bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Fuzzy Clustering with Deep Learning Models for Detection of COVID-19 Disinformation
Authors: Chen Mu-Yen , Lai Yi-Wei
Published: July 2022

Since the beginning of 2020, the COVID-19 pandemic has killed millions of people around the world, leading to a worldwide panic that has fueled the rapid and widespread dissemination of COVID-19-related disinformation on social media. The phenomenon, described by the World Health Organization (WHO) as an "indodemic" presents a serious challenge to governments and public health authorities, but the spread of misinformation has made human detection less efficient than the rate of spread. While there have been many studies developing automated detection techniques for COVID-19 fake news, the results often refer to high accuracy but rarely to model detection time. This research uses fuzzy theory to extract features and uses multiple deep learning model frameworks to detect Chinese and English COVID-19 misinformation. With the reduction of text features, the detection time of the model is significantly reduced, and the model accuracy does not drop excessively. This study designs two different feature extraction methods based on fuzzy classification and compares the results with different deep learning models. BiLSTM was found to provide the best detection results for COVID-19 misinformation by directly using deep learning models, with 99% accuracy in English and 86% accuracy in Chinese. Applying fuzzy clustering to English COVID-19 fake news data features maintains 99% accuracy while reducing detection time by 10%. For Chinese misinformation, detection time is reduced by 15% at the cost of an 8% drop in accuracy.
Law and Order
Authors: Cheesman Nick
Published: July 2022

Law and order denotes a negative form of peace secured among the members of a given social or political order. Minimally, it is an appeal to restore public order to conditions classed as disorderly, or to defend it against potential or articulated threats. But what counts as public disorder, and why is it a problem for any given social or political order? Although social and political scientists tend to concur that it is determined by tradition and convention, for some, the fact of disorder is sufficient for them to back projects for law enforcement and order maintenance. Others emphasize that facts about disorder are themselves socially made. Law and order is not a neutral category for interpretation of disorder, let alone for intervention. It is an ideological or discursive construct that itself warrants scrutiny. For still others, it is not just an element of ideology but a component in the technology of neoliberal government, which needs to be studied in terms of its functions and structural effects. And there are those who query whether law ought to be conjoined with order at all. They argue that no stable or necessary relation exists between the two and that the very idea of law and order is incongruous; that law and disorder or law or order is apposite.
Short-Lived Nuclides in the Early Solar System: Abundances, Origins, and Applications
Authors: Davis Andrew M.
Published: July 2022

Several short-lived radionuclides (SLRs) were present in the first few million years of Solar System history. Their abundances have profound impact on the timing of stellar nucleosynthesis events prior to Solar System formation, chronology of events in the early Solar System, early solar activity, heating of early-formed planetesimals, and chronology of planet formation. Isotopic analytical techniques have undergone dramatic improvements in the past decade, leading to tighter constraints on the levels of SLRs in the early Solar System and on the use of these nuclides for detailed chronological studies. This review emphasizes the abundances of SLRs when the Solar System formed and how we know them, and briefly discusses the origins of these nuclides and applications in planetary science.
(Invited) Single Walled Carbon Nanotube (SWNT) Atomic Structure and Thin Film Color during the Floating Catalyst Chemical Vapor Deposition (FC-CVD) Synthesis
Authors: Kauppinen Esko
Published: July 2022

We discuss the FC-CVD synthesis of SWNTs, especially the tuning of tube atomic structure i.e. (n,m) distributions and subsequently the thin film color. By introducing various amount of CO2 with CO as the carbon source and in-situ ferrocene decomposition generated Fe catalyst nanoparticles, we directly produced SWNT films with tunable (n,m) i.e. helicity distribution as well as tunable colors. When operating the FC-CVD reactor at the ambient pressure and at 850 oC temperature with 0.25 and 0.37 volume percent of added CO2, the SWNT films display green and brown colors, respectively. We ascribed various colors to suitable diameter and narrow (n,m) distributions, which were determined in detail using the electron diffraction. We calculate the color maps for all SWNT (n,m) structures.

N. Wei et al. Adv. Mater. 2021, 33, 2006395.
(Invited, Digital Presentation) Ultra-Low Thermal Conductance across Hetero-Structured Four-Layered Van Der Waals Materials
Authors: Yanagi Kazuhiro
Published: July 2022

Tuning the thermal properties of materials and exploring their heat transport mechanisms are of critical significance for optimizing the performance of current electronic and thermoelectric devices. Regarding flexible thermoelectric, recently, gigantic power factor is achieved in carbon nanotube fibers with tuned Fermi energy level [1]. Thus, control of heat transport across van der Waals (vdW) interfaces, which are the origins of flexibility, is very important for improvement of thermoelectric conversion efficiency. Considering that thermal transport is mainly affected by phonon-boundary scattering, development a route to tune such scattering at vdW interfaces is important. Ultrathin two-dimensional (2D) materials have been widely studied in electronic and photonic fields due to the distinctly unique geometrical and electronic structures of such materials. Regarding thermal transport properties, they have a lot of degrees of freedom in their integration, and the layered vdW integrated structure of these materials, in which building blocks are physically assembled together through weak vdW interactions, provides a strategy to reduce thermal conductance. The rich interfacial lattice mismatch in layered vdW structures is promising for enhancing phonon-boundary scattering at interfaces. For instance, Vaziri et al. studied the thermal boundary resistance of various heterointerfaces via the stacking of exfoliated several-micron-sized graphene, MoS2, and WSe2 monolayers using Raman thermometry, suggesting great potential for controlling heat flow by using the interfaces of vdW heterostructures [2]. However, there has been no systematic study on how homo- and hetero-interfaces with or without lattice matches influence heat flow. Therefore, a systematic study on the thermal conductance (G) of vdW structures with various comparable interfaces is urgently required to understand how homo- and heterointerfaces and the coupling effect influence thermal transport. Here we demonstrate the thermal conductance across four layered (4L) homo- and hetero-structured MoS2 and MoSe2 using time-domain thermo-reflectance method. Compared with the thermal conductance of homo-structured sample, the thermal conductance across hetero-structured 4L sample was significantly reduced, indicating that hetero-interface is an efficient way to reduce thermal conductance [3]. In addition, we have combined electrochemical gating method and TDTR measurements, and employed our technique on the 4L sample and investigated how the intercalation can influence the thermal conductance on the 4L sample. In this presentation, I would like to discuss our recent results.

References: [1] Komatsu et al. , Nature Comm. 12, 4931 (2021) [2] Vaziri et al. Sci. Adv. 5, eaax1325 (2019) [3] Yuan et al., ACS Nano 15, 15902 (2021)

Figure 1
(Invited, Digital Presentation) Composites of 2D Materials and Organic Molecules
Authors: Umeyama Tomokazu
Published: July 2022

Atomically thin two-dimensional (2D) materials have aroused an explosive growth of scientific interest for their outstanding physicochemical properties. In addition, decorations of 2D materials with organic semiconductors have also begun to receive scientific attention owing to the tunable optoelectronic properties and the excellent solution-based processability of the organic molecules. In this study, composite films that consisted of C60 with well-exfoliated nanosheets of transition metal dichalcogenides (TMDs) [1], antimony [2], or bismuth [3] were successfully fabricated onto a semiconducting SnO2 electrode via a two-step methodology: self-assembly into their composite aggregates by injection of a poor solvent into a good solvent with the dispersion, and subsequent electrophoretic deposition. In addition, photophysical and photoelectrochemical properties of the composite films were investigated in detail. For example, in a flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurement of a composite material consisting of C60 and few-layered antimonene (FLSb) nanosheets (denoted as (FLSb+C60)
m
), a rapid rise in transient conductivity was observed, whereas no conductivity signal was observed in the single components, FLSb and C60. This demonstrated the occurrence of photoinduced charge separation between FLSb and C60 in (FLSb+C60)
m
. Furthermore, a photoelectrochemical device with an electrophoretically deposited (FLSb+C60)
m
film exhibited an enhanced efficiency of photocurrent generation, compared to those of the single-components, FLSb and C60, due to the photoinduced charge separation between FLSb and C60. This work provides a promising approach for fabrication of 2D material–organic molecule composites and paves the way for their application in optoelectronics.

[1] J. Baek, T. Umeyama, W. Choi, Y. Tsutsui, H. Yamada, S. Seki, and H. Imahori, Chem. Eur. J., 24, 1561-1572 (2018).

[2] T. Umeyama, T. Ohara, Y. Tsutsui, S. Nakano, S. Seki, and H. Imahori, Chem. Eur. J., 26, 6726-6735 (2020).

[3] T. Umeyama, H. Xu, T. Ohara, Y. Tsutsui, S. Seki, and H. Imahori, J. Phys. Chem. C, 125, 13954-13962 (2021).
(Invited) Ligand-Protected Metal Nanoclusters: Recent Development in Synthesis and Application in Energy and Environmental Field
Authors: Negishi Yuichi
Published: July 2022

Metal nanoclusters (NCs), which are composed of about 250 or fewer metal atoms, possess great potential as novel functional materials. Fundamental research on metal NCs gradually started in the 1960s, and since 2000, thiolate (SR)-protected metal NCs have been the main metal NCs actively studied. The precise and systematic isolation of SR-protected metal NCs has been achieved in 2005. Since then, research on SR-protected metal NCs for both basic science and practical application has rapidly expanded. This presentation demonstrates our recent study on alloy NCs, connected structures composed of NCs, the applications of NCs in the energy and environmental field. This presentation provides insight on the current state of research on SR-protected metal NCs and discusses the challenges to be overcome for further development in this field as well as the possibilities that these materials can contribute to solving the problems facing modern society.

Figure 1
Three-Dimensional Carbon Foam Based Asymmetric Assembly of Metal Oxides Electrodes for High-Performance Solid-State Micro-Supercapacitor
Authors: Kumar Sumana , Misra Abha
Published: July 2022

Micro-supercapacitors hold great attention as one of the promising energy storage devices satisfying the increasing quest for miniaturized and portable devices. Despite having impressive power density, superior cyclic lifetime, and high charge-discharge rates, micro-supercapacitors still suffer from low energy density, limits their practical application. The energy density (E=1/2CV2) can be increased either by increasing specific capacitance (C) or voltage range (V). Asymmetric micro-supercapacitors have attracted great attention by using two different electrode materials to expand the voltage window and thus increase the energy density. Currently, versatile fabrication technologies such as inkjet printing, lithography, laser scribing, etc., are used to directly or indirectly pattern the electrode material; these techniques still suffer from scalable production and cost inefficiency. Here, we demonstrate the scalable production of a three-dimensional (3D) carbon foam (CF) based asymmetric micro-supercapacitor by spray printing technique on an array of interdigital electrodes. The solid-state asymmetric micro-supercapacitor comprised of CF-MnO positive electrode and CF-Fe2O3 negative electrode achieves a high areal capacitance of 18.4 mF/cm2 (2326.8 mF/cm3) at 5 mV/s and a wider potential window of 1.4 V. Consequently, a superior energy density of 5 µWh/cm2 is obtained, and high cyclic stability is confirmed with retention of the initial capacitance by 86.1% after 10000 electrochemical cycles. The optimized decoration of pseudocapacitive metal oxides in the 3D carbon network helps in high electrochemical utilization of materials where the 3D interconnected network of carbon provides overall electrical conductivity and structural integrity. The research provides a simple and scalable spray printing method to fabricate an asymmetric micro-supercapacitor using a custom-made mask that can be integrated on a large scale.
(Digital Presentation) Elucidating the Charge Storage Mechanism on Ti3C2 MXene through in-Situ/Operando Raman Spectroelectrochemistry
Authors: Johnson Denis , Hansen Kyle , Lai Hao En , Balbuena Perla B. , Djire Abdoulaye
Published: July 2022

Current climate issues we face can be partially remedied through the inclusion of renewable energy sources. However, these energy sources suffer from the need for highly efficient energy storage systems. To this end, studies have been conducted on developing energy storage materials that can provide high energy and power densities. Two-dimensional (2D) carbide and nitride MXenes have the potential to provide both if their mechanism of charge storage is known. Here, we use in-situ/operando Raman spectroelectrochemistry to investigate the charge storage mechanism of the benchmark Ti3C2 MXene in acidic and neutral media (0.1M HCl and 0.5M NaSO4, respectively). We found that overcharging of the MXene electrode occurs during electrochemical charging, which draws positively charged ions towards the MXene’s surface to enable a pseudocapacitive process or Faradaic redox process. The material then undergoes reversible redox processes accompanied by reversible structural changes within its stable voltage window during electrochemical charge storage. I will show density functional theory (DFT) calculation results that corroborate these findings. Ultimately, these fundamental insights can be used to design electrode materials with both high energy and power densities.
Magnesium- and Tin-Based Ionic Liquid Electrolytes for Advanced Multivalent Metal Batteries
Authors: Pagot Gioele , Kieser Joy , Brombin Federico , Vezzu Keti , Lorandi Francesca , Negro Enrico , Janek Jürgen , Di Noto Vito
Published: July 2022

In the recent years, the global energy economy is experiencing a transition towards its production from more sustainable and “green” sources. The intrinsic characteristics of these methods, such as the intermittency and misalignment between disposability and demand, require the use of energy storage systems, such as secondary batteries. Despite the high performance of Li-ion batteries, the high cost, low abundance and toxicity of their components (e.g., the Co-based cathodes) request the development of new devices based on novel chemistries. In this regard, the holy grail is the production of battery systems based on abundant multivalent metals.

It has been recently demonstrated that ionic liquids (ILs) are suitable solvents in order to obtain stable and high performing electrolytes able to conduct and deposit/strip multivalent metals [1-5]. The outstanding electrochemical properties of these materials are ensured by the presence of a high-reactive magnesium salt (i.e., the “delta” form of MgCl2) and of a suitable metal halide (e.g., AlCl3, TiCl4, etc.). In this project we have developed a family of IL-based electrolytes for the Mg2+ ion conduction doped with an alkyl tin halide compound. In this way, the hybrid chemico-physical properties of Sn-based species can be exploited to improve the coordination existing between the inorganic magnesium salt and the organic IL. An advanced study on the thermal and structural properties of the proposed material will be presented, with a particular focus on the interactions established between the different chemical species and complexes composing the materials. Insights on the conductivity mechanism occurring in a wide range of temperature will be gauged and thoroughly described by means of the broadband electrical spectroscopy studies.

Acknowledgments

The project “Interplay between structure, properties, relaxations and conductivity mechanism in new electrolytes for secondary Magnesium batteries” (Grant Agreement W911NF-21-1-0347-(78622-CH-INT)) of the U.S. Army Research Office. The project “ACHILLES” (prot. BIRD219831) of the University of Padua. The project “VIDICAT” (Grant Agreement 829145) of the FET-Open call of Horizion 2020.

References

[1] G. Pagot, K. Vezzù, S. Greenbaum and V. Di Noto, Journal of Power Sources 492 (2021) 229681.

[2] R. Dominko, J. Bitenc, R. Berthelot, M. Gauthier, G. Pagot and V. Di Noto, Journal of Power Sources 478 (2020) 229027.

[3] G. Pagot, F. Bertasi, K. Vezzù, F. Sepehr, X. Luo, G. Nawn, E. Negro, S.J. Paddison and V. Di Noto, Electrochimica Acta 246 (2017) 914-923.

[4] F. Bertasi, F. Sepehr, G. Pagot, S.J. Paddison and V. Di Noto, Advanced Functional Materials 26 (2016) 4860-4865.

[5] F. Bertasi, C. Hettige, F. Sepehr, X. Bogle, G. Pagot, K. Vezzù, E. Negro, S.J. Paddison, S.G. Greenbaum, M. Vittadello and V. Di Noto, ChemSusChem 8 (2015) 3069-3076.
Electrochemically Rechargeable Liquids in Highly Flexible Energy Storage Systems
Authors: Perry Mike L
Published: July 2022

Hydrogen and electricity are expected to be the two major energy carriers of the future. Unfortunately, neither can be stored as an ambient-temperature liquid, which is the ideal energy-carrier medium. H2 can be used in a wide variety of both stationary and transportation applications, as envisioned by DOE’s H2@Scale program [1]. Although DOE has not yet established targets for stationary H2 storage, the key metrics for an “ideal hydrogen carrier” are [2]: liquid at all operating temperatures, high energy density, efficient conversions at relatively benign conditions, long cycle life, compatible with existing infrastructure for fuels, low cost, and safety (toxicological and eco-toxicological). Relative to thermal conversions, electrochemistry can enable relatively efficient conversions at more benign conditions. While electrochemically-rechargeable liquids (ERLs) are not a new idea, the focus of this talk will be on innovative conversion options, which includes combinations of the cell configurations shown in Fig. 1. In particular, it will be shown that ERLs that can be charged using either electrical and/or hydrogen energy, and which can also produce H2 or electricity on demand can enable highly flexible energy-storage systems that can potentially be used for both stationary and transportation applications. In short, an ERL can provide essential “energy-banker services” by simultaneously converting and storing these two major “energy currencies” of the future in a single aqueous liquid. These systems can be readily scaled up or scaled down. This talk will also present a very brief overview of potentially attractive ERL options, which can include conventional liquid-organic hydrogen carriers (i.e., LOHCs, such as organics that are liquids at room temperature, like methylcyclohexane), as well as aqueous solutions (e.g., diluted alcohols) or dissolved solids (e.g., redox-flow-battery electrolytes) [3]. The current status of this technology will be briefly reviewed, including a summary the key technical barriers, as well as some enabling concepts to potentially address each of these challenges.

The goal will be to provide the audience with a sufficient overview of these ERL-conversion system concepts, such that a productive discussion can occur on additional improvements, potential end uses, and future collaborations.

[1] B. Pivovar, N. Rustagi, and S. Satyapal, ECS Interface,
27 (2018) 47.

[2] T. Autry and M. Bowden, “HyMARC; H2 Carriers for Bulk H2 Storage & Transport,” AMR slides, ST204 (2020).

[3] M. L. Perry & Z. Yang, J. Electrochem. Soc., 166 (2019) A3045.

Figure 1
Exploring Charged Defects and Dopability Limits of Solid Electrolytes, a Computational Study
Authors: Benabed Yasmine , Dahliah Diana , Dolle Mickael , Hautier Geoffroy
Published: July 2022

All-Solid-State Lithium Batteries (ASSLBs) are a new generation of lithium batteries that is developed to meet high expectations in terms of safety, stability and high energy density. The liquid electrolyte of conventional Li-ion batteries is replaced in ASSLBs by a safer and more stable solid electrolyte (SE). These solid electrolytes must meet a number of requirements before they can be considered in ASSLBs, including a wide electrochemical stability window, a high ionic conductivity and a negligible electronic conductivity [1]. For a long time, researchers have focused on achieving the highest ionic conductivity possible on these materials, comparable to the one of liquid electrolytes. The ionic conductivity in SEs has been successfully increased by the introduction of defects (doping) and Li1.3Al0.3Ti1.7(PO4)3 and Li1.5Al0.5Ge1.5(PO4)3 solid electrolytes are both excellent examples of such achievement. However, the formation of defects can also have a significant effect on the SEs electronic conductivity [2],[
3],[
4]. Increasing the electronic conductivity in solid electrolytes is detrimental to the ASSLBs safety and integrity. Therefore, it is essential to understand the defect chemistry in SEs. Due to their negligible concentration, characterizing point defects is hardly possible using standard characterization techniques, justifying the need for first-principles calculations. In this work, we have investigated the defect chemistry of most common solid electrolytes (LixM2(PO4)3 (M = Zr, Ti, Ge, Al), Li7La3Zr2O12, LiLaTi2O6, Li10Ge(PS6)2, Li7P3S11, Li3PS4, Li3PO4 and LiPO3). For each SE, we computed the formation energies for intrinsic defects and assessed the dopability limits as a function of the synthesis conditions. We found that the position of the Fermi level and dopability limits depend strongly on lithium and oxygen/sulfur chemical potentials but also on the nature of the solid electrolyte. We advocate that it is imperative to better regulate the synthesis conditions if we want to gain control over the formation of defects in solid electrolytes. The outcoming properties of these materials, such as the ionic and electronic conductivities, depend on it.

[1] N. Dudney. Springer. 2003, 624-642. [2] E. Zhao et al.
J. Alloys Comp. 2019. 782, 384-391. [3] Y. Song et al. J. Mat. Chem. A. 2019, 7(40), 22898-22902. [4] Y. Shan et al. J. Power Sources. 1995, 54(2), 397-402.
Formation of Mn-Zn Layered Double Hydroxide - New Insights into the Charge Storage Mechanism of Near-Neutral MnO2/Zn Batteries
Authors: Stosevski Ivan , Bonakdarpour Arman , Fang Baizeng , Wilkinson David P.
Published: July 2022

A relatively new type of aqueous battery that is based on MnO2/Zn chemistry in near-neutral pH electrolytes is receiving significant attention in the research community for its potential commercial applications. This chemistry offers many advantages such as relatively high cycle life [1], low cost, high natural abundance and availability of the active materials, and environmental friendliness. On the other hand, issues with the formation of parasitic Zn-layered double hydroxide (ZnLDH) creates challenges for the capacity utilization in high mass loading electrodes. Revealing the charge storage mechanism and the products of the discharge reaction would significantly help with the scaling up of this technology.

At present, there is a debate on the nature of the reaction mechanism considering proton or zinc intercalation (or co-insertion of both) into the MnO2 structure, and what structural transformations occur during charge/discharge. We present new insights on the reaction mechanism and show that novel, not reported yet, Mn-Zn based layered double hydroxide (MnZnLDH, MnxZny(OH)zSO4

·

5H2O) forms during the first discharge reaction (Figure 1) [2]. MnZnLDH forms through a conversion reaction that occurs between MnO2 and Zn2+ during the first discharge plateau and it is a structural analogue of ZnLDH. Electrochemical experiments in different aqueous/organic electrolytes with and without the presence of Zn ions have shown that protons and water play significant roles in the charge-storage mechanism, while Zn ions form species at the surface rather than intercalating in the bulk of MnO2 structure. Excellent rechargeability was achieved for the ramsdellite (MnO2) and hausmannite (Mn3O4) phases, i.e., over 1000 [1] and 800 [3] cycles, respectively, without considering the formation of MnZnLDH. However, improving the reversibility of MnZnLDH transformation during the cycling will enhance the battery cycle life even further.

References

[1] I. Stoševski, A. Bonakdarpour, F. Cuadra, & D. P. Wilkinson, Chem. Comm., 2019, 55, 2082-2085.

[2] I. Stoševski, A. Bonakdarpour, B. Fang, P. Lo, & D. P. Wilkinson, Electrochim. Acta, 2021, 390, 138852.

[3] I. Stoševski, A. Bonakdarpour, B. Fang, S. T. Voon, & D. P. Wilkinson, Int. J. Energy Res., 2021, 45, 220-230.

Figure 1. Mechanism of the first discharge reaction

Figure 1
Halogen Conversion-Intercalation Cathode for Zinc-Ion Battery
Authors: Ejigu Andinet , Dryfe Robert , Le Fevre Lewis
Published: July 2022

Zinc-ion batteries (ZIBs) are a promising class of batteries for grid-scale electrochemical energy storage owing to their low cost, easy fabrication and high operational safety. ZIBs adoption have been hampered by a lack of efficient cathode materials, which is due to the high polarisation of divalent zinc ions, which leads to strong binding with the host lattice in combination with slow solid-state migration. In this contribution, I describe a strategy that eliminates the involvement of Zn2+ within cathode chemistry. The method employs confined halogen within a carbon structure as the cathode electrode, with the halogen ions acting as both charge carriers and redox centres. The benefits of using confined halogen within the carbon structure as a cathode are (i) elimination of the irreversible binding of Zn2+ to the host structure within the cathode chemistry, (ii) the provision of substantial extra charge through their conversion-intercalation/adsorption process and (iii) they do not have to diffuse to the surface from bulk electrolyte as they are already inside the carbon structure aqueous ZIBs that utilize a conversion chemistry cathode. I'll illustrate how the cathode composite's Zn halide and carbon structure are completely different, resulting in electrochemical energy storage devices that are fundamentally different (battery vs supercapacitor). The use of graphite in the composite electrode resulted in battery-like behaviour, with the voltage plateau being related to the halogen species' standard potential. Using a mix of electrochemical and in-situ spectroscopic approaches, the halogen reaction process was revealed. This fundamental understanding will be used as a starting point for the development of efficient aqueous ZIBs that utilize a conversion chemistry cathode.
(Invited) Evaporable Fullerene-Fused Ketone Via One-Step Direct Oxidation of Alkoxy to Ketone: Fullerene As a Redox Active Pendant
Authors: Matsuo Yutaka , Lin Hao-Sheng
Published: July 2022

We developed a direct oxidation reaction from a methoxy group to a keto group using a mild oxidizing agent with the aid of an oxidizable fullerene pendant. By using this key reaction, we developed a fullerene derivative that is stable even at high temperatures of 400 deg-C or higher and can be used for vacuum deposition to make thin films in organic electronic devices.

A highly efficient CuBr2 promoted one-step direct oxidation of alkoxy indano[60]fullerenes to [60]fullerene-fused ketones is showcased. It is shown that the fullerene can behave as an electron-pool controlling the electron transfer to trigger the direct oxidation of alkoxy. This electron-pool for the direct oxidation mainly involves two steps: 1) C60selectively transferred single electron to Cu(II) to afford C60
•+; 2) generated C60
•+ attracts electron density from the neighboring C–H bond, which is the key for initiating the direct oxidation of alkoxy. Accordingly, conventional non-fullerene functionalized alkoxy groups understandably failed to undergo one-step direct oxidation. Encouragingly, compared with current synthetic protocols for fullerenyl ketones including electrochemical synthesis, organometal-catalyzed synthesis, and photochemical synthesis, the presented one-step direct oxidation of alkoxy exhibited advantages such as facile processing procedures, highly scalable yields and low cost, for the efficient production of [60]fullerene-fused ketones, which can provide an efficient synthetic strategy to match up the high synthetic demands of fullerenyl ketone materials applied in organic and perovskite solar cells.

Reference: H.-S. Lin, Y. Ma, R. Xiang, S. Manzhos, I. Jeon, S. Maruyama, Y. Matsuo, Communications Chemistry 2021, 4, 74.
(Invited) Fullerene and Fullerene Nanocomposites for an Enhanced All-Vanadium Redox Flow Battery
Authors: El Diwany Farah , Al Najjar Taher , Ali Basant , K. Allam Nageh , El Sawy Ehab
Published: July 2022

The dependence on fossil fuels to meet the world energy demand caused several social, economical, and environmental problems. An immediate switch to sustainable, clean, and renewable sources of energy is a necessity. To achieve this switch, developing efficient technologies to convert renewable energy sources into electricity is a necessity but not enough due to the intermittent behavior of renewable sources. The incorporation of energy storage systems as regulators allows for the sustainable integration of renewable energy resources into the electrical grid. Vanadium redox flow batteries (VRFBs) are the most promising candidates of the currently available energy storage technologies, as they have an unlimited capacity (theoretically) and design flexibility. Enhancing the kinetics of the VRFBs electrochemical reactions will enhance their energy efficiency, and hence decrease the kWh cost of VRFBs. Currently, carbon-based electrodes are employed due to their suitable stability and conductivity, but with no treatment, they suffer from sluggish kinetics, hydrophobicity, and parasitic reactions catalyzation.1 Modifying these carbon-based electrodes with carbon nanostructures2 and metal oxides(MOx)3 was found to enhance the kinetics at the VRFB electrodes.

Even though fullerenes have very unique structural and chemical properties they were rarely explored for the VRFBs application.4 In this work, fullerene C76 showed superior electrocatalytic activity towards VO2+/VO2
+ redox reaction in G1 and G3 VRFBs and eliminated the necessity for thermal treatment of the carbon cloth support while inhibiting the chlorine evolution in G3 VRFB. A composite of C76 and hydrated WOx that reduces the fullerene content to half further inhibited the chance for chlorine evolution while maintaining the catalytic activity.

References:

Y. Gao et al., Carbon, 148, 9–15 (2019).

D. O. Opar, R. Nankya, J. Lee, and H. Jung, Electrochimica Acta, 330, 135276 (2020).

M. Faraji, R. Khalilzadeh Soltanahmadi, S. Seyfi, B. Mostafavi Bavani, and H. Mohammadzadeh Aydisheh, J Solid State Electrochem, 24, 2315–2324 (2020).

F. A. E. Diwany, B. A. Ali, E. N. E. Sawy, and N. K. Allam, Chem. Commun., 56, 7569–7572 (2020).
(Invited) Dynamics of Porphyrin-Fullerene Charge Transfer and Recombination Via Ultrafast Spectroscopy
Authors: Kopcha William , Harrell Jaren , Piotrowiak Piotr , Zhang Jianyuan
Published: July 2022

Electron donor-acceptor (D-A) interactions have been the subject of intense scrutiny by the scientific community due to their role in a variety of applications, such as solar energy production, photocatalysis, and stimulus-responsive materials. We chose porphyrins and fullerenes for our fundamental studies of D-A interactions, as they are the prototypical D-A pair by virtue of their well-positioned energy levels, low reorganization energies, and the high extinction coefficients of the porphyrin ring in the visible region. Moreover, they give us the opportunity to not only choose between different bound or endohedral metal ions or clusters, but also to connect them in different ways in order to tune their behavior. We have used time-resolved spectroscopic techniques, including transient absorption, fluorescence upconversion, and time-correlated single-photon counting, to untangle charge separation and recombination dynamics upon donor excitation in the femto- to nanosecond regime to gain additional insight into the relationship between structure and behavior.
(Invited) Porphyrinoid-Carbon Nanostructure Ensembles and Fused Porphyrin-Graphene Nanoribbons
Authors: Torres Tomas , López-Serrano Elisa , Gomez-Gomez Marta , Mateo Luis M. , Labella Jorge , Bottari Giovanni , Ince Mine
Published: July 2022

Phthalocyanines (Pcs) have emerged as excellent light harvesting antennas for incorporation into D-A systems, mainly in connection with carbon nanostructures, like endohedral metallofullerenes, SWCNT and graphene, as acceptor or donor moieties, in which the Pc has been attached, covalently or through supramolecular interactions. They are among the few molecules that reveal an intense red and NIR absorption and therefore, constitute also promising dyes in molecular photovoltaics. Pcs have a great chemical versatility, which allows to modify their electronic character and their physicochemical properties by organic synthesis, by introducing substituents in the periphery or modifying the structure of the macrocycle. Most recently they have reached good efficiency values participating as hole transporting materials in Carbon-based Perovskite sensitized solar cells (PSSCs). Pcs are be appropriately designed to adapt well to the electronic levels of the different types of perovskites. Through a rational design, structure-property relationships will be established that will gradually improve the performance of the devices.

On the other hand, on-surface synthesis offers a versatile approach to fabricate novel carbon-based nanostructures that cannot be obtained via conventional solution chemistry. Within the family of such nanomaterials, graphene nanoribbons (GNRs) hold a privileged position due to their high potential for different applications. One of the key issues for their application in molecular electronics lies in the fine-tuning of their electronic properties through structural modifications, such as heteroatom doping or the incorporation of non-benzenoid rings. In this context, the covalent fusion of GNRs and porphyrins (Pors) represents a highly appealing strategy.
(Invited) Pressure-Induced New Carbon Materials with New Properties
Authors: Yao Mingguang
Published: July 2022

Design and synthesis of new carbon materials have been attracting intensive attention due to their application in various fields. The study of carbon nanostructures under high pressure provides us a very effective method to create new carbon material which is hardly discovered at ambient conditions because of the appearance of nanometer scale size effect and the novel high pressure behavior. In this presentation, several examples on high pressure induced novel structures in recently studied fullerene based molecular cocrystals will be outlined. Particularly, anomalous negative volume compressibility observed in the eutectic Sc3N@C80 -cubane crystal under high pressure will be introduced. The charge transfer from fullerene cage to cubane promotes the configuration change of cubane, which transforms into a “low density” configuration, resulting in an abnormal lattice expansion of the crystal. This is the first experimentally discovered crystal which has negative volume compressibility. We will also present the synthesis of nearly all sp3 amorphous carbon bulk material from high temperature and high pressure (HPHT)-treated C60 for the first time. This new sp3 amorphous carbon material shows an optical band gap of ~2.7eV and extremely high Vickers hardness of 102 GPa under 9.8N load, close to that of diamond, which is a multifunctional superhard amorphous carbon material with the highest thermal conductivity and hardness known in the amorphous materials up to now.
(Digital Presentation) In-Situ Oxygen Functionalization of Titanium Carbonitride MXene for Enhanced Water Splitting
Authors: Uwadiunor Ekenedilichukwu , Djire Abdoulaye
Published: July 2022

Two-dimensional (2D) carbide and nitride MXenes possess properties that are desirable for a broad range of electrocatalytic applications including hydrogen evolution reaction (HER). These properties include high surface area, hydrophilicity, heterogeneity of redox-active transition metals, and tunable surface functionalities allowing for low HER overpotentials. In this presentation, I will report on the -O functionalization of Ti3CNTx (Tx = -O, -F, -OH) upon the application of external potential for improved HER performance and show that the active sites for HER on this MXene catalyst are located primarily on the O functional groups. The overpotential for the Ti3CN improves by 350 mV upon in-situ -O functionalization and reaches -0.46 V vs. RHE at a current density of 10 mA cm-2. Structural and electrochemical characterization results showed that the functionalized Ti3CNTx MXene catalyst is structural and electrochemically stable. Further insights into the mechanism of HER were provided by in-situ/operando Raman spectroelectrochemistry and the results will be presented. Ultimately, these findings provide a path forward to tuning the electrocatalytic activity of MXenes and related electrocatalysts for water splitting.
A Simple Micropreparative Gel Electrophoresis Technique for Purification of Nanoscale Materials
Authors: Sajjadi Sayyed Hashem , Wu Shang-Jung , Zubkovs Vitalijs , Ahmadzadeh Hossein , K. Goharshadi Elaheh , Boghossian Ardemis Anoush
Published: July 2022

Many biochemical, biomedical, and material applications hinge on the ability to effectively separate and purify nanoscale materials. Though this need is largely addressed with biological macromolecules using a variety of chromatographic and electrophoretic purification techniques, such techniques are usually laborious, time-consuming, and often require complex and costly instalments that are inaccessible to most laboratories. Synthetic nanoparticles face similar purification challenges, often relying on techniques that are material-specific. In this work, we introduce a versatile micro-preparative (MP) method based on polyacrylamide gel electrophoresis (PAGE) to purify biological samples containing proteins, nucleic acids, and complex bioconjugates, as well as synthetic nanoparticles based on graphene quantum dots (GQDs). Using a conventional vertical slab PAGE, we demonstrate the extraction of purified DNA, proteins, and DNA-protein bioconjugates from their respective mixtures using MP-PAGE. We apply this system to recover DNA from a ladder mixture with yields of up to 90%, compared to the 58% yield obtained using specialized commercial devices. We also demonstrate the purification of folded enhanced yellow fluorescence protein (EYFP) from crude cell extract with 90% purity, comparable to purities achieved using a two-step size exclusion and immobilized metal-ion affinity chromatography purification procedure. Moreover, we demonstrate the successful isolation of an EYFP-DNA bioconjugate that otherwise could not be processed using the two-step chromatography procedure. Finally, the technique was further extended to demonstrate size-dependent separation of a commercial mixture of GQDs into three different fractions with distinct optical properties. MP-PAGE thus offers a rapid and versatile means of purifying biological and synthetic nanomaterials without the need for specialized equipment.
(Invited) Stabilizing and Enhancing Lithium-Ion Batteries with Chemically Inert 2D Materials
Authors: Hersam Mark C
Published: July 2022

Efficient energy storage systems represent a critical technology across many sectors including consumer electronics, electrified transportation, and a smart grid accommodating intermittent renewable energy sources. Arguably, the most important advance in energy storage over the past three decades is the lithium-ion battery, which was recently recognized with the Nobel Prize in Chemistry. However, despite its many successes, issues related to safety, energy density, charging time, and operating temperature range have hindered the realization of the full potential of lithium-ion battery technology, particularly in large-scale applications such as grid-level storage and full electrification of transportation networks. Nanostructured materials were once thought to present compelling opportunities for next-generation lithium-ion batteries, but inherent problems related to high surface area to volume ratios at the nanometer-scale (e.g., undesirable surface chemical interactions between electrodes and electrolytes) have impeded their adoption for commercial applications. This talk will explore how the chemical inertness of select two-dimensional (2D) materials are driving a resurgence in nanostructured lithium-ion battery materials [1]. For example, conformal graphene coatings on lithium-ion battery cathode powders mitigate surface degradation and minimize the formation of the solid electrolyte interphase, thus improving cycling stability [2]. In addition, the high electrical conductivity of graphene reduces cell impedance, resulting in enhanced kinetics that enable high-rate capability and low-temperature performance down to –20 °C [3]. On the other hand, ionogel electrolytes based on ionic liquids and hexagonal boron nitride (hBN) nanoplatelets provide safe, high-rate operation at high temperatures up to 175 °C, which represents the highest operating temperature to date for solid-state lithium-ion batteries [4,5]. The strong interfacial interactions between hBN and ionic liquids further enable novel electrolyte architectures based on layered heterostructure ionogels that result in unprecedently high energy densities and rate performance for solid-state batteries [6].

[1] H. Bergeron, et al., Chemical Reviews, 121, 2713 (2021).

[2] K.-Y. Park, et al., Advanced Energy Materials, 10, 2001216 (2020).

[3] K.-Y. Park, et al., Advanced Materials, DOI: 10.1002/adma.202106402 (2021).

[4] W. J. Hyun, et al., ACS Nano, 13, 9664 (2019).

[5] W. J. Hyun, et al., Advanced Energy Materials, 10, 2002135 (2020).

[6] W. J. Hyun, et al., Advanced Materials, 33, 2007864 (2021).
Photophysical Properties and Imaging of Exfoliated Near Infrared Fluorescent CaCuSi4O10 Nanosheets
Authors: Kruss Sebastian
Published: July 2022

Imaging in the near infrared (NIR) range of the spectrum is beneficial due to reduced light scattering, absorption, toxicity and autofluorescence. However, there are only few near infrared fluorescent materials known and suitable for biomedical applications. Here, we exfoliate the near infrared fluorescent layered pigment CaCuSi4O10 (known as Egyptian Blue, EB) v
ia different mechanical and chemical approaches into nanosheets (EB-NS) of high monodispersity. Dimensions of the nanosheets decrease with sonication time < 10 nm down to single EB layers (around 1 nm). The near infrared fluorescence of EB at 910 nm is retained in EB-NS and the total fluorescence intensity scales with size. Furthermore, we demonstrate that EB-NS display ultra-high photostability (no bleaching), are extremely bright compared to other NIR fluorophores and can be used for lifetime encoded imaging. We also show that the fluorescence lifetimes in the µs range depend on particle size and can be used to enhance contrast in imaging. In summary, we introduce exfoliated 2D CaCuSi4O10 nanosheets as versatile NIR material for biophotonics.
(Invited, Digital Presentation) Single-Atom Quantum Magnetism in 2D Materials
Authors: Villarreal Renan
Published: July 2022

With the advent of 2D materials, the playground to study spins in dilute and non-dilute phases has expanded. This is appealing for utilizing the additional degrees of freedom of electron systems such as spin and valley and, from the fundamental point of view, to better understand atomic scale magnetic phenomena in low dimensional materials. Dilute magnetism in 2D materials can lead to complex magnetic phenomena (e.g., Kondo effect, RKKY-interactions, quantum relaxation and coherence), with potential for applications in spintronics (e.g., spin FETs) and quantum technologies (e.g., single-atom quantum memories). We are investigating how to selectively incorporate substitutional magnetic atoms (3d transition metals and 4f rare earths) in 2D materials, using ultra low energy ion implantation, and we characterize their structural, electronic, and magnetic properties [1]. Ultra-low energy (ULE) ion implantation allows us to precisely tune the kinetic energy of the ions, providing control over the form of incorporation and concentration while preserving the structural and electronic properties of graphene. Our approach is based on a wide range of characterization techniques (structural and electronic), including scanning tunneling microscopy and spectroscopy (STM/STS), Raman spectroscopy, synchrotron-based X-ray photoelectron spectroscopy (XPS), angle-resolved photoemission spectroscopy (ARPES), X-ray magnetic circular dichroism (XMCD), among others. These experimental studies are complemented by density functional theory (DFT) and molecular dynamics (MD) simulations. The new insights provided by our work establish a framework for the controlled incorporation of magnetic dopants in 2D materials, using ULE ion implantation.

[1] P. C. Lin et al., ACS Nano 15(3), 5449-5458 (2021).