bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dual Electrolyte Aluminum-Air Flow Battery Using Methanol Anolyte
Authors: Teabnamang Pemika , Kheawhom Soorathep 
Published: February 2020

Aluminum-air batteries have received considerable attention as a cost-effective energy storage system due to their high theoretical specific capacity of 2.98 Ah/g. However, corrosion of the aluminum anode in alkaline electrolyte limits their practical application. Herein, this issue was addressed by implementing dual electrolyte flow battery. The cell structure consists of aluminum anode | anolyte | anion exchange membrane | catholyte | air cathode.
The anolyte is 3M KOH in methanol containing different percentages of deionized water (0, 5, 10 and 20) wt. %. The catholyte is a gel polymer electrolyte based on Carbopol 940. The results showed that the increase of water content in the anolyte reduces the overpotential of the cell but increases hydrogen evolution (anode corrosion). At 10 mA/cm2 current density, the anolyte without water showed the highest specific capacity of 2,328 mAh/g, which is 78% aluminum utilization. The specific capacity significantly decreases as the water content in the anolyte increases due to the higer rate of the anode self-corrosion.
Freeze Tape Casting Derived Li7La3Zr2O12 Electrolyte Architecture with Oriented Ion Conduction Channels
Authors: Yi Eongyu , Shen Hao , Sofie Stephen , Chen Guoying , Doeff Marca 
Published: February 2020

The high interfacial impedance of garnet electrolyte based solid state batteries has been addressed recently by constructing 3D interfaces in which a random network of solid electrolyte extends to the anode/cathode layer to serve as anolyte/catholyte. Thicker active material layers can be achieved with minimal performance loss compared to deposition derived approaches in such configurations as well. The cell architecture can be further improved by forming directional solid electrolyte channels with low pore tortuosity approaching unity compared to randomly oriented pores, thus imparting higher ion mobility along the transport direction during charge/discharge. Freeze casting, magnetic alignment, and laser ablation are some of the methods that have been used in forming aligned ion conduction channels in lithium ion battery applications and have shown performance improvement over the randomly oriented counterpart.
In order to build 3D interfaces with vertically aligned solid electrolyte channels at practical sample thicknesses with potential for scaling, we introduce freeze tape-casting, a combination of tape-casting and freeze casting, to continuously produce green tapes of Li7La3Zr2O12 with vertically aligned pore channels. LLZO was selected as it is one of the most promising solid electrolytes and is stable with Li metal anodes. On sintering, LLZO scaffolds in which LLZO sheets are vertically aligned are obtained. In parallel, processing optimization has been made on producing sintered thin films of LLZO by tape-casting and sintering. We show that porous/dense bi-layers and porous/dense/porous tri-layers of LLZO are produced readily by stacking and sintering the tape-cast and freeze tape-cast LLZO green tapes. Pores are filled with active material and current collector components to complete the cell, and the porous layers of various thicknesses can be mixed and matched as desired per loading requirements. The thicknesses of the porous and dense layers could be reduced down to 100 and 30 µm, respectively. This novel solid electrolyte framework shows great potential to advance the field of solid state battery research. Furthermore, the approach can readily expand to other Li or Na conducting oxide electrolytes to take advantage of the unique architecture.
(Invited) Prato Addition to C70: A New Adduct and Water-Soluble Derivatives
Authors: Liosi Korinne , Yamakoshi Yoko 
Published: February 2020

Due to the higher absorption of light at longer wavelengths and increased lifetime of the triplet state, C70has been recognized as a better photosensitizer than C60for applications in photodynamic therapy (PDT). Similar to C60, the main obstacle to bioapplication of C70is its hydrophobicity, resulting in insolubility in water or water-miscible solvents and rendering functionalization with water-soluble anchors necessary. Additional complications in the functionalization of C70is lower symmetry of the molecule in comparison to C60. Even mono-addition reactions can provide several distinct derivatives of C70, which may exhibit a different range of the functions of the obtained derivatives.
In this study, we used a 1,3-dipolar cycloaddition reaction (Prato reaction) for the functionalization of C70. It is known that this reaction provides very stable pyrrolidine adducts of fullerenes in sufficient yields. We used a N-glycine derivative 1and formaldehyde in the Prato reaction; three obtained adducts (2A-C) were purified by HPLC (Figure) and their structures were elucidated by 1H and 13C NMR. While the addition sites of two major adducts 2Aand 2Bwere found to be ab-[6,6] and cc-[6,6] – similar to the previous reports – the structure of the third minor adduct 2Cwas determined as dd-[5,6]-2,in contrast to the previous studies. The deprotection of major adducts 2A-B under acidic conditions and subsequent conjugation with PEG-NH2derivatives successfully provided water-soluble C70-PEG conjugates.

Figure 1
(Invited) Self-Assemble of Supramolecular Polymers of Porphyrin-Bisfulleropyrazoline Tweezers
Authors: Caballero Ruben , Langa Fernando , de la Cruz Pilar 
Published: February 2020

Along the last years, the utilization of non-covalent interactions for the construction of supramolecular polymers has evolved as one of the most attention-grabbing fields in chemistry leading to new materials with exciting properties. Considering the different types of motifs, p-p interactions have been scarcely studied.
Here, we will present the regioselective synthesis of a fulleropyrazoline-bisadduct by tethered directed synthesis from bisnitrile imines, opening of the tether and preparation of a tweezer bis-(Zn-Porphyrin)fullerene. Interestingly, the formation of oligomers by p-p fullerene-porphyrin interaction up to 13 units has been detected by MALDI-TOF mass spectrometry.

Figure 1
(Invited) Synthesis of the Elusive 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, 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.[3] Such molecules are elusive radicals. Recently, we have succeeded in the capture of the elusive M2@C80 (M=Y, Gd, Tb, Dy, Ho, and Er) as benzyl derivatives.[4] In this contribution, the synthesis and structural characterizations of these M2@C80–CH2Ph will be 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.
(Invited) MXenes: From Fundamental Science to Emerging Applications
Authors: Kurra Narendra , Gogotsi Yury 
Published: February 2020

Two-dimensional (2D) nanomaterials have been attractive candidates for a plethora of applications since the successful isolation and demonstration of intriguing electronic properties of graphene in 2004 by the Manchester group. The ‘beyond graphene’ march led to the discovery of new types of 2D materials, expanding the flatland research. MXenes, a relatively new and large family of 2D transition metal carbides, nitrides, and carbonitrides, which were discovered at Drexel in 2011 and have become popular due to their diverse chemistries and unique physicochemical properties. These materials are produced by top-down wet chemical or electrochemical extraction of interleaved ‘A’ atomic layers from the layered ternary carbide precursors (MAX phases). The resulting MXenes with surface terminations (-O, -F, -OH) impart negative surface charges, key for stable MXene dispersions in water and organic solvents which enable solution processing. More than 30 different MXenes have been experimentally synthesized, with dozens of new MXenes and their properties predicted computationally. The compositional versatility, metallic conductivity, control of surface chemistry, ordered structures versus solid solutions, etc. make MXenes diverse and suitable for a wide spectrum of applications including but not limited to energy storage, photo- and electro-catalysis, water desalination, optoelectronics, electromagnetic interference shielding, antennas, and smart textiles.
The available 2D gallery spaces, redox chemistry at the transition metal oxide-like surface with metallic conductivity, enable MXenes as potential candidate materials for high rate capacitive energy storage applications. The ability of MXenes to spontaneously intercalate a variety of cations while promoting fast charge transfer rates, endorses them for hybrid metal-ion capacitors and battery applications. The electrocatalytic property of MXenes can be tuned based on type of transition metal, amount of defects and surface functionality. Furthermore, combination of slit-like pores with electronic conductivity, qualifies MXenes as capacitive deionization (CDI) electrodes for efficient and reversible removal of ionic species/organic molecules from brackish water. Unlike most of the 2D materials produced by bottom-up routes in small quantities, pilot scale synthesis of MXenes is a promising aspect for immediate future commercialization.
(Invited) Efficient Photodetection in 2D Materials and 2D/3D Heterostructures
Authors: Lemme Max Christian 
Published: February 2020

This talk will focus on efficient and broadband photodetectors made from heterostructures of two-dimensional materials and conventional semiconductors [1], [2]. Graphene/silicon photodiodes show particularly high response, when the graphene is partly separated from the silicon by an oxide [3]. This effect is utilized in a specific contact pattern scheme that includes both regions of graphene/silicon Schottky diodes and graphene/silicon oxide/silicon (MOS) structures to enable highly sensitive G/Si photodiodes [4]. With this design, we achieve an external quantum efficiency (EQE) of > 80% for wavelengths between 380 and 930 nm. The maximum EQE of 98% is observed at 850 nm, where the responsivity also peaks to 635 mA/W. This high value is attributed to the highly effective collection of charge carriers in the MOS parts of the diodes and outperforms conventional Si p-n photodiodes. Based on these results, we define the ‘true’ active area in G/Si photodiodes.
The transition metal dichalcogenide (TMD) molybdenum disulfide (MoS2) is an n-type semiconducting 2D material with a direct band gap of ~1.8 eV in single layer form, while bulk MoS2 has an additional indirect band gap of ~1.3 eV. MoS2/Si heterostructure diodes made with multilayer, CVD grown MoS2 yield a maximum spectral response of 8.6 mA/W [1]. Furthermore, MoS2-based photodiodes on flexible substrates will be discussed. Finally, recent results on the TMD platinum diselenide (PtSe2) will be presented. Made from thermally converted platinum at low temperatures [5], [6], PtSe2 is semimetallic and is an efficient absorber in the infrared range [7].
[1] C. Yim et al., “Heterojunction Hybrid Devices from Vapor Phase Grown MoS2,” Sci. Rep., vol. 4, Jun. 2014.
[2] S. Riazimehr et al., “Spectral sensitivity of graphene/silicon heterojunction photodetectors,” Solid-State Electron., vol. 115, Part B, pp. 207–212, Jan. 2016.
[3] S. Riazimehr et al., “High Photocurrent in Gated Graphene–Silicon Hybrid Photodiodes,” ACS Photonics, vol. 4, no. 6, pp. 1506–1514, Jun. 2017.
[4] S. Riazimehr et al., “High Responsivity and Quantum Efficiency of Graphene / Silicon Photodiodes Achieved by Interdigitating Schottky and Gated Regions,” ACS Photonics, 2018.
[5] C. Yim et al., “High-Performance Hybrid Electronic Devices from Layered PtSe2 Films Grown at Low Temperature,” ACS Nano, vol. 10, no. 10, pp. 9550–9558, Oct. 2016.
[6] C. Yim et al., “Electrical devices from top-down structured platinum diselenide films,” Npj 2D Mater. Appl., vol. 2, no. 1, p. 5, Feb. 2018.
[7] C. Yim et al., “Wide Spectral Photoresponse of Layered Platinum Diselenide-Based Photodiodes,” Nano Lett., vol. 18, no. 3, pp. 1794–1800, Mar. 2018.
(Invited) Controlling and Tailoring the Electronic Properties of Chemically Reactive 2D Materials
Authors: Hersam Mark C. 
Published: February 2020

Following the success of ambient-stable two-dimensional (2D) materials such as graphene and hexagonal boron nitride (hBN), new classes of chemically reactive layered solids are being explored since their unique electronic and optical properties hold significant promise for improved device performance [1]. For example, chemically reactive 2D semiconductors such as black phosphorus (BP) and indium selenide (InSe) have shown significantly enhanced field-effect mobilities under controlled conditions that minimize ambient degradation [2]. In addition, 2D boron (i.e., borophene) is an anisotropic metal with a diverse range of theoretically predicted phenomena including confined plasmons, charge density waves, and superconductivity [3], although its high chemical reactivity has limited experimental studies to inert ultrahigh vacuum conditions [4-6]. Therefore, to fully study and exploit the vast majority of 2D materials, methods for mitigating or exploiting their relatively high chemical reactivity are required [7]. This talk will thus explore recent efforts to control and tailor the electronic properties of chemically reactive 2D materials [8]. In particular, covalent organic functionalization of black phosphorus minimizes ambient degradation, provides charge transfer doping, and enhances field-effect transistor mobility and on/off ratio [9]. In contrast, noncovalent organic functionalization of borophene leads to the spontaneous formation of electronically abrupt lateral organic-borophene heterostructures [10]. Finally, atomic layer deposition (ALD) encapsulation schemes will be discussed that impart ambient stability to high-performance black phosphorus infrared optical emitters [11] and InSe photodetectors [12].
[1] A. J. Mannix, et al., Nature Reviews Chemistry, 1, 0014 (2017).
[2] D. Jariwala, et al., Nature Materials, 16, 170 (2017).
[3] A. J. Mannix, et al., Nature Nanotechnology, 13, 444 (2018).
[4] A. J. Mannix, et al., Science, 350, 1513 (2015).
[5] G. P. Campbell, et al., Nano Letters, 18, 2816 (2018).
[6] X. Liu, et al., Nature Materials, 17, 783 (2018).
[7] C. R. Ryder, et al., ACS Nano, 10, 3900 (2016).
[8] X. Liu, et al., Advanced Materials, 30, 1801586 (2018).
[9] C. R. Ryder, et al., Nature Chemistry, 8, 597 (2016).
[10] X. Liu, et al., Science Advances, 3, e1602356 (2017).
[11] C. Husko, et al., Nano Letters, 18, 6515 (2018).
[12] S. A. Wells, et al., Nano Letters, DOI: 10.1021/acs.nanolett.8b03689 (2018).
(Invited) Effect of Particle Size on Photocatalytic Reaction Kinetics Including Multielectron-Transfer Processes
Authors: Ohtani Bunsho , Takashima Mai 
Published: February 2020

Oxidation of water into molecular oxygen (O2 + 4H+ + 4e– → 2H2O) must be the largest-scale chemical reaction occurring on the earth as a part of photosynthesis by plants, and the corresponding backward half-cell reaction, reduction of oxygen into water (O2 + 4H+ + 4e– → 2H2O) might proceed in the same scale by the activity of plants and animals to get energy by combustion of chemicals keeping the concentration of oxygen on the earth. It is well known that the forward and backward reactions are counter oxidation and reduction reactions, respectively, of photocatalytic water splitting/carbon-dioxide fixation and photocatalytic decomposition of organic compounds by semiconductor particles.
Standard electrode potential (SEP) of this four electron-transfer redox (O2 + 4H+ + 4e– = 2H2O) is 1.23 V (versus SHE = standard hydrogen electrode potential (0 V) in definition). Almost all the papers reporting oxygen evolution use this SEP, while those of photocatalytic organics decomposition tend to use SEP for one-electron transfer, O2 + e– = O2•– (–0.28 V), for discussion. One of the possible reasons for such difference is that it is convenient to presume the production of superoxide anion radical which may produce "reactive oxygen species (ROS)" to decompose organic compounds. Anyway, it can be stated that those proposed number of transferred electrons seems speculative without any experimental evidence.
We have been studying light-intensity dependence (LID) of photocatalytic reaction rates using highly intense UV-LEDs with intensity maximally ca. 3 W cm-2. For oxygen evolution from aqueous titania suspensions in the presence of electron acceptors such as iodate (IO3
–) or iron(III) ions under deaerated conditions, small anatase (8 nm) and rutile (13 nm) particles show bimodal, at first second and then first order, LID in the lower and middle intensity range while large anatase and rutile particles show simple first-order LID in the whole intensity range. This is attributable to two-electron (positive hole) transfer process in the initial step. An interesting feature is that forth-order LID was observed with small anatase particles at high (2.5 W cm-2) intensity to suggest shift of the kinetics to four-electron transfer process [1]. For oxygen reduction, LID analyses for the rate of oxidative decomposition of acetic acid by a bismuth tungstate photocatalyst suggested that two-electron oxygen reduction predominantly proceeds [2]. On the basis of these results, "effective particle size" defined as size of particle (or particle aggregates) in which multiple electrons (positive holes) are accumulated to induce multielectron processes is proposed. This "effective particle size" may govern the effect of size on photocatalytic reaction rates.
[1] Takeuchi, S.; Takashima, M.; Takase, M.; Ohtani, B. Chem. Lett.
2018, 47, 373-376.
[2] Hori, H.; Takashima, M.; Takase, M.; Ohtani, B. Catal. Today
2018, 313, 218-223.
(Invited) Synthesis of Multimetallic Subnano Particles Using a Dendrimer Reactor
Authors: Yamamoto Kimihisa 
Published: February 2020

Dendrimers are highly branched organic macromolecules with successive layers or “generations” of branch units surrounding a central core. Organic inorganic hybrid versions have also been produced, by trapping metal ions or metal clusters within the voids of the dendrimers. Their unusual, tree-like topology endows these nanometer-sized macromolecules with a gradient in branch density from the interior to the exterior, which can be exploited to direct the transfer of charge and energy from the dendrimer periphery to its core.
We show that tinchloride, SnCl2 and FeCl3 complexes to the imines groups of a spherical polyphenylazomethine dendrimer in a stepwise fashion according to an electron gradient, with complexation in a more peripheral generation proceeding only after complexation in generations closer to the core has been completed. By attaching an electron-withdrawing group to the dendrimer core, we are able to change the complexation pattern, so that the core imines are complexed last. By further extending this strategy, it should be possible to control the number and location of metal ions incorporated into dendrimer structures, which might and uses as tailored catalysts, building blocks, or fine-controlled clusters for advanced materials.　The metal-assembly in a discrete molecule can be converted to a size-regulated metal particle with a size smaller than 1 nm as a molecular reactor. Due to the well-defined number of metal particles in the subnanometer size region, its property is much different from that of bulk or general metal nanoparticles.
Bis-Porphyrin Structural Motiff for Chirality and Molecular Sensing
Authors: Du Rui , Zhou Zhongqiang , Borovkov Victor 
Published: February 2020

Bis-porphyrin structures are widely used as model systems to mimic various natural processes and have numerous practical applications in the research and technoligical fields such as polymer and nano science, light harvesting and nonlinear optics, chemical sensors and catalysis, molecular and chiral recognition, various supramolecular and chiroptical devices, chirogenesis and absolute configuration determination.
Several years ago, we have discovered that a simple ethane-bridged bis-porphyrin structural motif (M = Zn, Mg, Cu, Co, 2H), can be effectively served for different application purposes owing to the specific molecular and supramolecular functionalities. In particular, the unique functional property of this bis-porphyrin host is based upon the structural semi-flexibility of covalent linkage between two porphyrin unitsresulting in the environmentally assisted syn-anti conformational switching and tweezer formation depending upon the guest structure, which can be effectively employed in different sensing areas, such as chirogenic probes, chiral recognitions, and chemical sensors .1-13

Further developments and prospects toward new chiral and achiral bis- and multi porphyrin systems on the basis of heterometallic bis- and multi-porphyrin structures will be discussed.

Borovkov, Symmetry
2014, 6, 256.

Borovkov, Symmetry
2010, 2, 184.

Borovkov, Y. Inoue, Eur. J. Org. Chem.
2009, 189.

A. Hembury, V. V. Borovkov, Y. Inoue, Chem. Rev.
2008, 108, 1.

V. Borovkov, Y. Inoue, Top. Curr. Chem.
2006, 265, 89.

V. Borovkov, G. A. Hembury, Y. Inoue, Acc. Chem. Res.
2004, 37, 449.

Giancane, V. Borovkov, Y. Inoue, L. Valli, J. Colloid Interface Sci.
2012, 385, 282.

Giancane, V. Borovkov, Y. Inoue, S. Conoci, L. Valli,Soft Matter
2013, 9, 2302.

Bettini, E. Maglie, R. Pagano, V. Borovkov, Y. Inoue, L. Valli, G. Giancane, Beilstein J. Nanotechnol.
2015, 6, 2154.

Colombelli, M.G. Manera, V. Borovkov, G. Giancane, L. Valli, R. Rella, Sensor Actuat. B-Chem.
2017, 246, 1039.

Buccolieri, D. Manno, A. Serra, A. Santino, M. Hasan, V. Borovkov, G. Giancane,Sensor Actuat. B-Chem.
2018, 257, 685.

Buccolieri, M. Hasan, S. Bettini, V. Bonfrate, L. Salvatore, A.Santino, V. Borovkov, G.,Giancane, Anal. Chem.
2018, 90, 6952.

Bettini, R. Pagano, V. Borovkov, G. Giancane , L. Valli, J. Colloid Interface Sci.
2019, 533, 762-770.