bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thin Layer Disposable Flow Cells As (Spectro)Electrochemical Detectors in FIA Systems
Authors: Fanjul Bolado Pablo , Kanso Hussein , González García María Begoña , Hernández Santos David 
Published: February 2020

In this work different flow-cell electrochemical platforms where channel slide is directly mounted over the screen-printed electrodes are proposed. Flow-cells for screen-printed electrodes are usually wall-jet type but due to the transparent cover that defines the channel (height 400μm, and 100μL of volume), a thin layer is formed over the electrochemical cell. The cover’s transparency allows the detection of air bubbles inside the cell. The injection is done through an “in-line luer injection port” where sample volume can be easily controlled by operator through a Hamilton syringe.
Different configurations of the electrodes in the electrochemical platform can be used, rectangular or circle electrodes, only a working electrode or dual sensors as well as different materials such gold, platinum or carbon, etc.
These electrochemical flow cells combining with the adequate holder and fittings allow us to have an user friendly FIA system with a great possibility of applications based on electrochemical or spectroelectrochemical detection, depending on the set-up used to carry out the measurement.
Here in several samples of the use of these thin layer electrochemical flow-cells as transducers of enzymatic sensors or as detectors are presented showing a good performance, simple operability and effectiveness of working in FIA systems.
The work was carried out in the framework of the European project “BIOENERGY”. This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 607793”.
A Printed Capacitor with Carbon Nanotube Electrodes for Energy Storage
Authors: da Costa Tallis H. , Choi Jin-Woo 
Published: February 2020

Capacitor-type energy storage is becoming an attractive option as it can be fabricated with simple methods and allows integration into a flexible substrate for wearable applications. Currently, there is a need for reliable and simple fabrication methods that take into account the characteristics of nanomaterials for their controlled deposition. Inkjet printing presents advantageous features because it allows solution-processed materials to be printed with high accuracy and resolution. Therefore, a number of patterning steps can be performed sequentially, thus minimizing the need for lithography or other fabrication methods. We have fabricated a fully inkjet-printed capacitor as energy storage for wearable sensors.
We have explored several configurations of capacitors. A parallel plate capacitor is composed of carbon nanotubes that are inkjet printed on PET film to form a compact conductive mat structure. The assembly is composed of two layers of carbon nanotubes separated by a dielectric layer of polymer, as illustrated in the figure (left). The advantage of this design is that it does not require an electrolyte to function and can be printed on flexible substrate such as PDMS. On the other hand, a supercapacitor configuration achieves higher energy storage, power density, and is also of simple construction [1]. The supercapacitor type is constructed by printing carbon nanotubes and subsequently by electrodepositing a metal oxide. It is finally assembled with a separator membrane for ion conduction and filled with electrolyte, as shown in the figure (right). The charge storage based on the redox reactions of the metal oxide is mainly responsible for its capacitance [2]. The energy storage and power density of the supercapacitor are greatly improved with the use of carbon nanotube electrodes, because of the high surface area of carbon nanotubes.
We demonstrate the capacitor as a charge storage component that is integrated in a wearable system. Moreover, our inkjet printing system precisely prints a network of carbon nanotubes. We show that the inkjet-printed capacitors provide a rapid and reliable fabrication for wearable systems.
References
[1] M. Zhi, C. Xiang, J. Li, M. Li, and N. Wu, Nanoscale, 5, 72–88 (2013).
[2] X. Zhang et al., ACS Nano, 5, 2013–2019 (2011).

Figure 1
Cyclic Voltammogram of Paclitaxel Nanoparticles
Authors: Miller Steven T , Lee Dongwon , Prabhulkar Shradha , Williams Gary W , Trieu Vuong N 
Published: February 2020

Background: Successful nanoparticles formulations include Abraxane® (an albumin bound nanoparticle paclitaxel), Genexol-PM® (a polymer bound nanoparticle paclitaxel), and Doxil®. At LipoMedics we have developed a unique nanomedicinization process of water insoluble drug for intravenous administration using combination of solvents and polymers. The polymers can be simple phospholipid or synthetic diblock polymer or complex protein such as albumin. Electrochemistry was used to understand the molecular organization of these nanoparticles and biosensor built to support the in process monitoring of this pharmaceutic.

Materials and Methods: Nanoparticle synthesis was conducted using a two step method whereby the drug is first emulsified in presence of solvent and then nanofabricated in presence of polymer. Nanoparticle size and zeta potential were measured using a Malvern ZS DLS system. The formulation was subjected to serial filtration using 1.2µm, 0.8µm, 0.45µm and 0.2µm syringe filters. The drug incorporation/loading was measured using ELISA. Electrochemical properties of the formulation were measured using screen printed carbon nanotube (CNT) electrodes from DropSens and a PGSTAT204 Autolab Potentiostat from Metrohm. The drug being evaluated in this study is paclitaxel- a water insoluble drug that can only be solubilized in Cremophor EL for intravenous administration. Only nanomedicinization allowed paclitaxel to be formulated without solvent.

Results:A series of stable nanomedicinized paclitaxel formulations were created using chloroform or ethanol as solvent and phospholipid or albumin as polymer. Each formulation exhibited a distinct cyclic voltammetry (CV) scan. The CV scan was highly dependent on the polymer used. Monolayer and bilayer phospholipids behaved similarly as polymer with or without paclitaxel. Increasing the loading of these phospholipid nanoparticles caused a shift from profiles of high capacitance material to profiles of low capacitance material.

Discussion: Capacitance of a carbon-based electrode consists of two major components: the electrical double layer capacitance due to the electrostatic attraction of charged carbon surfaces to electrolyte ions and the pseudocapacitance due to the Faradic reactions of electroactive species on the carbon surfaces. During electrochemical evaluations, the nanoparticles were treated as ionic liquid capacitance material. Low capacitance is suggestive of weakened charge accumulation in the electrode - electrolyte interface which depends on the mesoporosity and electrolyte accessibility of the capacitive material.
Optical Characterization of CaCu3Ti4O12 thin Films
Authors: Skaria Giji , Sundaram Kalpathy B 
Published: February 2020

CaCu3Ti4O12 is in the family of perovskite materials that may have potential electrical as well as optical applications. In this study, we have focused on the optical properties of the films. These films are deposited by RF magnetron sputtering process using CaCu3Ti4O12target. The films are deposited under varies deposition conditions that include argon gas flow ratios, process pressures and substrate temperature. The transmission and reflection properties are performed using the UV-Visible spectrophotometer to extract the bandgap and refractive index of these films.
Interaction of Thiol Ligands with Gold in Electrocatalytic CO2 Reduction
Authors: Cheng Xun , Fang Yuxin , Xu Ye , Flake John 
Published: February 2020

The electrocatalytic CO2 reduction reaction (CO2RR) has the potential to produce fuels and chemicals from a renewable feedstock: It can be used as an energy carrier to store energy generated from intermittent, distributed sources such as wind and the sun. It can also be used as a renewable source of carbon for chemical production. The key to enabling these uses of CO2 is to maximize the selectivity and energy efficiency of electrocatatlytic CO2RR toward the desired product. We have taken inspiration from biological enzymes that catalyze CO2RR (e.g. carbon monoxide dehydrogenase) and attempt to mimic their active sites by functionalizing Au electrodes with a series of organic thiol ligands, to seek opportunities to potentially break the constraints imposed by scaling relations. Our work shows that different thiol species can enhance the activity for the formation of different CO2 reduction products. For instance, 2-merceptanpropionic acid effectively reduces the yield of CO to negligible amounts and enhances H2 evolution to nearly 100% faradaic efficiency. 2-phenylethanethiol, on the other hand, strongly promotes CO evolution and suppresses H2 evolution, whereas 4-pyridinylethanemercaptan boosts the faradaic efficiency toward formate by suppressing CO formation.
We have performed detailed density functional theory calculations and theoretical modeling in conjunction with our electrochemical experiments to elucidate the role of the thiol ligands in CO2RR on Au. We find that thiol ligands exist primarily as thiolates on Au in the potential range relevant to CO2RR. They can readily reconstruct Au surfaces at ambient conditions, leading to a higher proportion of under-coordinated sites where the activity of CO2 reduction is significantly promoted but the effect of under-coordinated Au sites on H2 evolution is less prominent. In addition, different functional groups on thiols create different local reaction environments on the Au electrode resulting in different product speciation. Spectroscopic evidence for thiol and non-thiol ligands adsorbed on Au will also be discussed; for instance, S-binding and C-binding ligands exhibit distinct vibrational signatures with different electrochemical stabilities. Overall our study suggests that functionalization of Au holds significant promise for promoting CO2 reduction and achieving different product selectivity with appropriately chosen thiol-based ligands.
Optical Reflectance Spectroscopy of Spin-Coated Multilayered ZnO and Al:ZnO Thin Films
Authors: Buckley Darragh , McCormack Robert , McNulty David , Zubialevich V.Z. , Parbrook Peter J. , O'Dwyer Colm 
Published: February 2020

Transparent conducting oxides are unique in their ability to be incorporated into a variety of electronic devices such as LCDs, photovoltaic cells and LEDs. This unique ability is due to the oxides having wide band gaps (Eg
~ 3 eV - 4 eV) which gives high transparency (> 80% in visible region) and effective conductivity (>103 Ω-1cm-1) which can be achieved through the introduction of dopants. Zinc oxide is a well-known material of interest due to its wide band gap (Eg
~ 3.3 eV at 300 K) and also for the variety of methods by which it can be processed. Moreover, ZnO is readily able to alloy with other metals in the oxide form and has a lattice that can facilitate interstitial doping. This gives ZnO a key role in the area of optoelectronics, metal oxide thin films and thin film transistor (TFT) technologies.
We show the visible and near-infra red (VIS-NIR) light spectroscopy of ZnO and Al:ZnO multi-layered thin film structures grown on oxidized silicon substrates. Using optical interference, the thickness of the multi-layered deposited ZnO and Al:ZnO can be determined. Using angle-based reflectance spectroscopy measurements and a method derived from reflectivity of dispersive, non-absorbing materials, the optical thickness of thin films samples are calculated. These calculations show an excellent agreement with the actual thickness of ZnO samples with a margin of error of <4% for a 20 layer (500 nm thick) film and <1% for a single-layer ZnO film. This work also investigates the anti-reflection properties of ZnO and Al:ZnO thin films at a variety of angles of incidence. Results show that film’s minimum reflectivity (< 8%) can be tuned in the visible frequency range, based on number of iterative layer depositions and subsequent thickness.
Formation and Evaluation of Cyanide from Cyanide Free Solution By Electroplating
Authors: Kitago Takuya , Tamaki Kazuma , Mizuhashi Shoei , Koiwa Ichiro 
Published: February 2020

In recent years, environmental problems are regarded as important in all industries. Especially in the plating industry, cyanide, which is a toxic substance is strictly regulated, plating bath with cyanide and plating bath without cyanide are strictly distinguished. This is carried out on the premise that cyanide is not generated from a plating bath without cyanide. As such cyanide compounds are severely regulated, there are adverse effects such as cyanide spill accidents, waste water treatment must be done, so stop using cyanide compounds and use raw materials and manufacturing methods not containing cyanide compounds it tends to be. However, when defected samples plated from bath without cyanide was analyzed by using thermal desorption spectrometry (TDS), The bath with synthesized cyanide was removed by activated carbon treatment, but it was confirmed that cyanide was formed even in a plating bath without cyanide. The case where cyanide was detected from a cyanide-free plating bath was also reported in the 1980's,1) it had reported that it was possible to synthesize cyanide when carbon source and nitrogen source were present and conditions were set there.2) It was also reported amines and nitrite ion reacted and formed cyanide.3) We have reported that the cyanide was synthesized in the solution containing glycine.4) All plating baths were adjusted to 0.2 mol/dm3. Bath pH was adjusted at 12.0. Plating conditions were as follows, anode was nickel, cathode was platinum, a current density was controlled from 10 A/dm2 bath temperature was 60 °C. A electrolysis time was controlled from 60 min. Cyanide concentration was determined by the pack test and the picric acid method. The pack test is used to determine the presence or absence of cyanide. The picric acid method was used to determine cyanide concentration in the bath. Figure 1 showed effect of chemicals, amine and amino acid, on amount of synthesized cyanide. However, the amount of cyanide produced by amines was as low as 0.1 ppm for N-methylethylene-diamine (N-MEDA) and 4.7 ppm for N-ethyl ethylene-diamine (N-EEDA). Among the amino acids, without glycine the maximum of β-alanine was about 6.6 ppm, and the minimum was less than 0.1ppm. However, when a glycine bath was used, cyanide of 50.9 ppm could be measured. Glycine bath was found to be easy to produce cyanide.
1) M.Nonomura, Jitsumu Hyomen Gijyutsu, 32(1), pp11-20 (1985) [in Japanese]
2) M.Hara and T.Ishikawa, Mizusyorigijyutsu, 22(3), pp215-218 (1981) [in Japanese]
3) T.Koshimizu, K.Takamatsu, M.Kaneko, S.Fukui and S.Kanno, HyGienic Chemistry, 21(6), pp326-329 (1975) [in Japanese]
4) S.Mizuhashi, T.Arakawa, N.Watanabe, S.Koike, M.Urano, K.Maejima, N.Hirashita and I.Koiwa, Electrochemistry, 84(6), pp394-397 (2016) [in Japanese]

Figure 1
Electrochemical and Structural Investigation of Metal-Electrodes for an Energy-Efficient CO2-Reduction Process
Authors: Bienen Fabian , Wagner Norbert , Friedrich K. Andreas , Kopljar Dennis , Löwe Armin , Klemm Elias 
Published: February 2020

Sustainable conversion of CO2 to formic acid by an electrochemical process, often called ‘artificial photosynthesis’ due to the O2 produced at the counter electrode, can help to reduce the CO2 emission from industrial production sites. The produced formic acid can be used for a wide variety of applications in the pharmaceutical and chemical industry or it can be stored and converted back to electrical energy via a fuel-cell like device. Thus, this process can help to stabilize the power-grid during peak-times by providing control power. The basic idea of this process is the well-known concept of power to chemicals to store energy and additionally reduce CO2 emissions.
By using carbon supported Sn/SnOx gas diffusion electrodes (GDE), an efficient electrochemical conversion of CO2 to formic acid can be realized. The porous structure of the GDEs strongly affects the electrochemical performance of these GDEs. In detail, the intrusion of the electrolyte and CO2 into the electrode has a considerable influence onto the cathodes physicochemical characteristics. The intrusion behaviour of the electrolyte was investigated to determine the inner hydrophobicity, by using a combination of the Lucas-Washburn and Owens-Wendt method. To further investigate the penetration behaviour a custom-made cell was used to measure the capillary pressure.
Additionally iridium oxide based electrodes are used as anodes for the oxygen evolution reaction (OER) and optimized regarding their electrochemical performance. With these anodes and the above mentioned GDEs a continuous working full-cell set-up can be realized. The full-cell set-up was investigated by polarisation- and electrochemical impedance spectroscopy-measurements.
Electrical Characteristics Improvement of NAND Flash Memory on Experiment to Replace 49BF2+ with 11B+ in Implantation of Ions
Authors: Choi Hyun-Mook , Roh Yonghan 
Published: February 2020

As device size of NAND Flash is shrinking, the program and erase operations need the smaller number of electrons. So the importance of decreasing electron loss is getting increase. Because electron loss causes degradation of the device reliability. As has been discussed before, ion-implantation damage is important factor of NAND Flash fabrication process and device characteristics. Ion implantation damage makes interface trap so it causes electron loss in the device. The heavy ion mass (amu) ion-implantation process makes inevitably not only severe surface lattice damage and more defects in silicon (Si) surface but more thermal budget to recrystallizing. After RTA (Rapid Thermal Annealing) process, the unrestored defects exist at the silicon (Si) surface by heavy ion mass (amu) ion-implantation process damage. In this paper, we focus on endurance improvement characteristics between 49BF2+ ion implantation and 11B+ ion-implantation in 1X floating-gate (FG) NAND Flash cell. The interface trap density (Dit) decreases during initial and stress status by replacing 49BF2+ with 11B+. and erase Vth shift improves after 50k program/erase cycles. From experimental results, we found that the improvement by replacing 49BF2+ with 11B+ reduces interface trap at Si/SiO2 and improves endurance by reducing erase Vth shift in the program/erase cycles.
The Effect of Polypyrrole in the Capacity Retention of Fe3O4/Polypyrrole Composite Electrodes in Lithium-Ion Batteries
Authors: Bruck Andrea , Gannett Cara N , Bock David C , Smith Paul F , Marschilok Amy C , Takeuchi Esther S , Takeuchi Kenneth J 
Published: February 2020

Future device applications will dictate increases in the energy density of batteries, which may be accomplished by incorporating high capacity electroactive materials into composite electrodes where all the electroactive material is electrochemically accessible and the mass and volume contributions of passive components are minimized. Electroactive materials are incorporated into batteries through the fabrication of composite electrodes, where several additives may be used to enhance conductivity and to mechanically bind the components. Typically, an electrically conductive carbon additive (e.g. acetylene black or graphite) and a polymer binder (e.g. PVDF and PTFE) are mixed with the electroactive material to form a composite electrode. Electrically conducting polymers are intriguing as composite electrode additives since conceptually they can fulfill the roles of both carbon and binder.
Magnetite is a naturally occurring mineral found in the earth’s crust; therefore, it is abundant, environmentally friendly, cheap, and non-toxic. Magnetite is also easy to synthesize and can be prepared through simple, non-hazardous techniques such as through a facile aqueous co-precipitation method. Complete reduction of magnetite involves the transfer of 8 electrons, providing opportunity for an impressive capacity of 925 mAh/g. Notably, the initial reactions are insertion reactions where the lithium ion can insert into the Fe3O4 structure with minimal structural distortion, while upon further reduction, a conversion reaction occurs generating Fe metal and Li2O as products of full discharge.
To further probe the role of the electrically conductive polymer in the mesoscale (bulk) properties of composite electrodes, this study focuses on the Fe3O4 conversion reaction and its relationship to the electrically conductive polymer binder, PPy, including a detailed study of composite electrodes with nanoscale Fe3O4 and PPy. Magnetite, Fe3O4, with 6% and 20% polypyrrole (PPy) was used to prepare composite electrodes with and without added carbon.
Galvanostatic cycling and Electrochemical Impedance Spectroscopy (EIS) measurements were used in tandem to determine delivered capacity, capacity retention, and the related impedance at various stages of discharge and charge. Further, the reversibility of Fe3O4 to iron metal conversion observed during discharge was quantitatively assessed, ex situ, using X-ray Absorption Spectroscopy (XAS). The Fe3O4 composite containing the largest weight fraction of PPy (20 wt%) with added carbon demonstrated reduced irreversible capacity on initial cycles and improved cycling stability over 50 cycles. This study illustrated the beneficial role of PPy addition to Fe3O4 based electrodes partially related to improved electrical conductivity and also to improved ion transport related to the formation of a more favorable surface electrolyte interphase (SEI).
Nickel Phosphides as Catalysts for Direct Electrochemical CO2 Reduction to Important Renewable Polymers
Authors: Calvinho Karin U. D. , Laursen Anders B. , Goetjen Timothy A. , Greenblatt Martha , Dismukes Gerard Charles 
Published: February 2020

Copper1 and noble-metal alloys2 have been shown to catalyze the electrochemical reduction of CO2 to hydrocarbons such as methane (C1) and ethylene (C2). C1 and C2 hydrocarbons are the simplest building blocks for the synthesis of most industrial products and are therefore common chemical feedstocks. However, the production of hydrocarbons in aqueous solution is highly energy-consuming mainly due to the over-potential needed to overcome the transition states in C1 and C2 synthesis. In addition, there are significant efficiency losses due to the concomitant H2 production that is kinetically and thermodynamically favored under these conditions. As ethylene and methane from fossil source are comparatively cheap, the high cost of electricity makes the production of these simple hydrocarbons prohibitively expensive.
We have developed a noble metal free catalyst that is able to reduce carbon dioxide to hydrocarbons at lower over-potentials than copper (-0.6 V vs RHE), with significant suppression of the hydrogen production compared to the CO2 free environment. In addition, by changing the reactor configuration, CO2 may now be converted to a valuable polymer with composition akin to an aldehyde-carbonate co-polymer. This solid product can easily be de-polymerized to its parent monomers by changing pH. The resulting complex organic acids and aldehydes produced in at only -0.9 V vs RHE, have a significantly increased value to the simple hydrocarbons making this a very promising technology.
Supported by the BASF Corporation Catalysis Division Fellowship.

References:

(1) Hori, Y.; Kikuchi, K.; Suzuki, S. Chem. Lett.
1985, No. 11, 1695–1698.
(2) Kortlever, R.; Peters, I.; Balemans, C.; Kas, R.; Kwon, Y.; Mul, G.; Koper, M. T. M. Chem. Commun.
2016, 52, 10229–10232.