could be the choice of the methods to realize the desirable selectivity with high resolution in time and space. In this study, we demonstrated plasmonic optical trapping of small molecules at the gap of a single metal nanodimer immersed in an electrolyte solution. In situ electrochemical surface-enhanced Raman scattering measurements proved that the plasmonic structure realized selective molecular condensation leading to the formation of unique mixed molecular phases that were distinct from those under thermodynamic equilibrium in nano scale.
Medium-Temperature Sodium-Iodine Battery System
Authors: Schäfer Frank , Holzapfel Michael , Tübke Jens
Published: July 2022

A medium-temperature sodium-iodine battery system is presented. The rechargeable molten-sodium system works at approx. 100 °C with high efficiency, and potentially lower cost than existing high-temperature sodium-batteries (which are usually operating at a temperature of around 300 °C). Our battery system uses an aqueous iodine/iodide solution as catholyte and sodium-ion conductive Zr-based NaSICON ceramic material as solid electrolyte. The free halogen, which is formed upon charge, is complexed as highly soluble triiodide. Long-term stability of sodium-ion conductive material in contact with aqueous electrolytes, generally, is a concern. NaSICON-based ceramic material has shown not only an enhanced stability [1] against these electrolytes but also an increased sodium-ion conductivity [2], compared to sodium β″-alumina used in sodium-sulfur batteries. The sodium-iodine system has shown to operate in a stable manner with a catholyte allowing for a high total iodine concentration (>3.0 mol/L) [1]. Substitution in the NaSICON composition allows for increased ionic conductivity and enhanced stability against the aqueous cathode. In the case of fissuring of the NaSICON ceramic separator, only solid products are formed. This stops the direct reaction of active materials.

[1] M. Holzapfel, D. Wilde, C. Hupbauer, K. Ahlbrecht, T. Berger, Electrochim. Acta 237 (2017), 12-21.

[2] S. Naqash, Q. Ma, F. Tietz, O. Guillon, Solid State Ionics 302 (2017), 83-91.

This work is funded by the German Federal Ministry of Education and Research in the project „MiTemp – Mitteltemperatur-Natriumbatterien mit flüssiger Natriumanode und wässriger Iodkathode“ (03XP0183A).

Figure 1
In-Operando FTIR Study on the Redox Behavior of Sulfurized Polyacrylonitrile As Cathode Material for Li-S Batteries
Authors: Pereira Rhyz , Sarode Krishna Kumar , Rafie Ayda , Kalra Vibha
Published: July 2022

Sulfurized polyacrylonitrile (SPAN) has been shown to be an attractive cathode material for Lithium-Sulfur (Li-S) batteries demonstrating high gravimetric capacity of up to 650mAh/g, and stable cycle performance due to the lack of a polysulfide shuttle in commercially viable carbonate electrolyte. While carbonate electrolyte works well with the cathode of Li-SPAN batteries, it is known to destabilize lithium metal, leading to inactive lithium on the anode and poor coulombic efficiencies (CE). Ether electrolytes in contrast have shown much more stable lithium metal behavior, with consistently high CE. While ether-based electrolytes offer advantages in their ability to stabilize the lithium metal anode, SPAN’s performance in ether-based electrolytes suffers from rapid capacity fade possibly due the dissolution of polysulfide species into the electrolyte during the charge discharge cycle. In this work, we investigated the redox behavior of SPAN in ether electrolytes using in-operando FTIR, and the role of lithium nitrate in cycling stability in SPAN batteries.

Our cyclic voltammetry measurements have revealed that the presence of lithium nitrate in sufficient concentration (0.5M) prevents the appearance of redox peaks at 2.1V and 2.3V associated with soluble polysulfides seen in cells using ether electrolyte lacking lithium nitrate. High concentrations of lithium nitrate also prevented rapid capacity loss in cells made using ether electrolyte during long term cycling. XPS measurements showed higher concentrations of lithium fluoride in cells cycled with high concentrations of lithium nitrate, suggesting the formation of a robust cathode electrolyte interface. We developed an in-situ FTIR cell utilizing an attenuated total reflectance (ATR) accessory that can detect the major features of SPAN, such as the cyclized ring structure, the C-S bond, and the S-S bonds. For the in-operando cell, we fabricated a freestanding SPAN cathode and constructed a Li-SPAN cell on top of the ATR accessory. We examined the behavior of polysulfides to understand the role that lithium nitrate plays in preventing the shuttle effect by examining the S-S vibrational modes at 500 cm-1. Additionally, we studied the interactions between the lithium ion and the carbon backbone of SPAN by examining the cyclic behavior of vibrational modes associated with SPAN’s ring structure in the fingerprint region (1000-1500 cm-1), and ring breathing modes (800 cm-1). These peaks disappear during discharge from our in-situ spectra when the cell is at 1.7 V, which corresponds with the major redox peak of SPAN and reappears and returns to its initial position at 2.35V during charge. This indicates that the change in the ring structure is associated with a redox process, which we attribute to the intercalation of lithium into the SPAN structure.
Zero-Emission Solutions for MW-Scale Energy Systems
Authors: Fortin Patrick
Published: July 2022

The overall aim of this project is to establish a generic modelling platform for the design and operation of zero-emission MW-scale hybrid electric energy systems, with a particular focus on maritime transport applications. The project seeks to integrate battery and fuel cell degradation models with operating strategy models to minimize the total cost of ownership (TCO) of hybrid battery/fuel cell systems. The modelling approach used here, to simulate battery and fuel cell degradation, takes advantage of empirical modelling methods already established in the scientific literature. This approach offers three distinct advantages over alternative multi-physics models, in that empirical degradation models are (i) computationally efficient, (ii) can be integrated into other modelling frameworks, and (iii) can support the quick parameterization of different systems.

Real-life battery and fuel cell degradation data, collected using state-of-the-art materials, was used to quantify the model parameters and validate the proposed degradation models. A variety of advanced in-situ electrochemical characterization methods have been employed to quantify the relevant parameters at the beginning-of-life and again after various stages of ageing to determine degradation rates of the relevant parameters.

The second aspect of this project is the implementation of a technoeconomic optimization model that combines the data-driven degradation models with additional inputs such as operating conditions, operational profile (i.e., drive cycle), cost of hydrogen, cost of electricity, etc. to design optimal hybrid battery/fuel cell systems and determine optimal control strategies to minimize degradation and total cost of ownership over the system lifetime.

This talk will focus on the advanced in-situ electrochemical techniques that have been used to extract fuel cell degradation parameters and provide an overview of both the empirical degradation and technoeconomical models. Finally, we will present the optimization results obtained using our platform for the implementation of a hybrid energy system in a coastal Norwegian ferry.
(Digital Presentation) Kinetic Studies of Aorfb Posolyte on Graphite Micro-Fiber Electrodes
Authors: El Hage Ranine , Feynerol Vincent , Brites Helu Mariela , Liu Liang , Sehn-Canevesi Rafael-Luan , Fierro Vanessa , Etienne Mathieu
Published: July 2022

Aqueous organic electrolytes used as posolyte for redox flow battery applications are growing in interest due to their fast kinetics on carbon materials. The determination of their kinetic constants remains a necessity for a better understanding of their overall electrochemical behavior but also for a fine evaluation of the effect of surface activation and possible electrode aging during cycling.

However, the studies performed on carbon felts have shown a lack of accuracy due to the macro-porosity and high surface area of these materials, even at very low electrolyte concentrations (10-4 M). Thus, in this study, we propose another system, allowing to shift from the macro to the micro scale: microelectrodes prepared with single fibers extracted from the corresponding graphite porous felt [1-2]. These microelectrodes allow the qualitative study of solutions at higher concentrations (up to 0.5 M in K4[Fe(CN)6]) and a quantitative analysis through EIS and CV modelling for solutions at 10-2 M with the determination of kinetic constants on activated and non-activated single fibers.

In addition, the effect of activation treatments of graphite felts, on the oxidation kinetics of ferrocyanide is investigated through cyclic voltammetry. In fact, this method allows to determine optimal treatment conditions of carbon felts for a better performance of the battery. Moreover, the degradation of the activation over time can be also studied, which means that the same method could be applied for the study of the aging of the felt after cycling in the battery.

References:

[1] L. Landon-Lane, A. T. Marshall, D. A. Harrington, EIS at carbon fiber cylindrical microelectrodes, Electrochemistry Communications, 109 (2019) 106566

[2] L. Landon-Lane, A. J. Downard, A. T. Marshall, Single fibre electrode measurements – A versatile strategy for assessing the non-uniform kinetics at carbon felt electrodes, Electrochimica Acta, 354 (2020) 136709

Acknowledgement:

This work has been supported by the European Union under HIGREEW, Affordable High-performance Green Redox Flow batteries (Grant Agreement no. 875613).
(Digital Presentation) Sol – Gel Process of Activated Carbon Based Silica Nanostructure Using Rice Husk Template for Supercapacitor Applications
Authors: Vijayan R , Suresh Kumar G , Surumbarkuzhali N , K Varadharaj Eswaramoorthy
Published: July 2022

Rice hulls have portrayed large potential in becoming a sustainable biomass source in producing silica, cellulose, and carbon materials, which garnered well-known interest in the middle of researchers. In recent years, silica-based supercapacitors have emerged as leading energy storage devices that can be mostly used in hybrid electric vehicles, memory devices, etc owing to their unique features like fast charge and discharge rate, long cycle life, high power density, high reliability, etc. The objective of the current study is to determine and compare the specific capacitance of pure silica ( SiO2@SP ) and activated carbon added amorphous silica (SiO2 @SA) nanostructures in rice hulls due to the synergistic effects of the sol-gel process. In this study, we have synthesized pure silica SiO2 and activated carbon added amorphous silica (SiO2 @SA) nanostructures using rice hulls template as a silica source via the simple sol-gel method for supercapacitor applications. XRD, FT-IR, and EDX studies characterize that pure silica(SiO2@SP) is present in amorphous form along with activated carbon having a carbon ballades structure in the prepared SiO2@ SA sample. Further, FE-SEM, TEM observation indicates that the prepared sample is consisting of amorphous silica nanospheres added agglomerated carbon nanoparticles having the size of 20 –30 nm. Cyclic voltammetry and galvanostatic charge/discharge studies characterize the supercapacitive behavior of working electrodes fabricated from prepared SiO2@SP and SiO2@ SA nanostructure. The specific capacitances of SiO2@SP nanostructure are about 36,30,28,26,24,23,22,20 and 12 F/g with the current density value of 4, 6, 8,10,12,14,16,18 and 20 A/g, and the specific capacitances of SiO2@ SA nanostructure are about 85,58,48,46,38,34,32, and 26 F/g with the current density value of 4, 6, 8,10,12,14,16,18 and 20 A/g, respectively. The presence of SiO2@SP species in SiO2@SA nanostructure can provide reactive surfaces for the adsorption/desorption charges and it facilitates the charge storage at the surface of the sample. The above results suggested that the prepared SiO2@SA nanostructure has high potential application for comparison than SiO2@SP nanostructure, making electrochemical supercapacitors.
(Digital Presentation) Homogeneously Miscible Fullerene Inducing Vertical Gradient in Perovskite Thin-Film Towards Highly Efficient Solar Cells
Authors: Jeon Il , Woo Han-Young , Kim Kyusun , Wu Ziang
Published: July 2022

Fullerene-based n-type charge-collecting materials have emerged as a solution to high-performance perovskite solar cells. However, their application to perovskite solar cells was limited in the device architecture and only a small amount of fullerene additives could be introduced to the device system, because of the immiscibility of the fullerene species with polar solvents. To overcome this, triethylene glycol monomethyl ether chain-attached fullerene derivatives are synthesized and applied to normal-type perovskite solar cells. The newly synthesized fullerenes exhibit excellent solubility in polar solvents. A novel approach to introducing miscible fullerenes into perovskite devices and inducing a favorable vertical gradient is proposed. Forming an overcoat on an electron-transporting layer and waiting for a few minutes, the fullerene derivatives progressively permeate into the fullerene-doped perovskite active film. By fabricating perovskite solar cells combining direct mixing, overcoating and waiting techniques, a remarkably high device efficiency of 23.34% is achieved. The high performance is attributed to the fullerene additives with a vertical gradient passivating the perovskite defect sites effectively and the overcoat enhancing the charge transfer. The device performance is certified by a national laboratory, which is the highest efficiency among the fullerene additives-used perovskite solar cells.
(Invited) Metal-Cage Interactions in Actinide Mono-Metallofullerenes: Some Insights from Computations
Authors: Rodriguez-Fortea Antonio , Roselló Yannick , Abella Laura , Poblet Josep M.
Published: July 2022

Intensive research has been devoted to the family of closed-cage carbon nanostructures since the discovery of buckminsterfullerene in 1985.1 Endohedral metallofullerene La@C60, with La inside the cage void space, was already detected the same year and La@C82 was isolated few years later.2 During the last two decades, many different M atoms have been encapsulated inside carbon cages of different sizes, in particular those metals of the lanthanide series.3 More recently, the first metallofullerene containing an actinide, Th@C82, was isolated and characterized.4 Later, other mono-actinidofullerenes as non-IPR U@C80, Th@C80 and U@C76; or IPR U@C82, U@C84 and U@C86 have been also characterized.5 In these actinide endofullerenes, the actinide tends to act with oxidation state +4, which involves an important metal-cage interaction with significant covalent contributions. Consequently, the predictions made by the ionic model are less reliable than for lanthanofullerenes. We here analyze in detail this actinide-cage interaction focusing on symmetry aspects of the cage patterns that mostly stabilize the internal actinide.

References

Kroto, H. W.; Heath, J. R.; O’Brien, S. C.; Curl, R. F.; Smalley, R. E. Nature
1985, 318, 162-163.

a) Heath, J. R.; O’Brien, S. C.; Zhang, Q.; Liu, Y.; Curl, R. F.; Kroto, H. W.;Tittel, F. K.; Smalley, R. E. J. Am. Chem. Soc.
1985, 107, 7779-7780; (b) Chai, Y.; Cuo, T.; Jin, C.; Haufler, R. E.; Felipe Chibante, L. P.; Fure, J.; Wang, L.; Alford, J. M.; Smalley, R. E. J. Phys. Chem.
1991, 95, 7564-7568.

Popov, A. A.; Yang, S.; Dunsch, L. Chem. Rev.
2013,
113, 5989-6113.

Wang, Y.; Morales-Martínez, R.; Zhang, X.; Yang, W.; Wang, Y.; Rodriguez-Fortea, A.; Poblet, J. M.; Feng, L.; Wang, S.; Chen, N. J
. Am.
C
hem. Soc.
2017, 139, 5110-5116.

a) Cai, W.; Abella, L.; Zhuang, J.; Zhang, X.; Feng, L.; Wang, Y.; Morales-Martínez, R.; Esper, R.; Boero, M.; Metta-Magaña, A.; Rodriguez-Fortea, A.; Poblet, J. M.; Echegoyen, L.; Chen, N. J. Am. Chem. Soc.
2018, 140, 18039-18050; b) Yao, Y.-R.; Roselló, Y.; Ma, L.; Puente Santiago, A. R.; Metta-Magaña, A.; Chen, N.; Rodriguez-Fortea, A.; Poblet, J. M.; Echegoyen, L. J. Am. Chem. Soc.
2021, 143, 15309-15318.
(Invited) A Carbon Nanotube Binding Bis(pyrenylstyryl)Bodipy-C60 Nano Tweezer: Formation and Photoinduced Charge Separation in Supramolecular C60-Bodipy-SWCNT Triads
Authors: Kazemi Shahrzad , Jang Youngwoo , Liyanage Anuradha , Karr Paul , D'Souza Francis
Published: July 2022

Electron donor-acceptor hybrids comprised of single-wall carbon nanotubes (SWCNT) are promising functional structures having direct applications in energy conversion schemes and molecular optoelectronics. For building such hybrids and exfoliation of SWCNTs, the p-stacking ability of large aromatic compounds such as pyrene is one of the commonly employed approaches. Often, the desired donor or acceptor entities are functionalized to carry one or more pyrene entities and allowed to interact with CNTs. As a suitable electron donor, BODIPYs stand out owing to their ease of structural modifications and rich spectral and redox properties. Consequently, several donor-acceptor conjugates comprised of BF2-chelated dipyrromethene, BODIPY, and the well-known electron acceptor, C60 have been developed. In the present study, we have newly synthesized a nano tweezer comprised of covalently linked BODIPY-C60 carrying two pyrenylstyryl arms, 1. Compound 1 is further allowed to interact with SWCNT(6,5) and SWCNT(7,6) to form the supramolecular C60-BODIPY-SWCNT triads. Upon spectral, electrochemical, and computational characterization, pump-probe spectroscopic studies covering a wide femto-to-millisecond time scale have been performed to establish the occurrence of photoinduced charge separation. The presence of CNT prolonged the lifetime of the charge-separated states revealing the success of the present molecular design strategy for energy harvesting applications.

D’Souza, F.; Sandanayaka, A. S. D.; Ito, O. ‘SWNT-Based Supramolecular Nanoarchitectures with Photosensitizing Donor and Acceptor Molecules’ Phys. Chem. Letts. 2010, 1. 2586-2593.

B. KC, G. N. Lim, and F. D’Souza, ‘Accelerated Charge Separation in Graphene Decorated Multi-Modular Tripyrene-Subphthalocyanine-Fullerene Donor-Acceptor Hybrids,’ Angew. Chem. Int. Ed.
2015, 54, 5088-5092.

Barrejon, L. M. Arellano, F. D’Souza, F. Langa, ‘Bidirectional charge transfer in carbon-based hybrid nanomaterials’ Nanoscale, 2019, 11, 14978-14992.

Figure 1
(Invited) Nanoscale Carbon Allotrope at Zero-Dimension – Small Carbon Nanoparticles Versus Molecular Fullerenes
Authors: Sun Ya-Ping
Published: July 2022

In the vast research field on carbon nanostructures, a seemingly broadly accepted family configuration of nanoscale carbon allotropes is such that fullerenes take the zero-dimensional dot spot, in perfect harmony with one-dimensional carbon nanotubes and two-dimensional graphene nanosheets. More recently, however, a threat to the nice “family value” has been the emergence of small carbon nanoparticles, which are carbon particles of a few nanometers in size without any defined crystal structures or largely amorphous and populated with abundant surface and other defects. The growing experimental evidence has revealed the unique and/or advantageous optical and photoexcited state properties and photoinduced redox characteristics of the small carbon nanoparticles, elevating them to the position of being able to compete with fullerenes for the title of nanoscale carbon allotrope at the zero-dimension. Moreover, a related supporting argument is that fullerenes are molecules, nanoscale in their sizes but not necessarily “nanomaterials” strictly speaking. In this presentation, relevant experimental results of the nanoparticles and fullerenes will be compared for a fair assessment and judgment of their title competition, and more importantly their shared structural features and electronic properties and also their enormous potential in the development of materials for a variety of technological applications will be highlighted.
(Invited) Untethering the Tether Towards Spontaneously Self-Assembled Donuts
Authors: Caballero Ruben , Barrejon Myriam , Cerda Jesus , Arago Juan , Seetharaman Sairaman , de la Cruz Pilar , Orti Enrique , D'Souza Francis , Langa Fernando
Published: July 2022

Functional materials comprised of spontaneously self-assembled electron donor and acceptor entities capable of generating long-lived charge-separated states upon photo-illumination are in great demand as they are key in building the next generation of light energy harvesting devices. However, creating such well-defined architectures is challenging due to the intricate molecular design, multi-step synthesis, and issues associated in demonstrating long-lived electron transfer.

Here, we have newly synthesized, by tether-directed functionalization, a [60]fullerene e-bisadduct carrying two Zn-porphyrins (Figure), and demonstrate supramolecular organization and photophysical events. Remarkably, the supramolecular assembly of the present bisporphyrin-C60 forms donut-shape aggregates, primarily via π-π type charge transfer interactions. Upon photoexcitation, the supramolecular assembly generates long-lived charge-separated states of »1−40 μs lifetime due to electron/hole delocalization within the supramolecular structure

Reference

Caballero, M. Barrejón, J. Cerdá, J. Aragó, S. Seetharaman, P. de la Cruz, E. Ortí, F. D’Souza, F. Langa. J. Am. Chem. Soc. 2021, 143, 11199.

Figure 1
Chemical Isolation of Isomerically Purified Sc3n@C68
Authors: Ashcroft Chloe A. , Stevenson Steven
Published: July 2022

Metallofullerenes with fused pentalenes are rare in arc soot. By far, the majority of endohedral fullerene cages obey the isolated pentagon rule (IPR). In a recent landmark paper (Santiago et al., JACS, 2021, 143, 6037-6042) by the Echegoyen group, they experimentally demonstrated the use of Sc3N@C68 as a new molecular catalyst for Hydrogen Evolution Reactions. Indeed, this fused pentalene metallofullerene (Sc3N@C68) successfully outperformed six other “conventional” (i.e., IPR) endohedrals. Thus, application development for fused pentalene metallofullerenes may open new doors.

In this presentation, we discuss our chemical-based purification approach specifically designed for fused pentalene systems such as Sc3N@C68. We find that after two types of selective chemical reaction, we obtain a highly enriched sample of primarily two species, Sc3N@D3(6140)-C68 and Sc3N@Ih(7)-C80. Due to the large retention time difference between C68 and C80 endohedral cages, only a single injection is necessary for a final purification step.
Stabilizing Metallic Zn Electrode Using Organic Acid Additives in Aqueous Zinc-Ion Batteries
Authors: Na Moony , Byon Hye Ryung
Published: July 2022

Aqueous zinc (Zn)-ion batteries (AZIBs) have been paid attention to as safe, economical, and high-energy-density storages through multiple electron transfer. Although conventional alkaline solution-based AZIBs are primary batteries, recent studies demonstrated the reversible Zn2+ deposition and stripping processes enabled in mildly acidic solutions. It promises the development of rechargeable AZIBs and viable applications for energy storage systems (ESSs). However, metallic Zn employed as the negative electrode has suffered from severe corrosion and precipitation of electrolyte salts in this low pH condition. The Zn electrode undergoes a hydrogen evolution reaction (HER) as Zn2+ is dissolved from the Zn surface. The corrosion leads to a pH rise, precipitating electrolyte salt as zinc hydroxide forms. For example, hexagonal plates of zinc hydroxide sulfate hydrate (Zn4SO4(OH)6∙xH2O, indicated as ZHS) grew on the Zn electrode in 1 M ZnSO4 solution when pH approached ~5.4. The insulating and randomly oriented ZHS increased the surface resistance and caused the non-uniform Zn deposition.

These challenges are mitigated by adding organic acid to the 1 M ZnSO4 solution. As the HER raised pH, the acid was promptly deprotonated, then coordinated with Zn2+. This process caused the thin film formation consisting of three-dimensional zinc glutarate. The zinc glutarate protected the Zn electrode and impeded the electrode corrosion and the ZHS precipitation. We demonstrated a uniform Zn plating and stripping process with 10 mM of organic acid in contrast with dendritic and dead Zn growth in the absence of the additive. Galvanostatic tests of symmetric Zn cells revealed over 1000 h cycles with the additives at a current density of 1 mA cm-2 and a limited capacity of 1 mAh cm-2. In contrast, the Zn cells with the additive-free electrolyte solution exhibited 15 times lower cyclability as micron-scale ZHS plates covered the electrode surface. Our strategy using the cheap additives is feasible to use grid-scale ESSs and shows significantly improved cycling performances. I will present details of Zn surface reactions using organic acid additive and corresponding electrochemical performances in this presentation.
(Invited) Graphene and Related Materials, from Production to Applications
Authors: Ferrari Andrea
Published: July 2022

Disruptive technologies are usually characterised by universal, versatile applications, which change many aspects of our life simultaneously, penetrating every corner of our existence. In order to become disruptive, a new technology needs to offer not incremental, but dramatic, orders of magnitude improvements. Moreover, the more universal the technology, the better chances it has for broad base success. Significant progress has been made in taking graphene and related materials from a state of raw potential to a point where they can revolutionize multiple industries. When it comes to electrochemical applications, Raman spectroscopy is an ideal non-destructive technique to study degradation in graphite anodes, as it is sensitive to doping, strain, defects, and interlayer coupling. I will discuss how in-situ Raman spectroscopy can unravel the signatures of Li-ion induced doping, intercalation staging and degradation upon cycling.
(Keynote) Van Der Waals Active Metasurfaces and Heterostructures for Phase Modulation and Polarization Conversion
Authors: Atwater Harry
Published: July 2022

A grand challenge for nanophotonics is the realization of tunable metasurfaces enabling active control of the key constitutive properties of light – amplitude, phase, wavevector and polarization. Active metasurfaces that enable dynamic modulation of reflection amplitude, phase and polarization have been recently explored using several active materials and modulation phenomena, including carrier index in plasmonic ENZ structures, reorientation of liquid crystal molecules, electrooptic effects in quantum well heterostructures and index change in phase change materials. The rapid advances in understanding of exciton resonances in layered van der Waals materials has now stimulated thinking about active metasurfaces that exploit excitonic modulation phenomena to enable ‘van der Waals active metasurfaces’. As one example, I will describe recent advances in electrically reconfigurable polarization conversion across the telecommunication wavelength range in van der Waals layered materials, integrated in a Fabry-Pérot cavity. The large electrical tunability of the excitonic birefringence in tri-layer black phosphorus enables spectrally broadband polarization conversion over nearly half the Poincaré sphere. We observe both linear to circular and cross-polarization conversion with voltage, demonstrating dynamic access to polarization diversity. As a second example, we discuss the observed large gate tunability of the complex refractive index in monolayer MoSe2 by Fermi level modulation near the A and B excitonic resonances for temperatures between 4 K to 150 K. By tuning the charge density, we observe both temperature and carrier dependent epsilon-near-zero response in the permittivity and transition from metallic to dielectric near the A exciton energy, and directly observe active phase modulation in monolayer MoSe2 gated heterostructures, whose voltage dependence is consistent with our complex index measurements. These results have broad implications for the use of monolayer transition metal dichalcogenides in active metasurfaces, and I also will give a general outlook for the wide range of possibilities for active van der Waals metasurfaces.
(Invited) Controlling and Using Optoelectronic Properties of MoS2 and WS2 Monolayers
Authors: Miller-Link Elisa
Published: July 2022

Transition metal dichalcogenides (TMDCs) are an important class of materials because they can be reduced to 2D, where their quantum confined properties are easily manipulated for various applications. MoS2 is one of the most heavily studied TMDCs and is thermodynamically stable in the semiconducting 2H state. However, these monolayers are more catalytically active and have greater electron conductivity in the unstable, metallic (1T/1T’) state. Recently, we have demonstrated how to control the optoelectronic properties of MoS2 monolayers using n-butyl lithium immersion treatments and functional groups, where shorter treatment times heavily n-type dope MoS2 and longer treatment times fully convert the MoS2 from the semiconducting to metallic (1T/1T’) phase. By adding functional groups, the doped/converted MoS2 is stable for up to two weeks. In addition to MoS2, we have also explored how monolayers of semiconducting WS2 can be used as a contactless humidity sensor via photoluminescence. In this presentation, we will discuss the ways in which MoS2 and WS2 can be tuned for various optoelectronic properties.
High Energy Density Carbon Nanotube-Based Supercapacitors
Authors: Brahim Sean , Zhang Sanliang , Maat Stefan
Published: July 2022

We have developed supercapacitors utilizing electrodes made of binder-free carbon nanotube (CNT) / activated carbon (AC) composites. Due to the absence of organic binder our supercapacitors exhibit a significantly higher volumetric capacitance of ~20 F/cc compared to conventional supercapacitors while maintaining low resistance. This results in higher energy in the same package or smaller, more compact package size (lower volume) with same energy. Our cells pass 1,000 hour float tests at 2.7V between -35°C and 70°C, as well as high voltage operation at 3V and 70°C. Operation for 100,000 continuous cycles at 85°C was also achieved. Flat format supercapacitor pouch cells > 100 F have been demonstrated that can be integrated into automotive panels for autonomous power. Notable features of our CNT/AC composite supercapacitor technology include:

Scalable R2R coating of CNT/AC electrodes without additives. Option of water-based process with no solvent recovery

Binder-free CNT/AC electrodes provide 20% higher energy density than conventional AC-based electrodes (50% higher energy density at 3V)

CNT/AC supercapacitor technology is 100% packaging agnostic

Fabrication of 18650 EDLC cells rated at ~ 100 F demonstrated, and pouch cells rated at ~ 350 F demonstrated

The flat pouch-cell format allows installation in automotive panels as power sources for emergency door lock/unlock applications.

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(Invited) A Micelle Electrolyte Enabled By Fluorinated Ether Additives for Polysulfide Suppression, High Voltage Cathode, and Li Metal Anode Stabilization
Authors: Liu Gao
Published: July 2022

The Li-S battery is a promising next-generation technology due to its high theoretical energy density (2600 Wh/kg) and low active material cost. However, poor cycling stability and coulombic efficiency caused by polysulfide dissolution have proven to be major obstacles for a practical Li-S battery implementation. In this work, we develop a novel strategy to suppress polysulfide dissolution using hydrofluoroethers (HFEs) with bi-functional, amphiphlic surfactant-like design: a polar lithiophilic “head” attached to a fluorinated lithiophobic “tail.” A unique solvation mechanism is proposed for these solvents whereby dissociated lithium ions are readily coordinated with lithiophilic “head” to induce self-assembly into micelle-like complex structures. Complex formation is verified experimentally by changing the additive structure and concentration using small angle X-ray and neutron scattering. These HFE-based electrolytes are found to prevent polysulfide dissolution and to have excellent chemical compatibility with lithium metal: Li||Cu stripping/plating tests reveal high coulombic efficiency (>99.5%), modest polarization, and smooth surface morphology of the uniformly deposited lithium. Li-S cells are demonstrated with 1395 mAh/g initial capacity and 71.9% retention over 100 cycles at >99.5% efficiency—evidence that the micelle structure of the amphiphilic additives in HFEs can prohibit polysulfide dissolution while enabling facile Li+ transport and anode passivation. In addition, this type of electrolytes is also stable toward high voltage cathode to enable a lithium metal anode and high voltage cathode high-energy density rechargeable lithium battery.
Lithium Iron Phosphate Reconstruction Facilitates Kinetics in High-Areal-Capacity Sulfur Composite Cathodes
Authors: Gao Xiaosi , Zheng Changyang , Shao Yiqi , Jin Shuo , Suntivich Jin , Joo Yong Lak
Published: July 2022

Lithium-sulfur (Li-S) batteries have been recognized as one of the most promising choices beyond lithium-ion batteries (LIB), because of its low cost and high theoretical specific energy (~2510 Wh/kg or ~10 times of LIB). However, Li-S batteries still face a few challenges, including large volume expansion, poor conductivity, low active material loading, inert end products, and polysulfide crossover called the “shuttle effect”, etc.

To address these challenges, we have incorporated lithium iron phosphate (LFP) into our sulfur composite cathode. The addition of LFP enabled a more uniform slurry rheology, which allowed mass loading to double the amount of typical sulfur cathodes. Meanwhile, LFP can effectively adsorb polysulfides, which restricted the shuttle effects common in high-sulfur-loading batteries. Our LFP-hybrid Li-S batteries showed high areal capacity for 300 cycles under both low- and high-current charge-discharge cycles. More importantly, our characterizations demonstrated that LFP in Li-S batteries can reconstruct into Fe2P during cycling. We propose that Fe2P is an effective electrocatalyst for anchoring polysulfides.

To unveil the role of Fe2P, we have directly incorporated these materials into the sulfur composite cathode. Using a hydrothermal synthesis, we showed that Fe2P nanoparticles can be directly anchored on the sulfur-carbon composite. This approach caused minimal phase separation and enabled a uniform morphology. We presented the analysis of the cathodes by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These results allow us to develop a mechanistic hypothesis and a comparison between Fe2P and LFP in terms of the electrochemical performances.