bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Oxygen Partial Pressure on the Fabrication and Characterization of LaB6-Doped-NiOx Thin Films Produced By Magnetron Sputtering
Authors: Wang Mengying , Diao Xungang 
Published: February 2020

Nickel oxide (NiOx) thin films doped with LaB6 were deposited and fabricated by direct current magnetron sputtering technique onto ITO glass substrates with various ratio of argon and oxygen. LaB6 target was just back the cathode and stacked on the nickel metal target on which six holes were drilled and punched to make the La3+ deposit on the substrate. The introduction and addition of La3+ are believed forming the defects, substituting the Ni2+ sites by the analysis of X-ray diffraction, scanning electron microscopy and atomic force microscopy. It obviously leads to the most roughness surface and large crystallite size of the thin films with the ratio of argon and oxygen at 45:5. Moreover, the electrochromic (EC) characteristics response for nonstoichiometric LaB6–doped-NiOx films show a strong dependence on crystallite size variations and surface morphology. Therefore, the as-deposited thin films above demonstrate the good optical contrast and excellent durability, especially the lifetime which can last more than 10000 s. The attempt of this work may be helpful for charactering the EC devices with doping NiOx thin films. We think it will be a big step for the smart windows in energy efficient buildings.

Key words: LaB6–doped-NiOx films, optical contrast, electrochromic (EC) characteristics

Figure 1
Multi-Color Electrochromism in Vanadium Oxide Thin Films
Authors: Song Giljoo , Mjejri Issam , Gaudon Manuel , Rougier Aline 
Published: February 2020

Abstract
To date, numerous researchers have spent great efforts in searching for transition metal oxides with diverse properties. Vanadium oxide are a family of interesting materials with high catalytic, electrical, optical and magnetic properties and potential applications such as thermochromic smart windows, batteries and electrochromic devices[1-2]. In this study, vanadium oxide thin films were deposited by two techniques, namely, reactive RF magnetron sputtering and Doctor Blade leading to V2O5 films with a wide range of optical properties. RF sputtered films deposited in gas mixture of argon and oxygen at room temperature on ITO substrates crystallized in an orthorhombic structure when using a V metal target while they were amorphous from V2O5 target. Depending on the deposition conditions, the film morphology was layer or needle type. Orthorhombic V2O5 thin fims were prepared by Doctor Blade deposition on ITO substrate from V2O5 powder synthesized by polyol process[3-4]. Independently of the deposition technique, the electrochromic properties of vanadium oxide films showed multi steps electrochromism, namely yellow to green, green to blue, and blue to grey, in lithium based electrolyte. The optical transmittance characterized by UV-visible spectrophotometer showed a maximum difference of 40% at 550 nm for RF sputtered films while a contrast in reflectance of 20%, in the spectral region 550-700nm, was recorded for Doctor Blade films. The influence of lithium insertion/desinsertion in the structure and chemical state was investigated using GIXD and XPS analysis. The relationship between the film structure, morphology, thickness, correlated with their deposition conditions and the EC mechanism will be discussed. References

Cao Z and Wei B, V2O5/single-walled carbon nanotube hybrid mesoporous films as cathodes with high-rate capacities for recharge able lithium ion batteries, Nano Energy 2, 481 (2013).

Yaoming Sun et al., Anisotropic vanadium dioxide sculptured thin films with superior thermochromic properties, Scientific Reports, 3, 2756 (2013).

I. Mjejri, L. Manceriu, M. Gaudon, A. Rougier, F. Sediri, Solid State Ionics, 292 8-14 (2016).

I. Mjejri, A; Rougier, M. Gaudon, Inorganic Chemistry, Submitted.
Structure-Dependent Response Characteristics of Electrochromic Dye-Modified Transparent Conductive Oxide Porous Electrode
Authors: Watanabe Yuichi , Suemori Kouji , Kamata Toshihide 
Published: February 2020

Fast-response electrochromic (EC) cell composed of EC dye-modified TiO2-nanoparticle-based transparent porous electrode was reported by R. Cinnsealach et al. (Sol. Energy Mater. Sol. Cells, 55, 215, 1998). From then, TiO2 porous electrodes modified with EC dyes have been regarded as a promising candidate for fast-response EC display (ECD) applications. Our research purpose is the realization of flexible fast-response ECD applications. However, TiO2 porous electrodes require high sintering temperature (>400 °C) to use as EC electrode because TiO2 has high resistivity. This high process temperature required by TiO2 porous electrode was an important obstacle for their application as transparent electrodes in plastic substrate-based flexible ECDs. To solve this problem, we substituted transparent conductive oxides (TCO) for TiO2 as the porous electrode material. TCO materials have high electrical conductivity than TiO2, so they have the potential to work as the EC electrode even if they are sintered at low temperature.
Previously, we reported that the porous electrodes consisting of indium tin oxide (ITO) nanoparticles exhibit good optical transparency and high electric conductivity. Moreover, EC response characteristics of EC-dye modified ITO porous electrode sintered at 150 °C was improved than that of conventional TiO2 porous electrode due to its high conductivity (AIP Adv., 6, 065121, 2016). Therefore, TCO porous electrodes have potential for application in porous electrode for flexible ultrafast-response ECDs. To achieve such applications, it is necessary to analyze the factors controlling the EC response speed in TCO porous electrodes.
In this study, we investigated the response characteristics of EC dye-modified ITO, antimony-doped tin oxide (ATO), and TiO2 porous electrodes. ITO and ATO porous films have low electric resistivity due to their high electric conductivity. As mentioned above, ITO porous electrode exhibited fast response. On the other hand, low-resistivity ATO porous electrode exhibited slower response than that of a conventional high-resistivity TiO2 porous electrode. This clearly indicates that the EC response speed of the ATO porous electrode is dependent on a factor other than the electric resistance of the porous film. From the structural comparisons, it is revealed that the pore size of the film consisting of small nanoparticles is one of the key factors controlling the EC response speed of porous electrode. The details about the effect of porous film structure on EC response characteristics will be discussed.
Portable High Surface Area TiO2 Nanotube Array Sensor for the Detection of Benzene at Room Temperature
Authors: Hegde Shruti , Mohanty Swomitra , Kelly Kerry E. 
Published: February 2020

Benzene is one of the few known human carcinogens as identified by the International Agency for Research on Cancer. It is a common indoor and outdoor pollutant, with sources ranging from cigarette smoke to traffic. Hence, there is an increasing need to detect low concentrations of benzene. Metal-oxide based nano-sensors, with their simple sensing mechanisms make for a good choice. Thin films based on titanium dioxide (TiO2) have previously been shown to respond to benzene (1), however these sensors are run at high temperatures (160-200°C), require a complex setup for operation, and have low surface area for sensing. This paper presents the development of TiO2 nanotube based sensor array (Figure 1) that has high surface area, is highly sensitive, and operates at room temperature using portable and simple instrumentation. TiO2 nanotubes were synthesized through anodization in electrolytic solution of ammonium fluoride (NH4F)-ethylene glycol (EG) and oxygen annealed for up to 500°C. The response of the synthesized hollow nanotubes was studied at room temperature for different concentrations of benzene vapor (100-500ppm). The response of the sensor coupons to benzene vapor was measured using an amperometric technique. The results showed an increase in current that was directly proportional to the concentration of benzene in the sample which indicates a quantitative nature of the sensor (Figure 2). The sensor was placed in a portable system which can be deployed to potential contamination sites for real-time monitoring applications. Results on sensing mechanism, stability of the sensor over time, sensor reusability, and detection limit will be presented.
(1) Mabrook M., Hawkins P. (2001) Sensors and Actuators, B: Chemical
75, 197-202.

Figure 1
Movement Intention Prediction By Superficial Magnetic and Pressure Sensor
Authors: Plaza Mauricio , Cifuentes Mauricio 
Published: February 2020

This paper presents a discussion about the implementation of superficial magnetic sensor and pressure sensor to find patterns and parameters in order to predicting the intention of movement for people with musculoskeletal system problem in lower limbs.
The information is obtained through reading position and movement by magnetic and pressure sensor installed in different parts of the body. The advantage of this sensor is the reference of the position of the every part of the body. Using the sensor in some parts of the body is possible to calculate the muscle contraction for the prediction of intended movement.
Conducting Molecularly Imprinted Polymer (MIP) Chemical Sensors for Toxic N-Nitrosamines Selective Determination in Heat Processed Food of Animal Origin
Authors: Kutner Wlodzimierz , Garcia-Cruz Alvaro , Lach Patrycja , Sharma Piyush Sindhu , Pieta Piotr , Golebiewska Karolina K. , Cieplak Maciej , Noworyta Krzysztof R. , Schulz Emmanuelle , D'Souza Francis 
Published: February 2020

High-temperature processing of meat food generates in it toxic heteroaromatic amines and nitrosamines (NAs)1,2 causing chronic diseases including hormonal dysfunctions and cancer.3 Therefore, we devised and fabricated chemical sensors for selective determination of the N-nitroso-L-proline (Pro-NO)4 and N-nitroso-thiazolidine-4-carboxylic acid (NT4A) toxins in this food. We applied films of conducting polymers molecularly imprinted (MIPs) with either the Pro-NO or NT4A template as recognition units of these chemosensors. For selection of most appropriate functional monomers, we used DFT at the B3LYP/3-21G(*) level modeling to find phenolic derivative of bis(bithiophene) and a thiosalenCo(III) complex (CS)5,6 suitable to form pre-polymerization complexes with Pro-NO and NT4A, respectively, at the 1:2 template/monomer stoichiometry. The calculated Gibbs free energy gain due to formation of these complexes with a series of NAs was proportional to the UV-vis spectroscopy determined stability constants of these complexes. These constants were relatively high equalling 3.14×109 M-2 and 2.72×1010 M-2for Pro-NO and NT4A, respectively. Then, we electrochemically polymerized these complexes under potentiodynamic conditions. This electropolymerization resulted in depositing thin MIP films on different electrode substrates. After subsequent extraction of the Pro-NO and NT4A templates from MIPs, we used the resulting MIPs with empty imprinted cavities for determination of Pro-NO and NT4A analytes in grilled pork neck samples. We confirmed the presence and then absence of NA templates in the MIP films before and after extraction, respectively, with FTIR spectroscopy and XPS, and then characterized morphology of the films with AFM. For analytical signal transduction, we used piezoelectric microgravimetry (PM) at the Au-QCR/MIP electrodes of EQCM as well as DPV and EIS at the Pt/MIP electrodes. Limits of detection of the chemosensors were 36.9 nM Pro-NO (with EIS) and 46 nM NT4A (with DPV). The chemosensors selectively responded to the target toxins in the presence of interfering compounds of similar composition and structure. Successful selective determination of Pro-NO and NT4A in the food extract samples indicates that the chemosensors are promising as tools for determination of these toxins in food of animal origin.

References

1. Santarelli R. L. et al., Nutr. Cancer
2008, 60, 131.
2. Oostindjer, M. et al., Meat Sci.
2014, 97, 583.
3. Larsson S. C. et al., Int. J. Cancer
2006, 119, 915.
4. Lach P. et al., Chem. Eur. J.(2016) in press, DOI:10.1002/chem.201604799.
5. Pan, M.; et al., Biosens. Bioelectron.
2012, 31, 11.
6. Zhao, L.; et al., Sens. Actuators, B Chem.
2012, 171–172, 563.

Figure 1
Development of WO3 Nanoparticle Based pH Sensor
Authors: Jamal Mamun , Akhter Irani , Shao Han , Yousuf Mohammad A. , Razeeb Kafil M. 
Published: February 2020

In biological and environmental applications, pH is an important parameter that needs to be monitored at a regular basis. Conventionally, the measurement process takes a considerable amount of time involving several calibration steps and handling of fragile electrodes. In this work, we propose a new, robust and reliable way of sensing pH. The sensor has been fabricated based on tungsten oxide nanoparticle modified glassy carbon electrode (WO3/GCE) (Fig. 1). WO3 is a promising material for pH sensor because of its availability, stability, good morphological and structural control of the synthesized nanostructures, reversible change of conductivity, high sensitivity, selectivity and biocompatibility.1 Furthermore, WO3 is a well-studied wide band gap semiconductor (~2.75 eV) used for several applications as chromogenic material and catalyst.2

In this work, hydrothermal synthesis method was used for the fabrication of WO3 nanoparticles. For the fabrication of the pH sensor, the nanoparticles were mixed with Nafion and chitosan before drop coating onto the GCE surface. Scanning electron microscopy (SEM), x-ray diffraction (XRD), transmission electron microscopy (TEM) was used to characterize the nanoparticles. Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used to monitor the potential shift based on different pH in the buffer solution. The WO3/GCE pH sensor showed a sensitivity of 1.15 VpH-1cm-2 at 25 °C and a potential drift of less than 5% after three hours of continuous use. The sensor showed good linearity at a pH range of 3 -10 and could retain 95% of its initial sensitivity after 1 week of use. The good sensitivity and long term stability of this WO3 based sensor may allow the development of a low cost pH sensor for a wider range of applications.3

Acknowledgement

This work is financially supported by Science Foundation Ireland funded project “SweatSens” under the grant agreement No. 14/TIDA/2455 and the University Grant Commission (research support and publication division), Bangladesh.

Corresponding authors' email addresses: mamun.jamal@chem.kuet.ac.bd and kafil.mahmood@tyndall.ie

Reference

1. D. Vernardou, H. Drosos, E. Spanakis, E. Koudoumas, C. Savvakis, N. Katsarakis, J. Mater. Chem., 2011, 21, 513.
2. M. Natan, T. E. Mallouk, M. S. Wrighton, J. Phys. Chem. 1987, 91, 648.
3. L. Devlin, M. Jamal and K. M. Razeeb, Anal. Meth. 2013, 5, 880.
Figure 1. Schematic diagram of WO3 nanoparticle based pH sensor.

Figure 1
Paper Microfluidic Electrochemical Sensor for Salivary Cortisol Analysis
Authors: Fernandez Renny Edwin , Manickam Pandiaraj , Bhansali Shekhar 
Published: February 2020

Cortisol is an accurate biomarker of stress; found abundantly in serum and saliva. Continuous monitoring of cortisol over a span of 24 hours can yield important information on a person’s stress level and endurance. The current gold standards of cortisol analysis are lab centric and not point of care. We present a paper-microfluidic electrochemical sensor specifically designed for cortisol detection from saliva samples.
Graphene electrodes were screen printed on paper along with a layer of Zinc Oxide- metalloporphyrin for enhanced electrochemical detection. The proposed cortisol sensor is based on a competitive binding assay, conducted in a paper reaction site. Response of the sensor was found to a strong linear function of cortisol concentrations in the 50 pM-100 nM range. Limit of detection was found to be as low as 10 pM. The proposed sensing technique was used to detect cortisol levels in clinical saliva samples. In comparison to existing techniques for cortisol detection, our method does not rely on immobilized affinity probes. Rather a magnetic bead based approach has been adopted to deliver the samples to the electrochemical site

Figure 1
Cu-Sb Alloys As Electrode Materials for Lithium Ion Batteries; Thermodynamics, Electrochemistry and Structural Aspects
Authors: Beutl Alexander , Flandorfer Hans , Effenberger Herta Silvia 
Published: February 2020

Cu-Sb alloys have recently gained much attention as promising electrode materials for lithium ion batteries. Sb, as the active agent, has a theoretical capacity of 660 mAhg-1, forming Li3Sb in the fully lithiated state. Cu on the other hand does not react with lithium and can precipitate upon lithiation of Cu-Sb alloys. The Cu matrix is mandatory, as the change in volume between pure Sb and Li3Sb is about 200% and therefore the structural integrity of the electrode material is compromised by the mechanical stress built up upon cycling of the cell.
Although much information is already available on the cycling performance of Cu-Sb electrodes, almost no data on the thermodynamics behavior exists. This is surprising as many thermodynamic parameters have a direct correlation to the electrochemical performance as well as kinetics of a material system. Therefore an extensive experimental investigation was conducted in the system Cu-Li-Sb, applying thermochemical as well as electrochemical methods.
Our investigations started with the development of fundamental property diagrams like isothermal sections and isopleths in the system Cu-Li-Sb. Thereby yet unknown ternary compounds were found and structurally characterized. On the basis of this data, reaction paths for the lithiation of different Cu-Sb alloys were proposed and further validated by electrochemical investigations, i.e. coulometric titrations. Reasons for the good cyclability of Cu-Sb alloys were found to be deeply rooted in the structural relations of the ternary compounds formed upon lithiation and their corresponding binary counterparts β-Cu3Sb and Li3Sb.
This work has been funded by the DFG under project FL-730/1-2 within the priority program SPP 1473 “WeNDeLIB”.
Cycling Performance of Lithium Iron Sulphate in the Presence of Binders and Carbon Additives
Authors: Muthiah Aravind , Copley Mark , Srinivasan Madhavi 
Published: February 2020

Fe-based high voltage positive electrode material Li2Fe(SO4)2 has shown consistent cycling only in experimental Swagelok cell configurations.[1, 2] In order for it to be practically viable, knowledge of its interaction with commercially used additives in the coating process is lacking. Thus, this work seeks to study the cycling performance of Li2Fe(SO4)2in a half cell configuration with different types of binders and carbon based additives as a step towards commercial utilisation of the material.
Flourinated binder polvinylidene fluoride (PVDF) and non-fluorinated binder polyacrylonitrile (PAN) were both evaluated and shown to perform similarly. The long term cycling at low C-rates was found to be consistent for the systems with and without binder. However, at high C-rates a significant fall in capacity of nearly 60% was observed for the system with binders in comparison to the system without binder.
Li2Fe(SO4)2 being polyanionic has poor electronic conductivity and requires carbon coating to enhance performance. This study investigates the effects of amorphous Super-P Carbon, Multi Walled Carbon Nanotubes and Single Walled Carbon Nanotubes when ball-milled with the electrode material. The carbon-coated material was then subjected to galvanostatic charge discharge tests over multiple cycles and at different charging rates. This study on the effect of binders and carbon additives lays the foundation for future work on an all-iron lithium battery and is a step forward in commercialising sulphate based cathode materials.
[1] M. Reynaud, M. Ati, B. C. Melot, M. T. Sougrati, G. Rousse, J.-N. Chotard, et al., "Li2Fe(SO4)2 as a 3.83 V positive electrode material," Electrochemistry Communications, vol. 21, pp. 77-80, 2012.
[2] L. Lander, M. Reynaud, G. Rousse, M. T. Sougrati, C. Laberty-Robert, R. J. Messinger, et al., "Synthesis and electrochemical performance of the orthorhombic Li2Fe (SO4) 2 polymorph for Li-ion batteries," Chemistry of Materials, vol. 26, pp. 4178-4189, 2014.

Figure 1
Electrochemical Mechanism of Room Temperature Sodium/Sulfur Battery with Tegdme Electrolyte
Authors: Kim Icpyo , Kim Changhyeon , Kim Hui-Hun , Kim Ki-Won , Ahn Jou-Hyeon , Ahn Hyo-Jun 
Published: February 2020

The high temperature Na/S battery working above 300°C has been highlighted as a promising candidate for large scale energy storage systems. It carries many advantages such as low-cost raw materials, high energy density (760 Wh kg-1), high coulombic efficiency, and a long cycle life. However, it suffers from critical problems of the safety issue, etc. For example, sulfur and sodium polysulfides are in the liquid state and react with sodium vigorously. In the case of a failure of solid electrolyte separator (β"-Al2O3), a fire or an explosion can take place.
The room temperature Na/S battery with tetraethylene glycol dimethyl ether (TEGDME) electrolyte (hereafter referred to as the Na/S battery) can overcome these drawbacks. Furthermore, assuming Na2S as the final discharge product, sulfur cathode has a high theoretical specific capacity of 1672 mAh g-
1 and the Na/S battery has a high theoretical energy density of 1230 Wh kg-1.
Sulfur in the Na/S cell has been reported to involve complicated transition processes during charge/discharge. It evolves from S8 to Na2S through various sodium polysulfides such as Na2S6, Na2S5, Na2S4, Na2S3 and Na2S2 during the discharge and does reversely during charge. Especially, the high-order polysulfides (Na2Sn, 4 ≤ n ≤ 8) are generally believed to dissolve into the TEGDME electrolyte, bringing a number of drawbacks such as low discharge capacity, fast capacity decay during cycling and deterioration of the sodium anode due to the shuttle effect. Thus, some strategies such as a solid electrolyte separator (β"-Al2O3), ion selective polymer membranes, and interlayers have been applied to suppress the shuttle effect of the high-order polysulfides (Na2Sn, 4 ≤ n ≤ 8). Inversely, there have also been several studies such as catholyte system to use their soluble properties. The low-order ones (Na2Sn, 1 ≤ n ≤ 3) are considered to generally be in the solid state and contribute to the low discharge capacity and high polarization due to the low electronic and ionic conductivities. These mean that understanding the evolution of sulfur in the cathode to sodium polysulfides (Na2Sn, 1 ≤ n ≤ 8), based on solubility, is critical for understanding and developing the Na/S battery. However, previous studies have focused only on identifying the chemical species of sodium polysulfides (Na2Sn, 1 ≤ n ≤ 8), which were even partially identified, and there has been no study on the Na/S battery in viewpoint of the solubilities of sodium polysulfides (Na2Sn, 1 ≤ n ≤ 8).
In the present study, we aim to investigate the formation and variation of sodium polysulfides during charge/discharge. Sulfur cathode and sodium anode are examined at different points of the charge/discharge by separating both electrodes with the beta alumina solid electrolyte separator (β"-Al2O3). The solubilities of sodium polysulfides of Na2Sn (1 ≤ n ≤ 8) are measured and compared to the sulfur cathode visually.