bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecularly Imprinted Voltammetric Sensor Based on Chitosan-CNTs Decorated with AuNPs Nanocomposite for Catechol Detection
Authors: Salvo-Comino Coral , Rassas Ilhem , Minot Sylvain , Bessueille Fancois , Arab Madjib , Rodriguez-Mendez Maria Luz , Errachid Abdelhamid , Jaffrezic-Renault Nicole
Published: May 2020

This research is based on the development of a novel, biocompatible and sensitive electrochemical imprinted sensor based on the detection of a phenolic compound, such as catechol, employing electroactive nanomaterials with the objective of improving the electron transfer between the electrode surface and the solution [1] and a natural biopolymer due to its excellent layer forming ability [2]. The development of the sensor is based on the modification of multiwalled carbon nanotubes (MWCNTs) with gold nanoparticles (AuNPs). The decorated MWCNTs have been recovered with a polymeric chitosan (CS) matrix generating a nanocomposite that contains the electroactive material inside. The polymeric matrix of CS that holds the modified MWCNTs has been electrodeposited in the presence of the phenolic compound on a boron doped diamond (BDD) electrode. The sensor surface has been structurally characterized to demonstrate the correct adsorption of the film and the correct recovery of the decorated carbon nanotubes on the BDD electrode surface. The performance as an electrochemical MIP sensor analyzed by cyclic voltammetry has offered excellent characteristics, demonstrating a high affinity to catechol with high selectivity, reproducibility, repeatability and sensitivity in the range of catechol concentrations from 0 to 1 mM. Finally, the implementation of the sensor to measure in a complex red wine sample has been carried out. The obtained results have resulted to be successful to quantify catechol in the real matrix. For these reasons, the proposed research manifests a promising and interesting way to implement an imprinting biocompatible polymers method in the development of an electrochemical sensor for phenols detection in the 4.0 industry.

[1] S. A. Zaidi, Sensors Actuators B. Chem., 2018, 265,488-497.

[2] A. Gopalan, S. Komathi, N. Muthuchamy, K. Lee, M. J. Whitcombe, L. Dhana, y G. Sai-anand, Prog. Polym. Sci., 2019 88, 1-129.

Acknowledgments: Financial support by MINECO and FEDER (RTI2018-097990-B-100 and BES-2016-077825) and the Junta de Castilla y León-FEDER (VA-275P18) is gratefully acknowledged.
Waste-Biomass-Derived Carbon As Renewable Electrode Materials for Plant Microbial Fuel Cells
Authors: Lin Fang-Yi , Liu Tzu-Yin , Chen Han-Yi
Published: May 2020

Developing clean and sustainable energy sources is important as it deals directly with energy shortage and environmental pollution problems caused by fossil fuels. Plant microbial fuel cells (PMFCs) is a novel technology that can convert solar energy into electrical energy by the microbes at the region of rhizosphere of the plants. Without producing any harmful byproducts during the energy generation process, PMFCs seems to be a promising choice as a renewable power supply technique. Green carbon materials, utilizing agro-industrial waste as precursors, has attracted lots of interest in research recently on account of them being environmental friendly materials and mitigating bio-wastes.

To combine the advantages of PMFCs and green carbon materials, the aim of this study is to optimize the electrochemical performance of our designed PMFCs by utilizing biowaste-derived activated carbon materials as the electrode materials. The biowaste-derived activated carbon materials were characterized by Brunauer-Emmett-Teller (BET) surface area analyzer, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of PMFCs devices developed by ourselves were analyzed through linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). This study set out to examine the relationship between the properties of activated carbon and the electrochemical performance of PMFCs, expecting to develop a high power density PMFCs device.
A Molecular Dynamics Study of Na Ion Transport and Storage inside Nanoporous Carbon Electrode for Na-Ion Batteries
Authors: Park Sungwon , Fabiyi Victor Abolarin , Paek Eunsu
Published: May 2020

Hard carbon has emerged as an attractive anode material for sodium ion batteries (NIBs) because of its low cost, high initial coulombic efficiency, high specific capacity, and steady cycling performance. Based on combined molecular dynamics (MD) simulation and density functional theory (DFT) calculations, we present an atomistic description of the electrolyte-electrode interaction of sodium hexafluorophosphate (NaPF6) in mixed ethylene (EC) and dimethyl carbonate (DMC) electrolyte inside nanoporous carbon electrode. We investigate the microstructure of electrolyte in carbon nanopores with an average pore size of 8.9 Å and a specific surface area of 1794 m2g-1 at 0 V and 2 V to gain molecular insight into electrolyte behavior such as solvent packing, preferential adsorption sites, and solvation structure. Our simulation suggests good accessibility of carbon nanopores by electrolyte molecules upon charging. At 2 V, Na+ is desolvated and intercalates into highly confined carbon structures as a result of the strong interaction between Na+ and charged carbon atoms while PF6
- occupies weakly confined carbon nanostructures by forming ion pairs with Na+. Also, we examined the various levels of confinement of electrolyte components using a degree of confinement (DoC) analysis, and present the effects of confinement on electrolyte properties. Our calculations show a 29 % reduction in Na+ adsorption distance for a nanoporous structure compared to a planar structure of carbon, and the preferential adsorption of Na+ at a hydrogen-terminated edge of porous carbon with an adsorption energy of -0.27 eV compared to a basal site with a higher adsorption energy of 0.02 eV. Finally, an investigation of the solvation sheath structure as a function of DoC shows decreased solvation shell, shortened adsorption distances, and increased counter-charge with increasing DoC.
Electrochemical Oxidation of Organic Fuels at Rotating and Flow through Electrodes
Authors: Sayadi Azam , Pickup Peter G
Published: May 2020

Oxidation of small organic molecules (SOM) has been one of the most active targets of investigation in electrochemistry for several decades. One of the main reasons is that SOM such as formic acid, methanol, and ethanol, can be used to produce electrical power through their oxidation in fuel cells [1]. These devices have the potential to produce close to 100% energy efficiency in theory. However, practically this level of efficiency has not been achieved for SOM so far due to deficiencies such as slow and incomplete oxidation of the fuel. For enhancement of the energy efficiency, a comprehensive study of the electrocatalytic oxidation mechanisms and average number of exchanged electrons of SOM as fuels are fundamental. One of the widespread approaches for these studies is applying hydrodynamic methods due to their ability to emulate the hydrodynamic conditions of a fuel cell anode.

We have applied rotating disc voltammetry (RDV) and flow cells to study the electrocatalytic oxidation of ethanol, methanol and formic acid. Using RDV the measured current can be separated into its kinetic and mass transport components and this provides reproducible and controllable conditions for kinetic and mechanistic studies [2]. The number of electrons transferred for ethanol oxidation at room temperature was found to be ca. 3.5 [3], which agrees with literature reports of product distributions. Also, we showed that accurate kinetic currents could be obtained for formic acid oxidation using RDV [4]. One hundred percent faradaic efficiency and a diffusion coefficient in good agreement with literature values were obtained for methanol oxidation at a PtRu black catalyst using RDV [5]. Our next approach was to design a flow-through electrolysis cell in order to evaluate the reliability of findings from RDV by product analysis. The organic fuel solution passes through the working and counter electrodes in line, and the cell exhaust is collected for spectroscopic analysis by H-NMR. Also, a CO2 detector was used for real-time measurements. Despite its simple design, this flow cell can provide valuable information regarding the kinetics and stoichiometry of catalytic electrooxidation of organic fuels.

[1] G. L. Soloveichik, Beilstein, J. Nanotechnol,
5, 1399–1418 (2014).

[2] A.J. Bard, L.R. Faulkner, Electrochemical methods. Fundamentals and applications, 2nd ed. 2001, Weily, New York, (2001).

[3] A. Sayadi and P. G. Pickup, Electrochimica Acta, 215, 84-92 (2016).

[4] A. Sayadi and P. G. Pickup, Electrochimica Acta,
199, 12-17 (2016).

[5] A. Sayadi, and P. G. Pickup, Special V. G. Levich Issue of Russ. J. Electrochemistry, 53, 1183–1192 (2017).
In Situ Observations of Molecular CO2 Interaction on SnS2 Thin Film for Gas-Phase Photocatalytic CO2 Reduction Activity
Authors: Reta Tadesse Billo , Shown Indrajit , Lee Chih-Hao , Chen Kuei-Hsien , Chen Li-Chyong
Published: May 2020

Among the several approaches, the gas phase photocatalytic conversion of CO2 to useful fuels with the help of renewable energy sources and water vapor has attracted widespread attention. In this system, the gas-solid interaction between a CO2 molecule and a solid catalyst surface is a crucial step. However, the adsorbate-catalyst surface interaction in the gas-phase of CO2 reduction system on the surface of semiconductor photocatalysts remains unaddressed.

In this report, high-quality SnS2 thin film was prepared through a chemical vapor transport process followed by controlled carbon implantation to form C-SnS2. Our material design and characterization approaches, which involve in-situ observations enabled us to correlate the adsorbate-catalyst surface interactions and their implications on photocatalytic CO2 reduction. Using in-situ dark current and in-situ Raman spectroscopy, under different gas ambient conditions, we have observed that, the C-SnS2 surface exhibited a strong affinity towards CO2 molecule and higher photon to electron conversion efficiency under light illumination. In addition, the optimized carbon implanted SnS2 sample has demonstrated more than 108 times enhancement in the CO2 conversion efficiency and about 89% product selectivity towards CH4 formation. Additional information on the mechanism of interfacial charge transfer was obtained using angle-dependent XANES, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) analysis.

We anticipate that the adsorbate-catalyst surface interaction studies applied in this report can be extended to be used as a benchmark in design and material selection in the gas-phase CO2 photoreduction applications. We further expect that C-SnS2 with its promising photocatalytic performance and high affinity toward CO2 adsorption and activation; will inspire the development of new semiconductor photocatalysts by modifying it with metal or non-metal dopants towards CO2 conversion into useful products. The detail characterization and experimental results with the future perspective of this study will be presented.
Influence of Pd Decoration on Carbon-Based Nanomaterials Towards Electrochemical Hydrogen Storage
Authors: Boateng Emmanuel Q. , Dim Vincent , Chen Aicheng
Published: May 2020

The growing need for deep decarbonisation of current global energy systems makes hydrogen-based economy an attractive option for the future. For the envisaged hydrogen economy to be commercially accessible, the challenge for hydrogen storage must be addressed. Solid-state hydrogen storage has received tremendous research interest due to its advantages, such as low cost, high efficiency, safety and high volumetric storage capacity [1,2]. In this study, different carbon-based materials were synthesized and characterized for hydrogen storage. The effect of the modification of those carbon-based materials with Pd nanoparticles was investigated. The significant enhancement of the hydrogen storage capacity is presented

References:

[1] L. Schlapbach, A. Züttel, Hydrogen-storage materials for mobile applications, Nature 414 (2001) 353–358.

[2] E. Boateng, A. Chen, Recent advances in nanomaterials-based solid-state hydrogen storage, Mater. Today Adv. (2019) in press.
Synthesis of Nanostructured Cobalt-Based Catalysts for Electrochemical Carbon Dioxide Reduction
Authors: Abner Sharon , Chen Aicheng
Published: May 2020

The continuous rise in carbon dioxide (CO2) concentration in the atmosphere is known to be one of the main causes of global climate change. The use of CO2 as a precursor in the production of synthetic fuels and other industrial chemicals offers a way to mitigate climate change. The direct conversion of CO2 to industrial low-carbon chemicals, such as carbon monoxide, formate and methane, using electrochemical approaches has attracted attention [1]. One of the main challenges encountered is overcoming the high activation energy required to convert surface adsorbed CO2 into CO2
•− which leads to high overpotential. The search for a cost-effective non-noble metal has led to the exploration of cobalt-based materials as a viable catalyst for CO2 reduction reaction. Although, Co is widely used as a catalyst for electrochemical water splitting [2], recent findings shows that Co and Co-oxides can lead to the reduction of CO2 to CO and formate with high faradaic efficiencies [3, 4]. In this study, different Co-based nanomaterials including nanoparticles and nanodendrites were synthesized. The formed nanomaterials were studied using a wide range of surface characterization techniques and electrochemical methods. The catalytic activity of the synthesized Co-based nanoparticles and nanodendrites towards the electrochemical reduction of carbon dioxide will be compared and discussed.

References:

[1] A. S. Agarwal, Y. Zhai, D. Hill, and N. Sridhar, ChemSusChem 4 (2011) 1301–1310.

[2] J. Cirone, S. R. Ahmed, P. C. Wood, and A. Chen, J. Phys. Chem. C 123 (2019) 9183 - 9191.

[3] G. Yin, X. Yuan, X. Du, W. Zhao, Q. Bi, and F. Huang, Chem. - A Eur. J. 24 (2018) 2157–2163.

[4] S. Gao et al.
Nature 529 (2016) 68–71.
Screening Ternary Pt-Based Electrocatalysts for Oxygen Reduction Reaction By Scanning Electrochemical Microscopy
Authors: Weng Yu-Ching , Wang Hsin-Jen
Published: May 2020

Developing efficient electrocatalysts for oxygen reduction is effective to reduce the overpotentials in cathode for PEMFC and metal-oxygen battery. A high-throughput approach for developing materials is revolutionizing the current trial-and-error mode with great potential for accelerating the process. The aim of the study is screening ternary Pt-based electrocatalysts for oxygen reduction reaction (ORR) by scanning electrochemical microscopy (SECM) with tip generation-substrate collection (TG-SC) mode. Oxygen was generated at a tip and reduced at the electrocatalyst spots on substrate. Among several ternary Pt-based electrocatalyst arrays, Pt8Ni2Co0, Pt2Fe4Cu4, Pt6Mn2Mo2, Pt8Al2Tl0, Pt6V2Ga2 exhibit excellent electrocatalytic activity for ORR. The structure, morphology and oxidation state of these potential electrocatalysts are systematically studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The tip/substrate voltammetry, approach curves and rotating disk electrode analysis are further used to examine the kinetics of the potential electrocatalysts toward oxygen reduction reaction.
Studies on the Mechanism of Electrochemical Detection of Haemophilus Influenzae at Diamond-Based Electrodes
Authors: Kowalski Marcin Krzysztof , Brodowski Mateusz , Dziąbowska Karolina , Dettlaff Anna , Bogdanowicz Robert , Nidzworski Dawid
Published: May 2020

Haemophilus influenzae (HI) is a Gram-negative pathogenic bacterium whose infections occur worldwide and mainly affect unvaccinated children and those who have not completed the basic vaccination course. Type B of this bacterium (Hib) can cause sepsis, and other invasive diseases as dermatitis or arthritis but the most dangerous is pneumonia meningitis. The most reliable method for recognizing Hib infections is isolation in microbiological culture. Serological tests are also performed to diagnose Hib infections. They rely on the detection of the presence of bacterial antigens or antibodies which have the ability to bind to specific antigens. Detection of antibodies doesn’t mean disease but only indicate contact with a given bacterium in the past. Recognition of bacteria using presently known methods takes a long time and requires expensive equipment although fast and sensitive detection of Haemophilus influenzae is crucial l to start treatment early enough.

In this work, we present electrochemical detection of HI on diamond-based pastes electrodes using binding specific antibodies (ap. D) with proteins occurring on the surface of bacteria (protein D). The measuring system consisted of a specially prepared printed circuit board (PCB) and diamond-based electrode, which was prepared by screen printing in special conditions. Places printed on it, served as a working electrode, counter electrode and reference. Ceramics was first used as a substrate, but it was quickly changed to Teflon, which showed better adhesion to diamond pastes. Better sample strength was also obtained, so it could be washed in an ultrasonic cleaner without fear of damage. Before detection, the electrode had to be modified by electrochemical reduction of the aminobenzoic acid diazonium salt, antibodies deposition via EDC / NHS and blocking the unmodified electrode sites by incubating in solution of Bovine Serum Albumin (BSA). The last step of modification prevents unspecific adsorption on electrode surface which would lead to false detection results.

Electrochemical Impedance Spectroscopy Fig. 1) were used to bacteria detection. The electron transfer resistance rises with each step of electrode modification and increased bacterial concentration in solution. Then a calibration curve was constructed.

Three pathogens were selected to check the biosensor selectivity: S. pyogenes, S. pneumoniae, B. parapertussis. For each pathogen responses were significantly lower than for HI at similar concentrations. For example, the response of sensor for S. pyogenes (67474,28 CFU/ml) and B. parapertussis (17819,27 CFU/ml) were less than 5%, which are much smaller in comparison to response at level of 30% for HI (47003,48 CFU/ml).

Acknowledgments

The authors gratefully acknowledge financial support from the National Centre for Science and Development Grant Techmatstrateg No. 347324 2015/16/T/ST7/00469.

Figure 1
Effects of Na2s, NaCl, and CuCl2 Concentrations on the Corrosion of Aluminum
Authors: Lee Juhee , Jang Heejin
Published: May 2020

The corrosion behavior of aluminum in the mixed solution of Na2S, NaCl, and CuCl2 was investigated by potentiodynamic polarization tests and statistical analysis based on DOE (Design of Experiment). The effects of ions on the corrosion potential, the corrosion rate, and the pitting potential of aluminum were analyzed to elucidate the main effect and interactions between ions.
Segmented Phosphonium Ionenes As Solid Polymer Electrolytes for Lithium Ion Batteries
Authors: Strong Kayla , Abdulahad Asem
Published: May 2020

All-solid-state lithium ion batteries replace the traditional liquid electrolyte with a conductive solid polymer electrolyte. Replacing the liquid electrolyte in batteries has the potential to improve safe use of batteries without the need for hermetic sealing, extending the operating temperature range, and extending the lifetime of the battery. However, solid polymer electrolytes often have non-competitive conductivity compared to liquid electrolytes. Improving the conductivity of solid polymer electrolytes based on an understanding of structure-property relationships is not yet well understood, but it is believed to depend heavily on the localized segmental motion of polymer chains. This work attempts to describe the role of polymer segmental motion on lithium ion transport through the synthesis and characterization of phosphonium ionenes that include poly(ethylene oxide) “soft” segments. Synthetically, these segmented polymers offer an opportunity to systematically control the segmental motion of polymer chains (i.e. glass transition temperature) through control of PEO incorporation. Prepared by step-growth polymerization, these segmented phosphonium ionenes achieve molecular weights up to 40,000 g/mol. Also, the degradation and glass transition temperatures are dependent on the percent incorporation of PEO as determined by thermogravimetric analysis and differential scanning calorimetry, respectively. The ability to influence the physical properties of this unique class of polyelectrolyte provides a unique opportunity to systematically probe the impact of glass transition temperature on the ion transport properties of solid polymer electrolytes in lithium ion batteries. Our initial results from electrochemical impedance as well as the charge/discharge performance of these novel solid polymer electrolytes in coin cell battery assemblies will also be presented.
Hydrogen Storage Properties of Melt Spun Mg-Based Alloy through Electrochemical Method for Ni-MH Batteries
Authors: Bhatt Priyanka , Hazan Joseph , Huot Jacques
Published: May 2020

Magnesium-based alloys have attracted much attention and extensive research as negative electrode materials for Ni/MH batteries. Magnesium alloys are low cost and they have high discharge capacity in electrochemical processes1. However, corrosion behaviour severely limits their utilization. Magnesium alloys are also considered as hydrogen storage materials due to their high hydrogen capacity. In this communication, the crystallographic, morphology and electrochemical properties of melt spun Mg74Zn22Nd4 will be reported. It was found that, despite the ribbon being very thin (0.10 mm), the microstructure on each side of the ribbon is different. The surface touching the wheel is showing a much higher crystallinity and texture than the other face of the ribbon. In the same way, morphology on both faces are different. The electrochemical hydrogen storage behaviour in addition to gas phase absorption/desorption will be discussed.

[1] Li-FangJiao, Hua-TangYuan, Yi-JingWang, Yong-MeiWang, International Journal of Hydrogen Energy. 34 (2009) 1476–1482
Mn5O8/GO and MnO2/GO Nanocomposites As Cathodes for Li-Ion Battery
Authors: Blanchard Samantha , Moazzen Elahe , Timofeeva Elena V. , Segre Carlo U.
Published: May 2020

In this study Manganese Dioxide (MnO2) nanoparticles with the polymorph composition of ramsdellite (31 wt%) and akhtenskite (69 wt%) were synthesized and used to develop enhanced cathode nanocomposites for Lithium-ion batteries (LIBs). The MnO2 nanoparticles were wrapped with graphene oxide (GO) and annealed under N2 to reduce oxygen functionalities. The temperature of annealing and concentration of GO were investigated for optimized performance. The crystalline structure and electrochemical performance of the products were characterized by x-ray diffraction (XRD)/Rietveld refinement and electrochemical tests i.e. galvanostatic cycling, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results suggest that the composites annealed at 225 °C results in collapse of 1 x 2 channels to 1 x 1 channels, which is facilitated more with increasing the GO concentration. The GO/MnO2 composite with 7 wt% GO annealed at 225 °C showed the best specific capacity enhancement. By annealing the composites at 400 °C, the core MnO2 is converted to Mn5O8 with a layered structure, which has not been studied as a cathode for LIBs to the best of our knowledge and showed significantly enhanced capacity retention. Rietveld results suggest that Mn3O4 grows in the structure as the result of increasing GO wt% in composition at 400 °C, which results in lower capacity.
Work Function Extraction of BCN Thin Films from BCN/n-Si Heterojunction Devices
Authors: Nehate Shraddha Dhanraj , Saikumar Ashwin Kumar , Sundaram Kalpathy B.
Published: May 2020

Boron carbon nitride (BCN) has gained attention due to its structural similarity to carbon and boron nitride. BCN compounds are known to combine excellent properties of B4C and BN, with properties being adjustable depending on elemental composition[1, 2]. BCN is a low-k material (k=2.13) and very high breakdown strength (~3.4 MV/cm). Additionally, the ability to control band gap by atomic composition and structure makes BCN films suitable for applications in electronic and optical devices[3].

In this study, BCN/n-silicon heterojunctions are fabricated using RF sputtering technique. Work function of BCN thin films are extracted from I-V characteristics. I-V characteristics are obtained for operation at temperatures from 25 to 200 °C. Using this method, parameters such as barrier height, ideality factor, rectification ratio are investigated.

References

[1] A. Prakash, K. B. Sundaram, and Technology, "Studies on electrical properties of RF sputtered deposited boron carbon nitride thin films," vol. 4, no. 5, pp. N25-N29, 2015.

[2] A. Prakash, S. D. Nehate, and K. B. Sundaram, "Boron carbon nitride based metal-insulator-metal UV detectors for harsh environment applications," vol. 41, no. 18, pp. 4249-4252, 2016.

[3] H. Aoki et al., "Influence of moisture on BCN (low-K) film for interconnection reliability," vol. 17, no. 4-5, pp. 628-632, 2008.
Work Function Determination of Gallium Doped Zinc Oxide Using Transparent Gate MOSFET Devices
Authors: Saikumar Ashwin Kumar , Phelps Justin , Nehate Shraddha Dhanraj , Abdolvand Reza , Sundaram Kalpathy B.
Published: May 2020

Recent commercialization has peaked interest in transparent conducting oxides being implemented in transparent applications. Gallium doped zinc oxide (GZO) films exhibit excellent transmission characteristics in the visible spectrum while maintaining high electrical conductivity. In majority applications the work function of the material used has an impact on the device performance as it affects the energy barrier height at the hetero-junction interface. Hence, the work function identification is of critical importance.

In this article, we discuss work function extraction of GZO from a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) device for the first time. Four level mask sets were used to fabricate two MOSFET devices following exact same conditions. Source and drain contacts were made using aluminum metal for both MOSFETs. One of the MOSFET was fabricated with aluminum as gate contact and the other MOSFET with transparent conducting GZO as its gate contact. GZO used in this research were RF sputtered. From the threshold voltage equation of both the fabricated MOSFETs, work function of GZO was extracted. The electrical and optical transmission studies were also performed on the sputtered GZO thin films and are reported in this study.
Smart Binders for Silicon Based Composite Electrode in Li-Ion Batteries
Authors: Huet Lucas , Lestriez Bernard , Devic Thomas , Roué Lionel
Published: May 2020

Silicon is one of the most promising alloying anode materials for Li-ion batteries thanks to its high specific and volumetric capacity. In comparison with the commercially available graphite, silicon delivers 10 times higher specific capacity (up to 3600 mA.h.g-1) and 3 times higher volumetric capacity ( up to 2200 mA.h.cm-3) [1]. However, silicon suffers from high volumic expansion upon lithiation (up to 280 %). It induces the pulverization of the micrometric silicon particle, the perpetual solid electrolyte interface renewal and decohesion between constitutive elements of the electrode, drastically reducing its lifespan [2].

To tackle those issues we propose the formulation of composite electrode with improved binder. It is composed of carboxymethyl cellulose sodium salt (NaCMC, as a binding network) and zinc sulfate dissolved in a pH 3 buffer solution (composed of citric acid and potassium hydroxide). The originality and improvement comes from the use Zn2+ ions as coordination agents, binding to carboxylate groups from the CMC and citric acid. Among benefits, we believe that the coordination helps to mitigate the stress inside the electrode because of the improved reticulation of the network, thus improving its resilience [3]. To support this hypothesis, we provide physico-chemical characterizations of the binder as well as the electrochemical performances of our electrodes.

[1] M.N. Obrovac, V.L. Chevrier, Alloy Negative Electrodes for Li-Ion Batteries. Chem. Rev. 2014, 114, 11444-11502.

[2] A. Etiemble, A. Tranchot, T. Douillard, H. Idrissi, E. Maire, L. Roué., Evolution of the 3D Microstructure of a Si-Based Electrode for Li-Ion Batteries Investigated by FIB/SEM Tomography, J. Electrochem. Soc. 2016,163, A1550-A1559

[3] D. Mazouzi, R. Grissa, M. Paris, Z. Karkar, L. Huet, D. Guyomard, L. Roué, T. Devic, B. Lestriez, CMC-citric acid Cu(II) cross-linked binder approach to improve the electrochemical performance of Si-based electrodes. Electrochim. Acta 2019, 304, 495-504.
Molecular Crystallization within the Electrical Double Layer
Authors: Gautam Prakhar , Mweka Cecelia , Fahrenkrug Eli
Published: May 2020

The polymorphic phase of crystals underpins key attributes of drug solubility, bioavailability, stability, and downstream processing. This work aims to model a parallel plate cell on an electrolytic capacitor design to develop large electric fields within the electric double layer interfaces to position paracetamol molecules into Form II orthorhombic polymorphs. Form II has been shown to have higher solubility and is readily compressible into tablets, thus making it more favorable.

The parallel plate electrical double layer cell successfully delivers electric fields on the order of 1 V/nm to a thin layer solution. Electrochemical characterization demonstrates the long-term stability of the cell, dielectric breakdown, and overall electric field intensities that can be applied to solution. Application of this cell to a ring opening epoxide reaction and the resulting modulation of product ratios highlights the effectiveness of the cell. Efforts to affect crystal molecular nucleation are described in the context of supersaturated solutions of paracetamol subject to electric fields for 4-12 hours with temperatures from room temperature to -6 C. Raman spectroscopy and X-ray diffraction characterization of the crystals are used to confirm polymorph identity.
Optical Voltammetry Closed-Cell Bipolar Electrochemistry Based Sensor for Portable Low-Cost Heavy Metal Water Testing
Authors: Monge Jose , Fahrenkrug Eli
Published: May 2020

Events such as the ongoing Flint, MI and Newark, NJ water crises highlight the need for reliable large-scale water quality assurance. Currently available options for water testing such as laboratory analysis and commercial test strips fail to adequately provide a description of potential water issues for they are expensive, time consuming and rely on technical expertise, being practically futile for the layman and for identifying and preventing large water crisis. Our group developed a new analytical apparatus and mechanism for the detection of metals in water, which is portable, quick, accurate, cost-efficient and can be readily adapted for different deployment needs. The apparatus employs a two-step protocol of optical anodic stripping voltammetry in a readily parallelizable closed-cell bipolar electrode format and is produced under a quick and cost-effective fabrication protocol. Additionally, the fabrication utilizes readily adoptable techniques such as laser cutting as opposed to costly clean-room fabrication techniques. The tool can also be further adapted to employ other commonplace technologies such as printers and smartphones. Previous work from this lab had effectively utilized electrochemiluminescence as reporting mechanism but has now moved onto more consistent light-emitting diodes with improved linearity over several orders of magnitude, increased re-usability and limits of detection now in the sub-ppb range. This new sensing scheme utilizes a simple power supply to couple an anodic stripping event at one pole of the bipolar electrode with an LED emission which is externally recorded and processed thereby avoiding additional costly, non-portable conventional potentiostatic circuitry. In this format, near 100% faradaic efficiency can be achieved as well as facile parallelization for simultaneous sensing of multiple electroactive species. The apparatus and mechanism show great promise as a new deployable analytical tool which can be further engineered to non-electroactive species such as PFAs and to even-lower cost techniques and user-friendly protocols for unprecedented large-scale water quality assurance.

Figure 1
Structure and Stability of Cun Clusters (n = 1-4) Adsorbed on Stoichiometric and Defective 2D MoS2
Authors: Nies Cara-Lena , Nolan Michael
Published: May 2020

Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first principle simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first row transition metals, as well as Ag and Au. However, most studies have examined single atom adsorption or adsorb nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first principles density functional theory (DFT) study of the adsorption of small Cun structures, where n = 1-4, on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atom. Stability is driven by the number of Cu-Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances copper binding energy, although some Cun nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally on both the pristine and defective MoS2 monolayer, the density of states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved.
A Study on Processing Parameters Affecting Solid Polymer Electrolytes Performances
Authors: Mankovsky Denis , Lepage David , Ayme-Perrot David , Dollé Mickael
Published: May 2020

In the modern world, the rapid advancement of new technologies is accompanied by an increasing energetic demand. Following today`s trend, energy consumption will undoubtedly increase in the following years. Over the last 50 years, lithium-metal batteries have been considered as potential candidates for long-term high-performance electrochemical storage. (1) Although their operation is effective, they still present limitations mainly due to lithium dendrite growth associated with electrodeposited Li+ from the electrolyte on the anode material. This phenomenon causes internal short-circuits resulting in premature battery failure. (2)

Various solid-state battery systems are being developed in hope to resolve the said issue. Amongst others, solid polymer electrolytes (SPE) have been investigated since Armand`s work in the 80`. (3) Even though these systems have non-flammable properties and successfully suppress dendrite growth, most SPEs do not reach ionic conductivities values higher than 10-3 S/cm at room temperature and offer lower energy densities and cycle number compared to the standard liquid electrolyte counterpart. (4)

As a result of that, an increasing number of published literature shows off new engaging SPE systems. However, oftentimes, the presented performances are hardly reproducible due to the lack of precise and detailed experimental conditions. It is believed that some overlooked factors during processing may affect the aforementioned performances. (5-7) Certain parameters that affect ionic conductivities of SPEs have been investigated by techniques including but not limited to electrochemical impedance spectroscopy (EIS) and solid-state 7Li-NMR. It will be demonstrated that these parameters must be precisely controlled to ensure the reproducibility and the validity of measurements. Finally, it will be shown that this study can be applied to several types of polymers.

1: Hall P. J., Bain E. J., Energy Policy,
36, 4352 (2008).

2: Lisbona D., Snee T., Process. Saf.
Environ., 89, 434 (2011).

3: Armand M. B., Ann. Rev. Mater. Sci. 16, 245 (1986).

4: Penghui Y., Haobin Y., Zhiyu D., Yanchen L., Juan L., Marino L., Junwei W., Xingjun L., Front. Chem., 7, 522 (2019).

5: Fullerton-Shirey S. K., Maranas J.K, Macromolecules, 42, 2142 (2009).

6: Devaux D., Bouchet R., Glé D., Denoyel R., Solid State Ion., 227, 119 (2012).

7: Wang X., Zhang L., Li G., Zhang G., Shao Z.G., Yi B., Electrochim. Acta, 158, 253 (2015)
3D-Printable Ionogels Based on Protic Ionic Liquids for Energy Applications
Authors: Lange Alyna , Zehbe Kerstin , Taubert Andreas
Published: May 2020

In light of the well-known challenges regarding the global energy economy and climate issues fuel cells are widely discussed for their benefits and potential applications in the future. One of the main problems of PEM-fuel cells is that Nafion®-membranes have a limited application temperature window of ≤ 80 °C at ambient pressure due to dehydration and corresponding loss of conductivity at higher temperatures. [1] As a result there is a significant need for new membranes of a precise and defined size and geometry exhibiting significant ion mobilities far above 100 °C.

Based on their highly useful properties like thermal stability, non-flammability, and high ionic conductivities ionic liquids (ILs) are promising components in energy devices such as batteries, solar cells or fuel cells. For proper function of, for example, fuel cell membranes, it is, however, necessary to immobilize the ILs in a polymer matrix, resulting in ionogels (IGs) combining the characteristics of the respective IL with e. g. the mechanical stability of the polymer. [2] The combination of 3D-printing with suitable polymer scaffolds and suitable ILs enables the design of membrane materials with precisely controlled sizes, shapes and geometries along with the necessary electrochemical performance. [3]

The aim of this work therefore is the synthesis and characterization of protic amine-based ILs for proton conduction. All compounds are ILs at room temperature. Their ionic conductivities range between 10-2 – 10-4 S/cm. Moreover, with wide electrochemical and thermal stability windows (ΔE up to 3 V, Tg around -90 °C and Td over 200 °C) these ILs are promising for ion transport in fuel cell membranes above 100 °C. The corresponding transparent and flexible IGs display promising thermal and mechanical stability and reach ionic conductivities of up to 10-3 S/cm at elevated temperatures. Moreover, this study also demonstrates that the IGs can be obtained and structured using 3D-printing; this clearly enables the design of many materials with different requirements by simply adapting the size and shape.

[1] A. Martinelli, A. Matic, P. Jacobsson, L. Börjesson, A. Fernicola, S. Panero, B. Scrosati, H. Ohno, J. Phys. Chem. B, 2007, 111, 12462.

[2] Y.-S. Ye, J. Rick, B.-J. Hwang, J. Mater. Chem. A, 2013, 1, 2719.

[3] K. Zehbe, A. Lange, A. Taubert, Sustainable Energy Fuels, submitted.
Synthesis and Analysis of Ionic Liquid As Additive for Li-Ion Battery Electrolyte
Authors: Cheng Chun
Published: May 2020

Lithium ion batteries are promising power sources for various applications such as portable electronics and electrical vehicles, due to their high specific energy density and long cycle life. As one key component of lithium ion battery, the electrolyte should allow lithium ion transport but prevent electron conduction. One big challenge of lithium ion battery is that the high voltage and high current in the charge process can cause self-decomposition of the electrolyte, leading to combustion of the battery. In order to solve the combustion problem in the fast charge process, new electrolyte materials with high ionic conductivity and good chemical stability are urgently needed.

Ionic liquid is usually organic salt consisting of anion and cation with low vapor pressure, high boiling point, high ionic conductivity, large specific heat capacity, and non-flammable characteristics. Ionic liquid is aqueous at or near the room temperature. The features of ionic liquid such as the high heat resistance and wide liquid temperature range make it a promising electrolyte material for lithium ion battery.

This project aims at tailoring the suitable structure of ionic liquid as the additive for lithium ion battery. Our ionic liquid is a designed composition of anion of TFSI as SEI forming additive and imidazole based cation. A two-step process has been developed for synthesizing ionic liquid. The physical and chemical properties of the ionic liquid were measured to evaluate the feasibility of applying ionic liquid to lithium ion battery.

Both the density and the viscosity of the ionic liquid are measured at different temperatures. The density was found to decrease linearly with temperature in both single and binary system. The determined negative excess molar volume of ethyl acetate and ionic liquid system is relative to the interaction between different molecules. The viscosity of the analyzed electrolyte solvent was found to decrease linearly with increasing temperature. Arrhenius-like law was found to be able to fit the measured data well. The fitting parameters were able to predict viscosity at different temperature.

The conductivity of the whole electrolyte system and compatibility with the active materials will be tested and discussed in the next study.
Investigation of Borohydride/Peroxide Desalination Cell in a Batch Regime
Authors: Hamilton Shawn Nicholas , Bassi Amarjeet , Karamanev Dimitri
Published: May 2020

Road salt has an environmental impact on the environment. According to one road salt monitoring organization, The Salt Institute, it is estimated that in North America alone, 6 million tonnes is dispersed annually. It has caused a negative influence on biotic life forms in freshwaters as well as the deterioration of infrastructure such as bridges and buildings through increased steel corrosion. In this work, a batch lab-scale electrochemical desalination cell (EDC) was studied to reduce the salt through utilizing the energy from NaBH4/H2O2 redox reaction. This 3-compartment borohydride/NaCl/peroxide cell was effective in desalinating different road salts: NaCl, CaCl2, MgCl2 and KCl. Combinations of different anion exchange membranes (AMI-7001; FAB-PPS-130) with different cation exchange membranes (CMI-7000; Nafion® 115; Nafion® 117) were studied. There were differences in desalination rate with varying pairings of membranes. Over 5 hours, the conductivity of a solution in batch regime has decreased by over 42%. The EDC’s maximum current and power densities were 5.32 A/m2 and 2.75 W/m2, respectively. These results have demonstrated the successful operation of an EDC using NaBH4 and H2O2 in batch regime.
Graphitic Carbon Nitride: An Excellent Base for Composite Electrodes in Electrochemical Energy Conversion and Storage
Authors: Ola Oluwafunmilola , Zhu Yanqiu
Published: May 2020

Growing environmental concerns linked with global energy demands have increased the need for sustainable, reliable and portable energy supply that can be delivered from energy conversion to energy storage. Although some emerging electrocatalysts can potentially compete with commercial electrocatalysts in terms of cost per unit kWh when using low-cost precursors to create them, research efforts are still mainly focusing on performance rather than cost. It is expected that flexible energy storage devices with multifunctionalities would spearhead the power management of future energy devices, which requires engineering solutions of volume and weight reduction. Nanocomposites that offer simultaneous energy conversion and storage capabilities with mechanical load bearing are promising candidates to provide these desired functionalities in electrochemical devices. Utilizing hierarchical porous polymers with combined properties of light weight, flexibility and absorption capacity offers numerous possibilities for the development and utilization of nanocomposites in applications ranging from electronics, aerospace, military to transportation where rapid or stored burst of energy is required for peak power, backup power and load levelling to achieve improved efficiency and reliability.

In this work, iron oxide nanoparticles encapsulated in graphitic carbon nitride shells (Fex-NC) were grown on interconnected, macroscopic carbon scaffold after dip coating followed by carbonization to attain multifunctional nanocomposites. The resulting composites based on the graphitic carbon nitride base possess combined properties of superb structural flexibility, high strength to weight ratio and mechanical stability. The Fex-NC nanocomposites were tested for energy conversion and storage, to take advantage of their porous graphitic carbon nitride features which would be beneficial for optimal ion transport to iron oxide nanoparticles. We have found that the resulting graphitic carbon nitride shells prevented direct contact between iron oxide nanoparticles and acidic electrolyte (H2SO4), so that improved efficiency, stability and corrosion resistance were achieved. They also exhibit excellent electrochemical performances with overpotentials of 191 mV to reach current density of 10 mA/cm2 for hydrogen evolution reaction. In addition to demonstrating excellent specific capacitance, these nanocomposites also possess good stability after 8 hours of testing. The results demonstrate that the physicochemical properties of multifunctional 3D foams developed from simultaneous carbonization and dip coating of polymeric templates can be used as an excellent base to host a variety of nanoparticles to create composite electrocatalysts and be further exploited for future energy and environmental technologies.
Superior Supercapacitor Based on the 3D Architecture of Multilayered Delta-MnO2 Nanosheets Grown on Carbon Nanoparticles
Authors: Walke Pravin S , Gupta Shobhnath
Published: May 2020

The two-dimensional nanostructures are attractive materials for energy storage electrode materials due to extensive intercalation of ions. The two dimensional layered structure with suitable van-der-Waals gap along with multilayered arrangement is favorable to enhance the intercalation of ions. We report an innovative architecture composed of two dimensional multilayer delta-MnO2 nanosheets grown on carbon nanoparticles (CNP) by simple, template-free, low temperature chemical method. The electrochemical kinematics investigation has been done through impedance spectroscopic analysis and scan rate dependent storage mechanism as effect of increasing temperature. The specific capacitance elevated to 321 F.g-1 as temperature improves upto 70oC at 2 mV.s-1 which is almost double increment in the capacitance and four times enhancement in the energy density. However, the stability is compromised only 25% up to 6000 cycles at 5 A.g-1 current density. The temperature increment is boosting ionic conductivity, enlarging the van-der-Waal gap and increasing charge transfer, simultaneously enrich intercalations of Na+ ions that initiate tremendous boost in energy storage. Thus a 3D architecture of multilayerd delta-MnO2 nanosheets exhibits high-temperature superior performance pseudocapacitors with low life spam by compensating which is highly noteworthy.