bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Bodipy-Nanocarbon Hybrids for Mimicking Early Events of Natural Photosynthesis
Authors: D'Souza Francis 
Published: February 2020

Mimicking the early events of natural photosynthesis, and utilizing that information to build energy harvesting devices is considered one of the avenues to tap into the vast amount of solar energy. Research performed on this topic by scientists across the globe has been highly promising and has strengthened our fundamental understanding of natural and artificial photosynthesis. In the process of mimicking the early events of photosynthesis, excitation transfer and electron transfer in a sequential fashion, similar to what happens in the antenna and reaction centre of natural photosynthesis, are deemed to be of paramount interest. Accordingly, supramolecular donor-acceptor systems capable of performing these photo processes are considered very important. Although several donor-acceptor systems are known to undergo either energy transfer or electron transfer or simultaneous occurrence of these two photo processes in competition upon photoexcitation, there are not many systems where energy transfer and electron transfer in a sequential route have been reported.
Nanocarbons such as fullerenes, single wall carbon nanotubes, graphene oxide, and graphene have been widely used in the construction of such multi-modular donor-acceptor systems. Porphyrins and phthalocyanines are class of widely used photosensitizers. In recent years, application BF2-chelated dipyrromethene (BODIPY) and BF2-chealted azadipyrromethene (azaBODIPYs), in building artificial photosynthetic models have witnessed a rapid growth. This is primarily due to the synthetic versatility of these sensitizers to couple with nanocarbons to modulate their photo- and redox properties to promote efficient photoinduced energy and electron transfer processes. In few instances, accomplishing the combined ‘antenna-reaction center’ functionality of photosynthesis has been possible. The present contribution summarizes recent progress made in our laboratory in this area of research.
(Invited) Gas-Phase Clusterfullerene Doping and Exohedral Modification By Laser-Based Methods
Authors: Dunk Paul W. , Mulet-Gas Marc , Marshall Alan G. , Hendrickson Christopher L. , Castro Edison , Echegoyen Luis , Abella Laura , Moreno-Vicente Antonio , Rodriguez-Fortea Antonio , Poblet Josep M. 
Published: February 2020

We have observed new mechanistic insight into the formation of metallic nitride clusterfullerenes from doped graphite by use of laser-based plasma synthesis techniques, analyzed by ultrahigh resolution 9.4 tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. These online chemical sampling techniques provide a route to investigate underexplored nanocarbon reactions that take place under the harsh conditions of metallofullerene synthesis, and are expected to be applicable to macroscopic production methods. Here, we report efforts to form various clusterfullerenes by laser vaporization and extend these techniques as new avenues for investigation of exohedral functionalization (e.g., fluorination of Sc3N@C80) and heteroatom-doping of endohedral fullerenes.
This work was supported by NSF Division of Materials Research through DMR-11-57490 and the State of Florida.
(Invited) Hierarchical Nanostructures in Multi-Functional Electrocatalysts for the Artificial Leaf
Authors: Valenti Giovanni , Marcaccio Massimo , Rapino Stefania , Iurlo Matteo , Prato Maurizio , Fornasiero Paolo , Paolucci Francesco 
Published: February 2020

Nanomaterials are nowadays at the forefront of materials science research. The design and realization of hierarchical nanoarchitectures, in which selected components are arranged to leverage their expected mechanistic functions are obtaining a wide range of applications, from the aerospace industry to bio-medicine, and as benchmarks for many catalytic reactions.
Carbon-based nanomaterials have been the main actors of nanotechnology since their very first discovery, and their unique morphological/electronic properties are particularly suited to be used in electrocatalytic applications. CNTs and graphene are indeed ideal supports in catalysis as they have an optimal electronic conductivity and provide percolation routes for charge transfer reactions to occur. The integration of nanocarbons into hierarchical materials is an effective strategy to further boost the potentiality of nanostructured catalysts. The generation of multiple interfaces in such hierarchical assemblies is responsible for their exceptional activity, whose origin is however only rarely understood.
We will show that, once embedded within nanoarchitectures made of multi-wall carbon nanotubes or graphene and metal oxide shells, the catalytic properties of nanoclusters (1,2,5) and metal nanoparticles (3,4) can be dramatically enhanced according to mechanisms which likely involve the concerted and synergic participation of all component building blocks in the electrocatalytic steps.
References
(1) F.M. Toma et al., Nature Chemistry 2010, 2, 826
(2) M. Quintana et al. ACS Nano 2013, 7, 811–817
(3) R. Mazzaro et al. ChemistryOpen 2015, 4, 268 – 273
(4) G. Valenti et al. Nature Communications 2016, 7 DOI: 10.1038/ncomms13549
(5) A.B. Marco et al. Angew. Chem. Int. Ed. 2017, 56, 6946-6951
(Invited) Fullerene-Based Single Molecule Magnets: Bulk and Surface Magnetism
Authors: Popov Alexey A. , Krylov Denis , Chen Chia-Hsiang , Liu Fupin , Avdoshenko Stanislav , Brandenburg Ariane 
Published: February 2020

Encapsulation of lanthanides ions inside a carbon cage gives a variety of structures with very different magnetic properties, including single molecule magnetism (SMM). When other non-metal ions (N, S, O) are encapsulated as well, short distance between metal ions and negatively-charged non-metal ions creates large single-ion magnetic anisotropy of encapsulated lanthanides. In such clusterfullerene SMMs, very large barriers of the relaxation of magnetization can be achieved.[1] Encapsulation of only two metal atoms gives a possibility to create unique 3-center spin systems comprising large localized magnetic moments of lanthanide ions and an unpaired semi-delocalized spin on the metal-metal bonding orbital. In such a system, giant exchange interactions emerge and couple magnetic moments of individual spins into a giant superspin structure featuring unusually high blocking temperatures of magnetization.[2] Importantly, slow relaxation of magnetziatin is preserved even when fullerene-SMMs are deposited onto metal substrates, which usually has a dramatic deteriorating effect on SMMs. This contribution will present an overview of the recent developments in the magnetism of EMFs in bulk samples as well as in submonolayers deposited on metallic substartes..

References

[1] D.S. Krylov, F. Liu, S.M. Avdoshenko, L. Spree, B. Weise, A. Waske, A.U.B. Wolter, B. Büchner, A.A. Popov, Record-high thermal barrier of the relaxation of magnetization in the nitride clusterfullerene Dy2ScN@C80-Ih
, Chem. Commun., 53 (2017) 7901-7904.
[2] F. Liu, D.S. Krylov, L. Spree, S.M. Avdoshenko, N.A. Samoylova, M. Rosenkranz, A. Kostanyan, T. Greber, A.U.B. Wolter, B. Büchner, A.A. Popov, Single molecule magnet with an unpaired electron trapped between two lanthanide ions inside a fullerene, Nat. Commun., 8 (2017) 16098.
(Invited) Synthesis and Stabilization of the Unstable Dimetallofullerenes
Authors: Liu Fupin , Spree Lukas , Popov Alexey A. 
Published: February 2020

The metal-metal (M-M) bonding in dimetallofullerenes presents the peculiar electronic structures as well as the chemical and physical properties.[1-2] For Y and medium-size lanthanides (Gd, Tb, Dy), computations by Shinohara et al. showed that M2@C80 has one unpaired electron occupying the M–M bonding molecular orbitals, and the other electron is delocalized over the carbon cage (Figure 1a).[3] Such molecules are unstable radicals. Recently, we have succeeded in the capture of the elusive M2@C80 (M=Y, Dy) as benzyl derivatives (Figure 1b). The structure was unambiguously determined (Figure 1c, d).[4] In this contribution, the synthesis, separation, and structural characterizations of the elusive M2@C80 will be presented and discussed.
[1] A. A. Popov, S. Yang, L. Dunsch, Chem.
Rev.
2013, 113, 5989-6113.
[2] A. A. Popov, S. M. Avdoshenko, A. M. Pendas, L. Dunsch, Chem. Commun.
2012, 48, 8031-8050.
[3] Z. Wang, R. Kitaura, H. Shinohara, J. Phys. Chem. C
2014, 118, 13953-13958.
[4] F. Liu, D. S. Krylov, L. Spree, S. M. Avdoshenko, N. A. Samoylova, M. Rosenkranz, A. Kostanyan, T. Greber, A. U. B. Wolter, B. Büchner, A. A. Popov, Nat. Commun.
2017, 8, 16098.

Figure 1
(Invited) Fullerene Nanostructures: Preparation and Application
Authors: Zheng Shushu , Lu Xing 
Published: February 2020

During the past two decades, the self-assembly of spherical fullerene molecules has attracted intensive attention for their definite structures, high electronic affinity and three-dimensional (3D) electron transporting property. We report herein the systematical investigation of the self-assembly behavior of C60 molecules to form various polyhedron microstructures and well-aligned arrays together with their extraordinary optical properties.[
1
] Furthermore, a solution-processible co-assembly strategy taking advantage of charge-transfer interaction is developed to prepare C70/porphyrin supramolecular architectures, which possess excellent electrical conductivity and high thermal resistance, and charge separation characteristics.[
2,3
] More practically, porous carbon materials with abundant functional moieties are readily obtained by KOH activation of C70 microtubes, which exhibit excellent supercapacitor performances.[
4
]

References

[1] S. Zheng, et al., Carbon 201
8, DOI:10.1016/j.carbon.2017.10.012.
[2] S. Zheng, et al., Nano Res. 201
8, DOI:10.1007/s12274-017-1809-7.
[3] B. Wang, S. Zheng, et al., J. Am. Chem. Soc.
2017, 139, 10578.
[5] S. Zheng, H. Ju, X. Lu, Adv. Ener. Mater.
2015, 1500871.
The Catalytic Performance of Transition Metal Nitrides on Nitrogen Electroreduction and Hydrogen Evolution Reaction
Authors: Abghoui Younes , Skúlason Egill 
Published: February 2020

Renewable electrocatalytic synthesis of ammonia by nitrogen reduction reaction (NRR) at room temperature and ambient pressure has attracted numerous attentions in order to find a promising alternative to the centralized, energy-intensive, and CO2 emitting Haber-Bosch process. Despite all the efforts that have been made in this regard, NRR has yet been plagued with low faradaic efficiencies (FE) and reaction rates under ambient conditions with hydrogen evolution reaction (HER) considered as an important competitive side reaction. Here with the use of density functional theory, we have investigated a wide range of transition metal nitride (TMN) surfaces for possibility of catalyzing the NRR at ambient conditions1–6. We explored the thermochemistry of the cathode reaction so as to construct the free energy profile and to predict the required onset potential for activation of nitrogen to ammonia. Some of these materials were found not suitable for catalyzing ammonia formation mainly due to either poisoning or decomposition in electrochemical environment. However, some of earlier TMNs are predicted to catalyze ammonia formation at small onset potentials (-0.5 to -0.75 V) with considerable selectivity, while some other favoring the HER. When comparing the activity and the onset potentials predicted on these TMNs, it is seen that the Mars van Krevelen mechanism should be more favourable mechanism for NRR compared to the conventional associative and dissociative mechanisms. We recently tested few of the DFT predicted TMNs in experiments, and preliminary results indicate proof of concept and interesting performance of these materials under operating conditions.
Reference:
(1) Abghoui, Y.; Garden, A. L.; Hlynsson, V. F.; Björgvinsdóttir, S.; Ólafsdóttir, H.; Skúlason, E. Enabling Electrochemical Reduction of Nitrogen to Ammonia at Ambient Conditions through Rational Catalyst Design. Phys. Chem. Chem. Phys.
2015, 17 (7), 4909–4918.
(2) Abghoui, Y.; Garden, A. L.; Howalt, J. G.; Vegge, T.; Skúlason, E. Electroreduction of N2 to Ammonia at Ambient Conditions on Mononitrides of Zr, Nb, Cr, and V: A DFT Guide for Experiments. ACS Catal.
2016, 6 (2), 635–646.
(3) Abghoui, Y.; Skúlason, E. Electrochemical Synthesis of Ammonia via Mars-van Krevelen Mechanism on the (111) Facets of Group III–VII Transition Metal Mononitrides. Catal. Today
2017, 286, 78-84.
(4) Abghoui, Y.; Skúlason, E. Onset Potentials for Different Reaction Mechanisms of Nitrogen Activation to Ammonia on Transition Metal Nitride Electro-Catalysts. Catal. Today
2017, 286, 69–77.
(5) Abghoui, Y.; Skulason, E. Computational Predictions of Catalytic Activity of Zincblende (110) Surfaces of Metal Nitrides for Electrochemical Ammonia Synthesis. J. Phys. Chem. C
2017, 121 (11), 6141–6151.
(6) Abghoui, Y.; Skúlason, E. Hydrogen Evolution Reaction Catalyzed by Transition-Metal Nitrides. J. Phys. Chem. C
2017, 121 (43), 24036–24045.
Performance Analysis of a 5 Kw/30 Kwh Residential Vanadium Redox Flow Battery System in Denmark
Authors: Pérez Martínez Luis Carlos , Hansen Mads Weiss , Madsen Morten Brun , Bentien Anders 
Published: February 2020

The first residential vanadium redox flow battery system in Scandinavia was installed in Gladsaxe by Aarhus University and VisBlue Aps with support from the Energy Technology Development and Demonstration Program (EUDP) of Denmark. The flow battery has a nominal power output and capacity of 5 kW and 30 kWh respectively and is coupled to a 50 kW peak photovoltaic array. This solar plus storage system is integrated in a ten apartments building that already complies with the Danish Nearly Zero-Energy Building (NZEB 2020) energy performance requirements.
In this work, the performance of the vanadium redox flow battery system is reported for two periods, the first between February-December 2017 and the second between February-August 2018. Performance for different periods is analyzed based on the energy balance provided by the battery inverter and the data acquired from the flow battery. The energy balance is also used to map the consumer behavior in order to develop: 1) seasonal flow battery control strategies and 2) battery power and capacity optimal sizing methods. Since the flow battery operated intermittently during 2017 before final commissioning in February 2018, the photovoltaic array was coupled to a 7.4 kW lead-acid battery pack during specific periods. An overview of the lad-acid battery performance during these periods is also reported.
Finally, several technical challenges including coupling the vanadium redox flow battery with the battery inverter, stack leaks and remote monitoring of critical operating parameters are briefly discussed.
Characterizing the Decay of Redox Flow Battery Materials Utilizing a Microelectrode
Authors: Kowalski Jeffrey A , Brushett Fikile R. 
Published: February 2020

Redox flow batteries (RFBs) are a promising electrochemical technology for energy-intensive grid storage, but further cost reductions are needed for widespread adoption spurring research efforts into new redox chemistries and reactor designs1. Notably the recent emergence of redox active organic molecules offers intriguing new pathways to low cost energy storage through tunable molecular structure and inexpensive synthesis routes. While the rapid and continued advancement of these redox couples is exciting, iterative design-test-improve cycles are slowed as molecules become increasingly robust and failure modes become more subtle. Thus, there is a growing need for more advanced diagnostic techniques to evaluate materials performance, particularly stability2,3.
At present, common methods for characterizing the decay of RFB materials include extensive cycling in an electrochemical cell4 to correlate capacity fade to overall species decay or monitoring decay of a single reporter constituent (e.g. oxidized species) via different spectroscopy techniques (e.g. NMR3, EPR2, or UV-Vis5). However, these methods are challenged by, in the case of cell cycling, disambiguation of the sources of capacity fade, and, in the case of spectroscopies, issues operating under RFB relevant conditions (e.g. high concentrations of active species and supporting salt). Here, I will present a new technique to quantitatively probe active species stability in RFB-type electrolytes using a microelectrode. The talk will include discussion of underlying theory, systematic evaluation of sources of error, method validation using model compounds, and, finally, demonstration with several new redox couples.
References

M. L. Perry and A. Z. Weber, J. Electrochem. Soc., 163, A5064–A5067 (2016).

J. Huang et al., Sci. Rep., 6, 32102 (2016).

C. S. Sevov et al., J. Am. Chem. Soc., 139, 2924–2927 (2017).

J. Huang et al., J. Mater. Chem. A, 3, 14971–14976 (2015).

J. D. Milshtein et al., Energy Environ. Sci., 9, 3531–3543 (2016).
Improved Cycling Performance of Intermetallic Anode By Minimized SEI Layer Formation
Authors: Kuwata Hiroko , Matsui Masaki , Sonoki Hidetoshi , Manabe Yusuke , Imanishi Nobuyuki , Mizuhata Minoru 
Published: February 2020

Alloy anodes including intermetallic anode, such as Si, Sn, Sb or Al, have been widely studied to replace the standard graphite-based anode, because these anode active materials theoretically have much higher specific capacity than the graphite anodes. The biggest challenge of the alloy anode is its cycleability. Huge volume expansion/shrinkage during the lithiation/delithiation process leads the pulverization of the active material particles resulting in loss of the electric contact among active in the electrode.　Since the volume expansion/shrinkage also initiates formation/dissipation of electrode/electrolyte interphase, the SEI layer is supposed to have physical flexibility. However, the required physical properties of the SEI layer is not understood yet. We think the analogy of Mg-based system is useful, because the organohaloaluminate-based electrolyte solution of the Mg-based system does not form the typical SEI layer.
In the present study, electrochemical properties of bismuth composite electrode are investigated in magnesium and lithium system. The bismuth composite electrode shows good cycleability in a magnesium half-cell with an organohaloaluminate electrolyte solution, while sever capacity decay is observed in a lithium system with a conventional carbonate-based electrolyte solution. In the carbonate-based electrolyte solution, the bismuth composite electrode shows low coulombic efficiency of < 90% due to the formation of solid electrolyte interphase (SEI) layer, while the high coulombic efficiency is maintained in the magnesium system. The comparison of the two system suggests that the formation of the SEI layer accelerates the capacity fading. Another lithium-based electrolyte solution: 2M LiBH4 in THF is proposed as a minimized SEI formation electrolyte solution. The LiBH4-based electrolyte solution shows excellent cycleability with high coulombic efficiency. A spectroscopic study using in situ FTIR proved that the LiBH4-based electrolyte solution does not form the typical thick SEI layer.
Effects of a-Site Composition of Ru-Based Pyrochlore-Type Oxide on Catalytic Activity for Oxygen Reactions
Authors: Iketani Chinami , Kawaguchi Kenji , Morimitsu Masatsugu 
Published: February 2020

A metal hydride (MH)/air secondary battery uses oxygen in air as the active mass of the positive electrode. The positive electrode’s reactions are oxygen reduction and evolution during discharge and charge, and the polarization of the positive electrode significantly depends on the bi-functional oxygen catalyst. In our previous work [1], one of pyrochlore-type oxides (general formula A2B2O7), Bi2Ru2O7-z, showed a good performance on bi-functionality for charge and discharge, while the overpotential was still high for the oxygen reactions. On the other hand, pyrochlore-type oxides are known to be able to substitute various elements in A and/or B site as A2-xA’xB2-yB’yO7-z. In this paper, we tried to prepare this type of catalyst by partly substituting Bi with boron group elements, A’, i.e., Bi1-xA’xRu2O7-z, and investigated the polarization behaviors for oxygen reduction and evolution in KOH solutions using rotating disk electrode (RDE).
The oxide catalysts were prepared by co-precipitation method, in which the calcination of the precipitates obtained by adding excess NaOH solutions into the metal salt solution containing Bi(III), A’(III) (A’ = Al, In, Ga or Tl) and Ru(III). The obtained oxides were characterized by XRD, SEM, and EDX. Electrochemical measurements were carried out using a three-electrode cell, of which the working electrode was RDE and the electrolyte was 0.1 mol/L KOH solutions. The substrate of RDE was a titanium disk and the oxide particles prepared were dropped and dried on the titanium surface. The anodic polarization measurement by linear sweep voltammetry was performed, and the cathodic polarization was also examined by linear sweep voltammetry in the solution under N2 or O2 bubbling. The oxygen reduction current was obtained by subtracting the measured current under N2 bubbling from that under O2 bubbling. The specific activity of the oxide catalyst was evaluated by the currents normalized with the amount of the loaded catalyst, i
w, or the double layer charge, i
c.
The results by XRD for Bi0.9A’0.1Ru2O7-z (A’ = Al, In, Ga or Tl) and Bi2Ru2O7-z revealed that these oxides contained no by-product. Oxygen evolution showed no significant difference in catalytic activity for the oxides, while Bi2Ru2O7-z was superior in catalytic activity than Bi0.9A’0.1Ru2O7-z, implying that the change of ionic radius of A-site can affect the overpotential for oxygen reduction. In this paper, more results for the effects of the composition of A-site on the catalytic activity for oxygen reactions will be presented.

This work was supported by “Advanced Low Carbon Technology Research and Development Program (ALCA)” of Japan Science and Technology Agency (JST).

Reference
[1] T. Hirai, M. Morimitsu, PRiME 2016, Abs#0064, Hawaii (2016).
Break-in Phenomena in Commercial Alkaline & Li-Ion Batteries through Acoustic and Impedance Measurements
Authors: Hodson Thomas , Knehr Kevin William , Steingart Daniel A 
Published: February 2020

Alkaline batteries are a mainstay of the primary energy storage market, with LR6 (AA) batteries selling in the billions of cells per year. In addition, Lithium-Ion Batteries (LiBs) have become ubiquitous in modern technologies, such as in the burgeoning electric vehicle and consumer electronics markets. In both cases, the commercial cells undergo a “break-in” period after initial cycling period. In the case of alkaline cells, it has been noted that impedance changes drastically after initial discharge of a pristine cell [1]. After manufacturing the LiB, a period of break-in occurs wherein the battery experiences rapid changes in properties, such as capacity and stress [2], before leveling off to a stable value. Most research in these commercial cells analyze the full cycle life of the battery and have little regard for the initial break-in period. However, understanding and controlling break-in conditions could determine future performance of the cell. In this study, we use electrochemical acoustic and impedance spectroscopy measurements to analyze break-in of commercial AA and LiBs. We further analyze how break-in conditions, such as varying the rate of current, affect the overall performance of the battery.
[1] Hsieh, A.G. et al. “Electrochemical-acoustic time of flight: in operando correlation of physical dynamics with battery charge and health.” Energy Environ. Sci. (2015) 8, 1569-1577.
[2] Liu, Xinyi M., and Craig B. Arnold. "Effects of Cycling Ranges on Stress and Capacity Fade in Lithium-Ion Pouch Cells." Journal of The Electrochemical Society 163.13 (2016): A2501-A2507.