bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soft Probe Scanning Electrochemical Microscopy with Spider Array for Visualizing Biomarkers and Redox Active Proteins in Animal Tissues
Authors: Lin Tzu-En , Lu Yu-Jen , Sun Chia-Liang , Chen Jyh-Ping , Lesch Andreas , Girault Hubert H 
Published: February 2020

Biopsy is a diagnostic technique for tissue sampling in which a small piece of tissue is taken out from the patient and then sectioned into thin layers. The visualization of specific biomarkers, such as proteins and enzymes, inside the tissue section enables the identification of diseases, especially cancer, and is usually revealed by histochemistry combined with optical detection methods. However, optical methods can often be interfered by the presence of color pigments or auto-fluorescence in the sample.
Locally resolved electrochemical methods, such as scanning electrochemical microscopy (SECM), can detect in an electrolyte solution redox active species whose presence and concentration depend on a direct or enzymatically catalysed reaction at certain biomarkers. Specificity can be achieved by applying immunoassays or other labels, such as functionalized carbonaceous materials.
Standard SECM probes, usually made of metal or carbon micro-disks embedded in hard insulation materials, are of micrometer size and typically used in constant height mode to map the local biomarker concentration as well as distribution. However, tissues are mechanically very sensitive and of impacting topology. Especially topography is difficult to discriminate from the reactivity signal. We developed soft SECM spider probe arrays that brush in a gentle contact mode over tissues and thus enable constant distance mode imaging without inducing damages to the sample. The spider probe contains eight completely individual, parallel microelectrodes to scan square centimeter sized areas on reasonable time scales avoiding sample aging and electrode fouling. We present the successful SECM imaging of certain biomarkers, such as S100 protein and tyrosinase, in thin tumor tissues as well as thick tumor blocks. In addition, we demonstrate the use of the spider array for imaging redox active markers of a complete mouse heart section. This strategy could provide a better understanding of the interaction between redox mediators and redox active centers in animal organs.

References

[1] T.-E. Lin, A. Bondarenko, A. Lesch, H. Pick, F. Cortés‐Salazar, H. H. Girault, Angew. Chem. Int. Ed. 2016, 55, 3813–3816.
[2] A. Lesch, B. Vaske, F. Meiners, D. Momotenko, F. Cortés-Salazar, H. H. Girault, G. Wittstock, Angew. Chem. Int. Ed. 2012, 51, 10413–10416.
[3] T.-E. Lin, A. Lesch, C.-L. Li, H. H. Girault, Mapping the antioxidant activity of apple peels with soft probe scanning electrochemical microscopy, submitted

[4] T.-E. Lin, A. Lesch, H. H. Girault, Spider electrode array for visualizing biomarkers and redox active proteins in animal tissues by using soft probe scanning electrochemical microscopy, in preparation

Figure 1
Using a Semiconductor Detector with Tungsten Collimator for Removal of Tc/Pb Down-Scatter Interference in the Tl/Tc Dual-Isotope Spectrum
Authors: Passmore Gregory 
Published: February 2020

SPECT camera imaging of myocardium perfusion is dependent upon maintaining usable geometry between the sodium-iodide (NaI) detector and the view of the patient through the use of an attached lead (Pb) collimator. Both Tl-201 and Tc-99m radiopharmaceuticals can indicate the perfusion characteristics of the myocardium. Of the two, Tl-201 has the capability to differentiate between viable or scarred myocardium. Currently SPECT myocardial imaging protocols require two scans, a resting scan and a post-stress scan. Simultaneous imaging of Tl-201 rest and Tc-99m stress would have the benefits of eliminating potential errors caused by position misalignment between rest/stress scans, significantly reducing study time. In addition, simultaneous Tl-201/Tc-99m would provide optimal perfusion imaging and tissue viability signaling. This would further enhance the diagnostic ability of the modality, especially for those patients contraindicated for other functional imaging such as PET.
However, the standard Pb collimator interacts with the Tc-99m 140 keV photon to create Compton down-scatter components and k-shell x-rays which interfere with imaging the ~70-80 keV Tl-201 photons. This down-scatter reduces image resolution with the resolution poor NaI detector, and obscures Tl-201 defects, falsely indicating viable myocardium. Replacing the Pb collimator with one of differing density and lower energy K-shell x-ray cross-section would potentially reduce the Tc-99m down-scatter photons in the Tl-201 photopeak range by shifting the k-shell x-ray out of the Tl-201 photopeak. Using a semiconductor detector with superior resolution characteristics should allow isolation of both Tl-201 and Tc-99m photopeaks once the scatter components have been eliminated. The aim of the project was to test the ability of a semiconductor detection system with a tungsten (W) collimator in reducing the detrimental effects of Pb generated down-scatter during simultaneous dual-isotope 201Tl/99mTc imaging. Outcomes indicate a significant reduction in down-scatter and increased resolution using semiconductor detection system with W attenuators compared to NaI detection systems with Pb attenuators.
Scalable and Self-Aligned Growth of Two-Dimensional Transition Metal Dichalcogenides Lateral Heterojunctions for Optoelectronic Applications
Authors: Li Ming-Yang , Pu Jiang , Huang Jing-Kai , Miyauchi Yuhei , Matsuda Kazunari , Takenobu Taishi , Li Lain-Jong 
Published: February 2020

Recent development in atomically thin layered materials has provided a new possibility for studying two-dimensional (2D) physics. Among them, the monolayer transition metal dichalcogenides (TMDs) with direct bandgaps in the near-infrared to the visible region and with unique electrical and mechanical properties have attracted great research interests and have shown the application potential in optoelectronics. Furthermore, the TMDs heterojunction not only can form the p-n junction as the basic building block for logic circuits, also can provide a new route for band engineering which is of scientific and technology important for exploring next generation electronics. However, the difficulty on precise spatial and geometry control during synthesis or preparation is still an obstacle for 2D materials to integrate into real circuit applications.
Herein, we demonstrate a simple spatially controlled process for synthesizing self-aligned monolayer lateral TMDs heterojunctions array in centimeter scale. The selective growth from metal pad can help on in-situ location and geometry control for forming the heterojunction devices without patterning process. Meanwhile, this etching-free growth method provides a clean and high quality lateral junction. Our WSe2-MoS2 p-n junction exhibits clear current rectification effect and electroluminescence (EL) from the interface under forward bias > 3 V. Detailed EL mechanism shall be discussed. Our self-aligned growth can be easy applied in large scale device fabrication or integrate into circuit design for achieving optoelectronic applications, and also provide a better platform for fundamental studies.
In Situ Raman Spectroscopic Studies of Dioxygen Reduction in Ionic Liquid Based Electrolytes for Non-Aqueous Alkali Metal-O2 Batteries
Authors: Radjenovic Petar Martin , Hardwick Laurence J 
Published: February 2020

Superoxide (O2
-) is the key discharge intermediary driving many non-aqueous metal-oxygen battery cathode chemistries1–4. Fundamental investigations of the interphase at a roughened Au electrode in a variety of ionic liquid and solvent blended electrolytes have been performed to study electrolyte effects on the chemical nature of O2
- using in situ surface enhanced Raman spectroscopy (SERS). The observed (1095-1165cm-1) and (460-490cm-1) bond vibrations for O2
- at the electrode surface can vary greatly depending on the immediate coordinating environment5–7. Electrolytes that interact weakly with O2
- produce more radical oxide species that may be more likely to undergo parasitic side reactions and degrade alternatively, if stable, O2
- can diffuse away from the surface into the bulk electrolyte enabling a solution reaction pathway that has been linked with higher discharge capacities. Analysis of Raman peak positions, intensities and shifts in oxide spectral bands in different electrolytes and potentials allows for key information on O2
- radical character and its coordination environment to be elucidated. Overall four main parameters were shown to affect the radical character of O2
- at the interface in ionic liquid based electrolytes; (1) surface potential, (2) electrolyte cation, (3) electrolyte anion and (4) solvent electron acceptor/ donor numbers.
Ionic liquids have gained significant attention due to a number of innate physical and electrochemical properties. The significantly large combinations of ions provide the opportunity for electrolytes to be tailored towards specific application, however a clear electrolyte tailoring methodology is remains under developed. Our study provides important information in the oxygen reduction reaction mechanism that can aid in the ionic liquid selection and tailoring process.

References

1. Lu, J. et al.
Nature
529,1–7 (2016).
2. Johnson, L. et al.,
Nat. Chem.
6,1091–1099 (2014).
3. Hartmann, P. et al.,
Nat. Mater.
12,228–32 (2013).
4. Ren, X. & Wu, Y., J. Am. Chem. Soc.
135,2923–2926 (2013).
5. Galloway, T. A. & Hardwick, L. J., J. Phys. Chem. Lett.
7,2119–2124 (2016).
6. Aldous, I. M. & Hardwick, L. J., J. Phys. Chem. Lett.
5,3924–3930 (2014).
7. Aldous, I. M. & Hardwick, L. J., Angew. Chemie Int. Ed.
55, 8254–8257 (2016).

Figure 1
Influence of Electrolyte Additives and Formation Step Protocol on the Cycling Performance of Half and Full Li-Ion Cells
Authors: Sharova Varvara , Moretti Arianna , Diemant Thomas , Varzi Alberto , De Meatza Iratxe , Haon Cédric , Behm Rolf Jürgen , Passerini Stefano 
Published: February 2020

One of the key factors, which enables stable performance, cycle life and safety of lithium-ion batteries is the formation of the solid electrolyte interphase (SEI)1. SEI is formed on the surface of the graphite during the first and few initial cycles due to the reduction of the electrolyte components. The formation of this passive layer consumes Li ions, thus leading to the irreversible capacity loss. The control of the SEI formation and growth is complicated as it depends on a number of factors, such as type of graphite, electrolyte composition, cycling conditions and temperature2.
Organic electrolyte composition greatly influences the formation of the passive layer. State-of-the-art electrolytes are usually composed of a combination of cyclic (EC) and linear (DMC, EMC or DEC) carbonates and lithium salt (LiPF6). To provide an SEI with well-balanced physical-chemical characteristics additives are included in the electrolyte formulation. These additives usually decompose prior to the electrolyte main components during the first charge leading to the formation of more compact, stable and ionically conductive passive layer3.
The cell formation protocol also influences the properties of the SEI layer. It has been shown that high current density leads to the formation of porous SEI with high ionic and electronic conductivities, whereas low current density contributes to the formation of denser SEI with decreased electronic and increased ionic conductivities4.
Herein we investigate the influence of the imide-based salts (e.g. LiTFSI, LiFSI and LiFTFSI) as additives on the cyclability of Li-ion cells, comprising graphite and LiFePO4 electrodes with practical loading of ~2.5 mAh cm-2. The electrolytes are investigated focusing on their ionic conductivity and thermal stability. Furthermore, using half- and full-cells, the impact of different formation protocols on the capacity retention and cycling efficiency is evaluated. The SEI formed in different conditions is characterized by electrochemical impedance spectroscopy (EIS) and ex-situ x-ray photoelectron spectroscopy (XPS).

Acknowledgement

The authors kindly acknowledge the financial support from the EU under the H2020 project grant agreement no. 653373 (SPICY – Silicon and polyanionic chemistries and architectures of Li-ion cell for high energy battery).

References

1. Peled, E., J. Electrochem. Soc. 126 (12) 1979
2. Verma, P., et al., Electrochim. Acta 55 (22) 2010
3. Kalhoff, J., et al., ChemSusChem 8 (13) 2015
4. An, S. J., et al., Carbon 105 2016
Compliant Yet Brittle Mechanical Behavior of Li2s-P2S5 Li-Ion Conducting Solid Electrolyte
Authors: McGrogan Frank P , Swamy Tushar , Bishop Sean R. , Eggleton Erica , Porz Lukas , Chen Xinwei , Chiang Yet-Ming , Van Vliet Krystyn J. 
Published: February 2020

Li-ion batteries that include all solid-state components show promise as an emerging energy storage technology, as the solid electrolyte can improve safety and enable longer cycle life than current batteries based on flammable and reactive liquid electrolytes. Mechanical compatibility and durability of the solid components during large intercalation-induced volume changes are key concerns. For example, deformation and fracture of the solid electrolyte during cycling is expected to slow Li-ion conduction and create pathways for dendritic growth of metallic Li that can short-circuit the device. Identification and evaluation of key mechanical parameters of solid electrolytes is critical to predicting designs mitigating mechanical degradation.
With Li conductivity in excess of 10-4 S/cm, 70/30 mol% Li2S-P2S5 (LPS) is among the most promising solid electrolytes to date. Here we fabricated LPS and verified its amorphous structure and high ionic conductivity by X-ray diffraction and electrochemical impedance spectroscopy, respectively. We evaluated mechanical properties including Young’s elastic modulus, hardness, and fracture toughness via instrumented indentation as 18.5 +/- 0.9 GPa, 1.9 +/- 0.2 GPa, and 0.23 +/- 0.04 MPa m1/2, respectively. These measurements were enabled by immersion of the sample in nonreactive fluids that stabilized composition of this moisture-sensitive compound.
We found Young’s modulus to be in agreement with prior published values derived with alternative measurement techniques, and report the first measurements of hardness and fracture toughness. While the stiffness and hardness of this solid electrolyte material were much lower than that of active materials within battery electrodes, the fracture toughness was also surprisingly low relative to typical glass and ceramic materials. Thus, the mechanical behavior of this candidate solid electrolyte is compliant (low resistance to reversible deformation) and brittle (low resistance to fracture). We will discuss the relationship between these observed mechanical properties and integration of these materials as solid electrolytes in all-solid-state batteries.
(Invited) Nano-Scaled Perovskites for Oxygen Evolution in Alkaline Environment
Authors: Schmidt Thomas J. 
Published: February 2020

Oxygen electrodes are playing a key role in electrochemical energy conversion devices such as fuel cells and water electrolyzers. In both acidic and alkaline environment, both the oxygen reduction and oxygen evolution reaction (ORR and OER), respectively, are limiting the overall energy/voltage efficiency due to its sluggish kinetics. [1, 2]
Whereas in acidic environment, mainly precious metal oxides are used to catalyze the OER (e.g., IrO2), the variety of possible catalysts in alkaline electrolyte is significantly increased and many metal oxide based systems can be employed. Generally the oxygen evolution mechanism is only partly understood independent of the electrolyte environment and material used. In order to help to understand the underlying mechanism for the OER and to support the experimental results, very often computational methods are used, mainly using density functional theory (DFT) calculations. Similar approaches are also used for gaining insights into catalyst stabilities under operational conditions.
In this talk, some of your recent findings on non-noble metal catalysts, mainly from the perovskite family will be presented. By employing operando X-ray absorption spectroscopy (both XANES and EXAFS), important insights could be gained with respect to the perovskite electronic structure and the local catalyst structure helping to better understand the underlying mechanism for the OER.

Acknowledgement:

This work is supported by the Swiss National Science Foundation, the Swiss Competence Center for Energy Research (SCCER) Heat & Electricity Storage, the Swiss Federal Office of Energy and the Competence Center Energy & Mobility Switzerland.
References

[1] A. Rabis, P. Rodriguez, T.J. Schmidt, ACS Catal., 2012, 2 (5), 864–890
[2] E. Fabbri, A. Habereder, K. Waltar, R. Kötz, T.J. Schmidt, Cat. Sci. Tech., 2014, 4, 3800-3821
(Invited) Integrated Metal Oxide Hybrid Perovskite Photoelectrode for Efficient Photoelectrochemical Water Splitting
Authors: Roy Subhasis , Botte Gerardine G 
Published: February 2020

In these present days where developing unconventional sources of energy is a major concern, sunlight-driven water splitting has attracted much attention due to sustainable hydrogen fuel production as a substitute of conventional energy. Although sunlight-driven water splitting is an eco-friendly and interminable energy source, extensive implementation is hindered by the expense of the essential photo anode.1-2

In this contribution, we demonstrate an efficient and low-cost water-splitting cell by combining a charge carrier metal oxide semiconductor - processed multidimensional perovskite thin films photoanodes. Effort has been made to prepare nanostructured morphologies of metal oxide as well as perovskite photoanodes that possesses optimized surface catalytic reactions; as well as high photocurrent by controlling the morphology of the structure.3-4This nanostructure material capable to overcome the shortcoming of the short hole diffusion length and enhancing photocurrent. The spectral absorbance of the materials have been also fine-tuned by controlling dimensionality of the structures as well as through doping. We optimized the necessary parameters for high performance photo electrochemical water splitting, by balancing photon absorption and charge carrier transport. A significant improvement in the state-of-the-art perovskite photo anodes through an enhancement in electron transport in films attained and these porous photoanodes films could be easily modified by metal doping for further enhanced photo electrochemical activity for solar water splitting.
This hybrid “modify perovskite nanostructures” composites is different from existing composites in that they (i) are produced using benign solvents and processing techniques, and (ii) possible to modify to introduce virtually any desired functionality tailored to the desired application. Our materials are much simpler to prepare and can easily be modified with virtually any desired functionality to optimize performance in different applications. Specific properties can also be dialled in by choosing the appropriate linking molecule (rigidity/flexibility, stimulus responsiveness, etc.). The flexibility of this approach leads to practically unlimited possibilities, while the technology is based on the most abundantly available in nature.
References

Y. Kuang, Q. Jia, H. Nishiyama,T. Yamada, A. Kudo, K. Domen, Advanced Energy Materials, 2016, 6, 1501645-51.

A. Kudo, K. Omori, H. Kato, Journal of the American Chemical Society
, 1999, 121 11459-67.

K. Sayama , A. Nomura , Z. Zou , R. Abe , Y. Abe , H. Arakawa , H. Arakawa , Chemical Communications,
2003 , 39 , 2908-2909.

K. Kim, P. Thiyagarajan, H.-J. Ahn, S.-I. Kim and J.-H. Jang, Nanoscale, 2013, 5, 6254–6260
Hierarchical NiCo2O4 Micro-/Nanostructures with Tunable Morphologies As Anode Materials for Li-Ion and Na-Ion Batteries
Authors: Chan Wai Leong Mickey , Fu Fang , Li Jiadong , Yao Yuze , Shao Minhua 
Published: February 2020

Binary metal oxide NiCo2O4 is a promising anode material for future Li-ion batteries (LIBs) and Na-ion batteries (SIBs) owing to its inherited characteristics of high theoretical capacity and low cost.1,2 In particular, NiCo2O4 possesses high electrical conductivity, reversible capacity and mechanical stability than single-component metal oxides NiO and Co3O4.
3,4 However, the large volume change and sluggish kinetics during the charge/discharge process result in a short cycling life and poor rate performance, which limits its practical application.5

The electrochemical performance of an active material highly depends on its structure (both primary and secondary structures).6 Therefore, tailored architecture design and surface engineering of NiCo2O4 are highly desirable to secure both the high transport kinetics and sustain the structure integrity for high rate and long life.
In this study, one-dimensional (1D) porous NiCo2O4 microrods and microspheres are successfully synthesized by a simple solvothermal method using different solvents followed by calcination. The solvothermal process and solvents employed in the synthesis play crucial role in determining the final morphologies of NiCo2O4. Compared with NiCo2O4 microspheres, the porous microrods exhibit much better Li- and Na-ion storage properties owing to the 1D geometry to facilitate fast ion transport and the porous structure to accommodate volume expansion of NiCo2O4 during ion insertion. The porous NiCo2O4 microrods display high initial charge capacity (1046.1 mAh g-1 at 100 mA g-1), long cycling stability (719 mAh g-1 after 600 cycles at 500 mA g-1), and rate capability for lithium-ion batteries. They also show better performance in sodium-ion batteries. This work may provide a facile way for fabricating novel structured metal oxide anode materials for batteries.
Figure 1. (Left) SEM images of the 1D porous NiCo2O4 microrods and microspheres for LIBs and SIBs respectively. (Right) Rate performances at various current densities of LIBs and SIBs.

References

Zheng, F. C.; Zhu, D. Q.; Chen, Q. W. ACS Applied Materials & Interfaces
2014, 6, (12), 9256-9264.

Lee, Y.; Kim, M. G.; Cho, J. Nano letters
2008, 8, (3), 957-961.

Li, B.; Feng, J.; Qian, Y.; Xiong, S. Journal of Materials Chemistry A
2015, 3, (19), 10336-10344.

Jadhav, H. S.; Kalubarme, R. S.; Park, C. N.; Kim, J.; Park, C. J. Nanoscale
2014, 6, (17), 10071-10076.

Chen, J.; Ru, Q.; Mo, Y.; Hu, S. RSC Advances
2015, 5, (90), 73783-73792.

Ye, J.; Liu, W.; Cai, J.; Chen, S.; Zhao, X.; Zhou, H.; Qi, L. Journal of the American Chemical Society
2010, 133, (4), 933-940.

Figure 1