bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hierarchical Ru and RuO2 Foams with Superior Performance for Rechargeable Lithium Oxygen Battery Cathodes
Authors: Suk Jungdon , Kwak Kyoung Hwan , Kang Yongku 
Published: February 2020

Synthesis and structure design of cathode materials with superior catalytic activity is still major challenge for rechargeable lithium-oxygen batteries. Among many cathode materials, carbons are often used because they help achieve high discharge capacities and good ORR performance. However, most lithium-oxygen batteries containing carbon electrodes suffer from a low round-trip efficiency, low rate capability, a poor cycle life, and electrolyte instability. In this poster, we report a binder- and carbon-free, 3D porous Ru- and RuO2-foam cathode for lithium-oxygen batteries. The cathode was simply fabricated by three-step process; co-electrodeposition, electrochemical dealloying and heat treatment process. Both 3D porous Ru- and RuO2-foams have lots of cavity and pits which provide a large surface area for catalytic sites and buffer spaces for the volume stress by the formation/decomposition of Li2O2 during the cycling process. Moreover, cathodes made of Ru- and RuO2- foam can provide high catalytic activities, short ion diffusion length and channels for rapid transport of oxygen and electrolyte. The hierarchically dendritic cathodes without carbon and binder present low charge/discharge overpotential, remarkable cyclability, good oxygen efficient and reduced irreversible formation form electrolyte decomposition. We systematically investigated the reversibility and cyclability of a lithium-oxygen battery using the 3D porous Ru- and RuO2-foam cathode using scanning electron microscopy (SEM), X-ray diffraction (XRD), selected area electron diffraction (SAED), in-situ Differential Electrochemical Mass Spectrometry (DEMS) and FT-IR spectroscopy. The results using the 3D porous nanostructured electrodes in our study represent a promising approach for high-performance electrodes which are compatible with scaled-up manufacturing process for next-generation lithium- air batteries due to their simple and rapid fabrication process.
1. Fujun Li, Tao Zhang, Haoshen Zhou, Energy Environ. Sci. 6, 1125-1141 (2013) 2. Fujun Li, Dai-Ming Tang, Yong Chen, Dmitri Golberg, Hirokazu Kitaura, Tao Zhang, Atsuo Yamada, and Haoshen Zhou, Nano letter, 13, 4702-4707 (2013) 3. Fujun Li, Dai-Ming Tang, Zelang Jian, Dequan Liu, Dmitri Golberg, Atsuo Yamada, Haoshen Zhou, Adv. Mater., 26, 4659-4664 (2014) 4. Myung-Gi Jeong, Kai Zhuo, Serhiy Cherevko, Woo-Jae Kim, Chan-Hwa Chung, J. of Power Sources, 244, 806-811 (2013)
A Renewable Anthraquinone Derivative As Organic Anode Materials for Sodium-Ion Batteries
Authors: Wu Dabei , Huang Yunhui , Hu Xianluo 
Published: February 2020

Most renewable energy, like wind energy and solar energy, is dispersive and discontinuous because of energy distribution and geographic factors. Therefore, we need energy storage devices to collect and store them. Na-ion batteries are suitable for large-scale energy storage considering abundant natural resources.1 Here, we report a renewable anthraquinone derivative as organic anode materials for sodium-ion batteries. The alizarin is extracted from the roots of madder. Results show that the first discharge capacity is as high as ~700 mAh/g and the capacity keeps at ~150 mAh/g after continuous discharge/charge cycles, as shown in Figure 1. The different status of the fully and partially discharged/charged electrodes was investigated, and the related Li-cycling mechanism was also explored.
References:
1. Slater, M. D.; Kim, D.; Lee, E.; Johnson, C. S., Sodium-Ion Batteries. Advanced Functional Materials 2013, 23 (8), 947-958.

Figure 1
Spinel NiCo2O4-Deposited CNT Bucky Paper As a Cathode for Rechargeable Li-O2 Battery
Authors: Jung Kyu-Nam , Lee Jong-Won 
Published: February 2020

There has been a great interest in the development of rechargeable batteries with high energy storage capability due to an increasing demand for electric vehicles (EVs) with driving ranges comparable to those of gasoline-powered vehicles. Among various types of batteries under development, a Li–oxygen(O2) battery delivers the highest theoretical energy density, thus, it is considered a promising energy storage technology for EV applications [1]. Cathode (oxygen electrode) is the key component of Li–O2 battery, since the major battery reactions i.e., oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) occur at its surface. However, low round-trip efficiency, poor reversibility and poor power capability are the major challenges faced by the cathodes of the Li–O2 battery [2].
Although the carbon has been generally considered as a good cathode material in Li-O2 batteries because of its advantages such as good chemical stability, high conductivity and versatile porosity, however, it may suffer from the corrosion/oxidation at high potentials in the charging process and promote the electrolyte decomposition accompanying various side reactions during cycling. Therefore, it is strongly required to find out the alternative cathodes to circumvent side reactions involving carbon based materials. To resolve this problem, one possible solution is to suppress the direct exposure of carbon surface to the aprotic electrolyte by uniform coating of non-carbon material on the carbon surface.
In the present work, we report spinel NiCo2O4-deposited CNT (carbon nanotube) bucky paper as a cathode for Li-O2 batteries. To passivate the surface of CNT buckypaper to be attacked by Li2O2 and super radicals, the CNT bucky paper cathode was uniformly coated by metal-oxide (NiCo2O4) layer using simple hydrothermal method. The structural properties of the oxide-deposited CNT cathode are characterized and the electrochemical performances of Li-O2 battery constructed with that cathode are evaluated. The oxide-deposited CNT cathode shows high specific capacities and remarkably reduced charge potentials (in comparison with a carbon-only cathode) as well as excellent cyclability, which suggests that the deposited oxide layer on the surface of CNT effectively reduces the amount of carbonates generated on the surface of carbon.

Reference

[1] A. C. Luntz, B. D. McCloskey, Chem. Rev., 114 (2014) 11721.
[2] I. Landa-Medrano, R. Pinedo, N. Ortiz-Vitoriano, I. R. Larramendi, T. Rojo, ChemSusChem, 8 (2015) 3932.
Towards p-Type Conductivity in SnO2 Nanocrystals through Li Doping and Its Applications in Porous Diodes for Room Temperature Chlorine Gas Detection
Authors: Chaparadza Allen , Rananavare Shankar 
Published: February 2020

This work examined electrical transport properties and Li doping in SnO2 synthesized by the sol–gel method. Solid-state 7Li-NMR line shapes revealed that Li ions occupy two distinct sites with differing dynamic mobilities. The chemical exchange rate between the two sites is, however, too slow for detection on the NMR timescale. Compressed nanoparticulate films of this doped semiconductor exhibited a positive Seebeck coefficient implying a p-type conductivity. A variable-temperature direct current conductivity, over a 25–350 °C temperature range, followed an Efros–Shklovskii variable range hopping (ES-VRH) conduction mechanism (ln(ρ) versus T
−1/2) at temperatures below 100 °C with a crossover to 2D Mott variable range hopping (M-VRH) (ln(ρ) versus T
−1/3) conduction at temperatures above 250 °C. In a transition region between these two limiting behaviors, direct current resistivity exhibited an anomalous temperature-independent plateau. We suggest that its origin may lie in a carrier inversion phenomenon wherein the majority carriers switch from holes to electrons due to Li ion expulsion from the crystalline core and creation of oxygen vacancies generated by loss of oxygen at elevated temperatures. Using a compression technique, porous diodes consisting of n-type (antimony doped SnO2) and the p-type (lithium-doped) nano-particulate films were prepared. Typical current-voltage curves of such devices resembled the behavior of a typical diode but for one key difference; owing to the porosity of the film, areas near the p-n interface and the p- and n-regions are accessible to gaseous analytes. This access is not possible in conventional diodes fabricated through contemporary planar technology. The gas sensing properties of the diodes were investigated by using Cl2, Br2, HCl, NO, NO2, CHCl3, NH3 and H2. Of all the gases tested, the sensor had very good sensitivity to Cl2 and had a response of 80 at 400 ppb of Cl2. The response time of the sensor was ~30 s at room temperature but the recovery time was temperature dependent. At room temperature the recovery time was 80s after 400 ppb chlorine exposure. The sensors were also found to recover quickly (~ 30 s) when the junctions were biased. Reverse biasing the diode provides a controllable band-bending at a p-n junction that could influence the electron-transfer rates from the adsorbates which create intra-band localized states. As a result reverse biasing can provide a means of desorbing the analyzed species. This approach eliminates the requirement to remove adsorbates by elevating the sensor temperature and hence improves on the energy efficiency of these types of sensors.
(Invited) Rapid Formation of Single-Cell Pairs for Hybrid Cells
Authors: Yasukawa Tomoyuki , Mizutani Fumio 
Published: February 2020

Dielectrophoresis (DEP) has been used as a manipulation tool for a separation, sorting and patterning of particles and cells. We have used negative-DEP (n-DEP) which directs particles and cells to form line patterns with particles and cells rapidly toward the localized positions with relative weak electric fields. In this presentation, a microwell array electrode was used to produce vertical pairs with two different types of cells by positive-DEP (p-DEP).
A microwell array (250,000 wells, 500 × 500) was fabricated on a substrate with indium tin oxide (ITO) layer by coventional photolithography. Microwells were designed in 16 μm width and 25 μm depth. Another ITO substrate was mounted on the microwell array via 30 μm thick polyester film to form a fluidic channel.
Mouse myeloma cells (4.0 × 107cells/mL, 12 μm diameter) stained in blue with Hoechst 33342 were introduced into the fluidic channel. AC voltage (1.0 MHz, 10 Vpp) was immediately applied between the upper ITO and lower ITO with microwell array to guide cells in individual microwells by p-DEP. On applying the AC voltage, the dispersed cells immediately, i.e., within 1 s, stayed at positions with microwells. In the microwells trapped with two cells, cells in the top component were removed by the fluidic flow, but cells in the bottom component were retained in the microwells because the fluidic flow could not remove cells from microwells with a depth of 25 μm, i.e., twice the cell diameter or more. These results clearly indicate that the cell array could be formed on the microwell array electrode easily and rapidly by p-DEP.
K562 cells (15 μm diameter) stained in green with 5-(and-6)-carboxyfluoresein diacetate succinimidyl ester (CFDA SE) were also guided into microwells occupied with myeloma cells in blue by p-DEP. Myeloma cells in blue and K562 cells in green were successively trapped into microwells by p-DEP. The presence of two cells is not particularly clear in the optical image. In contrast, both blue and green signals which are indicated the presence of myeloma cells and K562 cells are clearly observed from the individual microwells. These results strongly indicated that two different types of cells are vertically aligned in microwells to form single-cell pairs. We can obtain pairs of different cells within 1 min with the pairing efficiency of approximately 68 %. The vertical alignment of cell pairs would be a distinct advantage for producing couplets by cell fusion using electric pulse fields generated between the upper electrode and the lower microwell array electrode, which were used for the cell pairing by p-DEP. The array of two different types of cells can be easily and rapidly formed using the simple device with a p-DEP process.

Figure 1
Performance of Whole-Cell Electrochemical Biosensor Using Integrated Microbes/Si Nano-Forest Structure
Authors: Mintz Hemed Nofar , Yoetz-Kopelman Tal , Convertino Annalisa , Shacham-Diamand Yosi 
Published: February 2020

Integrating microbial cells on Si nano-forest is a new structure combines whole cell biosensors with a functional nanostructured electrode. Such structure produces a unique electrochemical impedance spectrum in response to charged immobilized microbes. That signal, which is observed by both Nyquist diagram and the Bode plot was investigate in the current research.
Microbial biosensors are widely used for toxicity measurements, food monitoring e.g. sensing of alcohol, glucose, or fatty acids, environmental monitoring, monitoring of microbial growth rate, and biocide measurements. Microbial cells can generate a widespread selective responses to chemical and biological reactions. Utilization of this advantage can yield specific sensors and allay one of the major challenges of chemical and biological sensor design. Moreover, the use of lives cells allows for label-less, non-destructive real-time monitoring of the biological reactions as they develop, with no require for preparatory and analytical steps such as staining or hybridization.
Bacterial cells were genetically engineered to display ZZ protein on the surface of their cell (a kind gift from Prof. Benhar lab). Z domain is a small engineered protein of 58 amino acids, analog of Protein A B domain, originally developed as an affinity-purification ligand. ZZ fragments exhibit high affinity (~10-8M) to Fc region of human IgGs, higher than the affinity of a single Z domain. Each Z domain interact with two distinct sites of the Fc region. Expression and display of Z domain in E.coli was demonstrated before.
The combination of nanostructures, such as Si nanowires (SiNWs), with bacterial cells offers new and unique opportunities to develop novel biosensors. Usually in biosensors, microbial cell immobilized to a planar electrode, consequently part of the displayed charge on the surface of the cell is screened by the electrode itself. This screening effect is decreasing while using SiNWs structure to bind the microbial cells.
We present a study of highly dense, disordered, and randomly oriented ensemble, i.e. Si nano-forest. This Si nanostructured was deposited using relatively low cost and scalable techniques, such as Plasma Enhanced Chemical Vapor Deposition (PECVD), at low temperature (below 350°C); this enables deposition on various substrates including flexible polymeric substrates. Si nano-forest were functionalized using rabbit anti mouse IgG as binding receptor for ZZ protein. EIS measurements were performed, at the range of 0.1 Hz to 200 kHz, in phosphate buffer saline (PBS) solution using potentiostat/galvanostat (VSP®, BioLogic science instruments Ltd.). Modeling was preformed using EC-LAB software. Our results confirm that Si nano-forest electrodes can serve as a sensitive and specific whole cell biosensor.
Optimization of GaN-Based HEMTs for Chemical Sensing: A Simulation Study
Authors: Sciullo Madeline , Choudhury Mohua , Patrick Erin , Law Mark E 
Published: February 2020

Gallium Nitride (GaN)-based High Electron Mobility Transistors (HEMT)s have been shown to be a viable solution for a myriad of chemical and biological sensing applications (e.g., pH sensing, prostate cancer, and breast cancer detection). Modulation of the conducting channel in response to charge adsorbed on the un-metalized gate contact provides a sensitive mechanism for detection of chemical species. Despite numerous experimental studies on these devices, general design considerations such as the role of bias conditions or length-scales on the device operation have not been fully explored. This work makes use of TCAD simulation to identify key parameters for sensor optimization.
Simulation of the general case of one reacting species adsorbing to the open-gate area of an AlGaN/GaN HEMT is performed. Our simulation framework –the Florida Object Oriented Device Simulator (FLOODS)– is specifically suited for III-V device simulation and is capable of self-consistent, fully-coupled simulation of reaction-dependent physics at the electrolyte/semiconductor interface. Simulation results in Figure 1.a show a linear trend of increasing sensitivity with gate length over a range of 0.1 to 1.5 μm. This result predicts an obvious increase in sensitivity with an increase in active sensing area. It is also shown in Figure 1.b, for the first time, how the linearity of the device sensitivity is highly dependent on gate length, or active surface area. This work delves in to the physical mechanisms that play a role in sensor parameters such as linearity and identifies optimum bias conditions for single-ion chemical sensors, in general.
Figure 1. Simulation results for a bias condition of Vds=4V and unbiased gate. (a). Peak sensitivity as a function of gate length. (b). Sensitivity as a function of ion concentration. The linearity of device is dependent on gate length.

Figure 1
Preparation of Li4Ti5O12 Nanosheets/Carbon Nanotube Composites and Application of Anode Materials for Lithium-Ion Batteries
Authors: Diao Guowang , Zhang Pengfei , Chen Ming 
Published: February 2020

ABSTRACT:

Li4Ti5O12
nanosheets (LTO NSs)/carbon nanotubes (CNTs) composites are synthesized using a facile, reproducible, and scalable strategy. In the hydrothermal process, the introduction of CNTs significantly improves the rate performance of LTO NSs. The incorporation of CNTs into the LTO NSs forms a delicate conductive network for rapid electron and lithium ions transport, resulting in excellent rate performance and superior cycling performance. LTO NSs/7.5%-CNTs composites show the highest reversible capacity and high-rate capability (a reversible capability of 157, 145, 132, 118, and 105 mA h g-1 at 1, 2, 3, 4, 5 A g-1, respectively) with good cycling performance (approximate 6.9% capacity loss after 1000 cycles at 2 A g-1 with a capacity retention of 135 mA h g-1), which is apparently larger than pristine LTO NSs. The significantly improved rate capability and cycling performance of the LTO NSs/CNTs composites are mainly attributed to their the lower polarization of potential difference, the larger diffusion coefficient of lithium ion and smaller charge-transfer resistance than pure LTO NSs.

Keywords: Lithium titanate nanosheets; Carbon nanotubes; Rate performance; Lithium ion diffusion; Lithium ion batteries

References

[1] Y.-Q. Wang, L. Gu, Y.-G. Guo, H. Li, X.-Q. He, S. Tsukimoto, Y. Ikuhara, L.-J. Wan, Rutile-TiO2 Nanocoating for a High-Rate Li4Ti5O12 Anode of a Lithium-Ion Battery, J. Am. Chem. Soc. 134 (2012) 7874-7879.
[2] G. Xu, W. Li, L. Yang, X. Wei, J. Ding, J. Zhong, P. Chu, Highly-crystalline ultrathin Li4Ti5O12 nanosheets decorated with silver nanocrystals as a high-performance anode material for lithium ion batteries, J. Power Sources 276 (2015) 247-254.
[3] B. Li, C. Han, Y.-B. He, C. Yang, H. Du, Q.-H. Yang, F. Kang, Facile synthesis of Li4Ti5O12/C composite with super rate performance, Energy Environ. Sci. 5 (2012) 9595-9602.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (Grant No. 21273195, 21511140282), a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions. The work was also sponsored by Qing Lan Project of Higher Learning Institutions in Jiangsu Province, the support of high-end talent plan of Yangzhou university, and Jiangsu Key Laboratory of Environmental Material and Environmental Engineering (K11032). The authors also acknowledge the Testing Center of Yangzhou University for SEM, TEM, XRD, and Raman experiments.
Nano-Biosensors: An Advanced and Essential Tool in Monitoring Microcystins in Water
Authors: Vogiazi Vasileia , Zhang Lu , Zhao Daoli , Alvarez Noe , Chae Soryong , Sagle Laura , Heineman William R. , Shanov Vesselin N. , Papautsky Ian , Dionysiou Dionysios D. 
Published: February 2020

Freshwater contamination during extensive algae blooms with their cyanotoxins represents a significant global concern for public health. In 2014, algae blooms have significantly affected drinking water supply in the Toledo (OH, USA). Due to similar threatening incidents, the U.S. Environmental Protection Agency (USEPA) was urged to release a ten-day drinking water health advisory for cyanotoxins. In June 2015, USEPA advised very low concentrations for children consumption that may reach the 0.3 μg/L for microcystin-LR. In the fall 2015, Ohio River contamination exceeded the 650 miles along the river. These incidents along with the strictness of advisories and regulations urge the development of a portable, simple and highly selective monitoring tool to measure the lowest possible microcystins’ concentration in various water sources. Our team utilize attractive InterDigitaded array (IDA) gold and graphene-based electrodes to demonstrate their capabilities in detecting microcystins in drinking water. In this study, electrochemical nano-biosensors based on three dimensional (3D) graphene were made, functionalized and characterized. The novel 3D graphene paper exhibits high electrical conductivity, and large specific area, which ensures high charge-transfer rate and good sensitivity for microcystin detection. Cyclic voltammetry and impedance spectroscopy were used to explore the interfacial phenomena of gold IDA and the 3D graphene biosensors.