bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrocoagulation (EC) for the Removal of Silica from Mining ARD Water Treatment
Authors: Xie Zhong , Dy Eben , Qu Wei 
Published: February 2020

During the nanofiltration (NF) and reverse osmosis (RO) process, ions in the reject stream becomes increasingly concentrated. NF/RO concentrates from the treatment of mining acid rock drainage (ARD) water contain high levels various impurities—depending on the geochemistry of the waste rock and the treatment processes applied. Presence of cross-linked fine colloidal particles, especially silica, at certain levels in NF/RO concentrate streams can cause membrane fouling creating significant operational and water management challenges.
Electrocoagulation (EC) is a mature technology for many types of industrial waste water treatments. The technology can remove metal ions, colloidal suspensions, fine particles, and soluble inorganic pollutants from aqueous solution by introducing highly charged polymeric metal hydroxide species. In this paper, EC is explored as a treatment option for concentrated ARD water with focus in silica removal. Fe metal plates were employed as sacrificial electrodes. The experiments systematically investigate the influence of pH, dissolved oxygen (DO), current density (CD), and duration on the formation of green rusts (GRs) and silica removal. Batch tests have proved the concept that EC is a viable approach for silica removal from 80% RO reject water. Silica can be reduced from ~14 ppm down to ~3.0 ppm under 25mA/cm2 current density for 60 minute or 12.5 mA/cm2 for 120mins. Such level of silica removal can alleviate membrane fouling during subsequent NF/RO treatment. The DO level in solution has an important influence on pH and water chemistry, governs ferrous or ferric or ferrous/ferric mixed GR generation, and impacts the removal of silica in RO rejects from ARD water. EC with ferrous green rust formation under lowest DO level is best for silica removal.
Electrosynthesis of Hypochlorous Acid in a Filter-Press-Type Reactor Equipped with Ir-Sn-Sb Oxide Anode
Authors: Murrieta Maria Fernanda , Nava José Luis 
Published: February 2020

A wide range of advanced oxidation technologies have been used for water treatment, especially those contaminated by organic pollutants. Electro-Fenton-based process have been used to remove these pollutants due to the production of hydroxyl radicals (•OH). A new electrochemical Fenton-type process between electrogenerated hypochlorous acid and Fe2+ have been reported to produce hydroxyl radicals [1]. Recent study has shown the capacity of this Fenton-like process to remove a textile dye [2]. In this context, this research deals with the characterization of the electrosynthesis of hypochlorous acid from the oxidation of Cl- to be use in the future in a Fenton-like process. Microelectrolysis studies were performed to determine the anode potential range (1.6 < E < 1.9 V vs SHE) to avoid side reactions like oxygen evolution reaction, using 0.05 dm3 solution with 25 mM Na2SO4 + 35 mM NaCl at pH 3. The characterization of the electrosynthesis of active chlorine (mixture of hypochlorous acid, chlorine, and hypochlorite) was carried out in an undivided cell equipped with Ir-Sn-Sb oxide anode and stainless-steel cathode. The production of active chlorine by bulk electrolysis was formed at three anodic potentials (1.6, 1.7 and 1.9 V vs SHE) using 6 dm3 of electrolyte in recycle batch mode of operation at volumetric flow rate of 3.2 dm3 min-1 obtaining a chlorine concentration of 0.32 mM HClO, as shown in Figure 1. The influence of current density and volumetric flow rate on the conversion of active chlorine was carried out at 5 ≤ j ≤ 20 mA cm-2 and 0.8 ≤ Q ≤ 3.2 dm3 min-1, respectively. The best electrolysis was obtained at 15 mA cm-2 and 3.2 dm3 min-1, giving values of 20 % of current efficiency with energy consumption of 4 KW h m-3 for a production of 1.9 mM HClO. To elucidate if the active chlorine was reduced at the cathode, electrolysis trials were performed using the same electrolyser, which included a cationic membrane between electrodes.
References.
[1] K. Kishimoto, E. Sugimura, Water Sci. and Technol. 62 (210) 2321.
[2] Z.G. Aguilar, E. Brillas, M. Salazar, J.L. Nava, I. Sirés, Appl. Catal. B: Environ. 206 (2017) 44.

Figure 1
Stabilized Capacitive Deionization Via Voltage-Based Modification
Authors: Gao X. , Omosebi A. , Landon J. , Liu K. 
Published: February 2020

Fresh water scarcity is a major threat to sustaining human activities. As noted, approximately 1.1 billion people worldwide lack access to potable water, and a total of 2.7 billion people find water scarce for at least one month of the year.1 Therefore, efficient, cost-effective, and environmentally friendly desalination technologies need to be developed to secure water accessibility. Capacitive deionization (CDI) is an electrochemical water treatment technology possessing low-pressure operation, minimized maintenance costs, environmental friendliness, and possibly higher energy efficiency than contemporary desalination technologies.2

In literature, diminished salt separation of a CDI unit is often reported during repetitive charging and discharging cycles, along with inversion behavior, i.e., desorption peaks at the beginning of charging (or adsorption) steps, which is primarily accounted for by electrochemical oxidation at the carbon anode (or the positive electrode).3 Such concern recently provoked several studies focusing on how to retain salt separation while mitigating anode oxidation. Successful methods can be summarized as follows: reduction of the charging voltage,4 use of ion-exchange materials,5 use of alternating polarization,6 operation under inverted CDI (i-CDI) mode,7 and modification of the carbon surface.8 These efforts have facilitated the development of CDI technology so as to alleviate the threat of water crisis.
In this meeting, we present the use of advanced voltage-based modification to stabilize the capacitive deionization process using predominantly microporous carbon electrodes. The mechanism of the modification on performance improvement will be explained through potential distribution measurements and the modified Donnan (mD) model.
1. https://www.worldwildlife.org/threats/water-scarcity. (Last access: Nov-09-2017)
2. Suss, M. E.; Porada, S.; Sun, X.; Biesheuvel, P. M.; Yoon, J.; Presser, V., Energy Environ. Sci.
2015, 8, 2296-2319
3. Gao, X.; Omosebi, A.; Landon, J.; Liu, K., J. Electrochem. Soc.
2014, 161, E159-E166.
4. Cohen, I.; Avraham, E.; Bouhadana, Y.; Soffer, A.; Aurbach, D., Electrochim. Acta
2013, 106, 91-100.
5. Omosebi, A.; Gao, X.; Landon, J.; Liu, K., ACS Appl. Mater. Interf.
2014, 6, 12640-12649.
6. Gao, X.; Omosebi, A.; Holubowitch, N.; Landon, J.; Liu, K., Electrochim. Acta
2017, 233, 249-255.
7. Gao, X.; Omosebi, A.; Landon, J.; Liu, K., Energy Environ. Sci.
2015, 8, 897-909.
8. Krüner, B.; Srimuk, P.; Fleischmann, S.; Zeiger, M.; Schreiber, A.; Aslan, M.; Quade, A.; Presser, V., Carbon
2017, 117, 46-54
Effect of the Oxygenated Diamond Surface on the Electrochemical Oxidation of DBT and 4,6-DMDBT
Authors: Ornelas-Dávila Omar , Lacalle-Bergeron Leticia , Dávila-Jiménez M. M. , Beltrán-Arandes Joaquim , Roig- Navarro Antoni Frances , Sancho- Llopis Juan Vicente 
Published: February 2020

Boron-doped diamond (BDD) has been extensively studied by their ability to oxidize a wide range of contaminants in liquid mixtures. These electrodes have a wide potential window margin for water discharge and stability for extended periods of time (1,2). However their electrochemical activity depends on the surface composition and the degree of crystallinity. On the other hand, electrochemical oxidation techniques have received great importance in the electrochemical desulfurization of organic sulfur compounds (3,4). In the present work electrochemical oxidation of DBT and 4,6-DMDBT was studed using BDD electrode in acetonitrile-water medium (electrolyte). Also was studied the oxidation of above compounds mentioned on the preoxygenated diamond surface by VMC, Chronoamperometry and electrolysis at constant potentials. The results showed that the oxygenated species on the surface of the BDD electrode influence the electrode-analyte interactions, the kinetics and the mechanism of the oxidation process. The analysis of the extracts after the electrochemical oxidation of DBT and 4,6-DMDBT by GC / MS and HPLC-MS / MS showed that the oxidation is selective. At potentials lower than 1.75V, the main product is the formation of sulfoxide, while at potentials greater than 1.75V it is the corresponding sulfone. A mixture of sulfoxide, sulfone and other oxidation products was obtained due to the opening of the aromatic ring for potentials greater than 2.0 V and prolonged electrolysis times.
Bibliography

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Méndez-Albores, M. A. González-Fuentes, M. M. Dávila-Jiménez, F. J. González. Journal of Electroanalytical Chemistry 751 (2015) 7–14

Lam, G. Li, C. Song, J. Chen, C. Fairbridge, R. Hui, J. Zhang. Fuel Processing Technology 98 (2012) 30-38
(Invited) Electrochemical Capacitors: Deconvolution into Capacitive and Pseudocapacitive Contributions By in-Situ Time-Resolved Optical Methods
Authors: Scherson Daniel 
Published: February 2020

Despite years of research questions still remain regarding the underlying physicochemical bases of charge storage in electrochemical capacitors. Much of the controversy centers around the nature of the processes responsible for this phenomenon. Work in our laboratories has focused on dynamic aspects of charge injection into IrOx(hyd) in strongly acid aqueous media, as monitored simultaneously by chronocoulometric and time-resolved differential reflectance techniques. We have taken full advantage of the electrochromic properties of these films which makes it possible to monitor changes in the oxidation state of the Ir sites in the films and thus resolve the electrochemical response in terms of its purely capacitive and pseudocapacitive components.
Shown in the figure below are plots of ΔR/R vs time (left ordinate) and the integrated charge, Q, based on the integration of the current (right ordinate), following potential steps between (Eini → Efin) (left panels) and (Efin → Eini) (right panels) for Eini = 0.20 V and Efin = 0.67 (upper panels) and Efin = 0.60 V (lower panels). The ordinates in the two curves in each panel were adjusted so as to match the initial and final values of ΔR/R and Q. It is important to stress is that the measured time constants for both the charge and optical measurements are on the order of a few tenths of seconds, and thus much longer than the RC time constant estimated based on the electrode dimensions and conductivity of the electrolyte (see above), which would yield values on the order a fraction of a ms.
Careful inspection of these curves (as well as those involving all other values of Efin examined, revealed two important features:

the oxidation process is faster than the subsequent reduction, and, most importantly,

the rate at which total charge injection and release occurs, as judged by the electrochemical data, appears faster than that at which the Ir sites undergo redox transitions, as evidenced from the optical data. This phenomenon strongly suggests that charge can be stored in the film involving both non-redox (fast) and redox (slow) sites.

Figure 1
(Invited) Redox Mechanistic Effects on Pseudo-Capacitive Electrode Behaviour
Authors: Donne Scott W 
Published: February 2020

Much ado has been made about the contributions that redox processes made to pseudo-capacitive electrode performance. Many apparently similar materials such as RuO2, MnO2 and NiOOH contribute charge through redox processes at the electrode surface; however, their performance can be quite different depending on the electrode properties and environment. The typical response for an electrochemical capacitor electrode is a box-like voltammogram; however, materials such as these have a basis of such behaviour, but may also include distinct redox peaks within the voltammogram.
Here we will examine the role that the redox mechanism for these psuedo-capacitive materials has on electrode performance, as well as investigate its impact on electrode properties, in particular crystal size. Outcomes will allow further differentiation of materials used in electrochemical capacitors.
Spray Dried Cerium Oxide/Graphene/Polyaniline Composite for Supercapacitor Applications
Authors: Jeyaranjan Aadithya , Seal Sudipta 
Published: February 2020

Supercapacitor materials can be broadly classified into three types: carbon based, metal oxide based and conductive polymers. Though, each of these materials has their own advantages, they also have unique drawbacks, like poor cycle life for conductive polymers, inherently low conductivity for most metal oxides and low energy density for carbon based material. In the study, a composite of these three materials is synthesized through an easily scalable process to yield a supercapacitor material with high specific capacitance, excellent rate capability and cycle life.
Micron sized cerium oxide (CeO2)/graphene/polyaniline (PANI) composites are synthesized using spray-drying and chemical reduction. First, graphene oxide/PANI composites are prepared by an in-situ polymerization technique. A hydrothermally one-step process is used synthesized CeO2 nanoparticles. These raw materials are then thoroughly mixed through ultrasonication and spray dried at 200°C. The use of PANI has two benefits. One, it acts as a binder between the inorganic CeO2 nanoparticles and GO during the spray dried process to yield micron sized spherical particles. Second, PANI also forms a uniform highly conductive layer, which boosts the electronic transmission and thereby the supercapacitance of the composite. The CeO2 improves the poor cycle life of PANI. The random stacking and agglomerating of GO and CeO2 during the spray drying process produces numerous channels which acts as pathways for the electrolytic ions. Thus the individual elements work synergistically to improve the supercapacitor performance.
The synthesized composites have been structurally characterized using XRD, FTIR and SEM. The electrochemical properties have been evaluated in standard three-electrode set-up with 3M KOH electrolyte using cyclic voltammetry, galvanostatic charge discharge curves and impedance analysis. The results from the electrochemical analysis show that the spray dried composite material show high specific capacitance, energy density and long cycle life.
(Invited) Ionogels for Safer Energy Storage: The Determining Effect of the Interface
Authors: Le Bideau Jean , Asbani Bouchra , Douard Camille , Dupré Nicolas , Humbert Bernard , Marie Angélique , Brousse Thierry , Lethien Christophe 
Published: February 2020

Ionogels represent a route to biphasic materials, for the use of ionic liquids (ILs) for all-solid devices. Confining ILs within host networks enhances their averaged dynamics, resulting in improved charge transport. Fragility, short relaxation times, low viscosity, and good ionic conductivity, all them appear to be related to the IL / host network interface. The presence of ILs at interface neighborhood leads to the breakdown of aggregated, structured regions that are systematically found in bulk ILs. This “destructuration”,1 as well as segregative interactions at interface,2 coupled with percolation of the bicontinuous solid/liquid interface,3 make these materials very competitive among the existing solid electrolytes. Such approach could provide (i) a route to lower locally the viscosity of ILs, and (ii) an easier pathway for diffusion of charged species. Several types of ionogels demonstrate this effect, taking into account of fully inorganic, hybrid, polymeric or organic-inorganic host networks . This “all-solid” approach can be applied to several electrochemical energy storage sources, including lithium batteries (Fig 1)2,4 and supercapacitors (Fig. 2).5 Strikingly, high performance were shown on these devices, thanks to interfacial effects of confined ILs, with sometimes heightened properties of the chosen ILs as referred to their bulk properties.2,3,6 Such solid electrolytes are particularly well suited for microdevices that we have been or are being developed (Fig. 3).5,6 Herein we will emphasize the results of a systematic study of the effect of size of confinement.
References:
[1] A. Guyomard-Lack et al., Phys. Chem. Chem. Phys., 16 (2014) 23639-23645.
[2] A. Guyomard-Lack et al., New J. Chem., 40 (2016) 4269-4276.
[3] C. V. Cerclier et al., Phys. Chem. Chem. Phys., 17 (2015) 29707—29713
[4] D. Aidoud et al., J. Power Sources, 330 (2016) 92-103
[5] M. Brachet et al., J. Mater. Chem. A, 4 (2016) 11835-11843.
[6] E. Eustache et al., Adv. Energy Mater., 5 (2015) 1500680

Figure 1
(Invited) Hybrid Electrodes and Materials for Hybrid Energy Storage
Authors: Gomez-Romero Pedro 
Published: February 2020

Energy storage is increasingly recognized as a key technology to enable our ongoing transition to a sustainable energy model. Electrochemical energy storage will be key to this transition but is still far from optimal. That is why there is still plenty of room for new and novel types of materials for batteries and for supercapacitors. Hybrid materials offer opportunities for synergy and new properties with respect to their components.[1] Those formed by electroactive and conducting components are of particular interest for energy storage applications.[2, 3, 10]
We have developed a whole line of work dealing with hybrid electroactive (oxides[9], phosphates[4] polioxometalates[5-8]) and conductive materials (conducting polymers or carbons) for energy storage applications.[4-9] In this conference we will address the different approaches towards hybridizing energy storage by taking the hybridization concept to a chemical level and will discuss the several multifunctional synergies hybrids provide. In particular, in addition to conductive-electroactive combinations, we will show how hybrids can be designed to take advantage of dual energy storage mechanisms by combining the typical capacitive behavior of supercapacitors with the characteristic faradaic activities of batteries, thus, blurring the borderlines between these two types of devices.[10]
[1] P. Gomez-Romero Adv.Mater. 2001, 13(3), 163.
[2] P. Gomez-Romero et al. J.Solid State Electrochem. 2010 14(11), 1939
[3] Ait Salah et al. J.Electrochem.Soc. 2006, 153(9), A1692.
[4] A. Fedorkova et al. Electrochim.Acta 2010, 55(3), 943
[5] J. Vaillant et al. Progress in Solid State Chemistry, 2006, 34, 147.
[6] V. Ruiz, J. Suárez-Guevara, P. Gomez-Romero Electrochem. Communications 2012, 24, 35.
[7] J. Suarez-Guevara, V. Ruiz and P. Gomez-Romero J.Mat.Chem.A, 2014, 2, 1014.
[8] D P Dubal, et al. Journal of Materials Chemistry A 2015, 3(46), 23483
[9] D P. Dubal, R. Holze, P. Gomez-Romero. Scientific Reports 2014, 4 : 7349
[10] D.P. Dubal, V. Ruiz, O. Ayyad and P. Gomez-Romero Chem.Soc.Rev. 2015 44(7):1777-90
Synthesis and Characterization of Manganese (IV) and Cobalt (II/III) Oxides Based on Graphene for Supercapacitors Application
Authors: Jablonskienė Jolita , Šlopšnys Justinas , Pakštas Vidas , Vaičiūnienė Jūratė , Drabavičius Audrius , Jasulaitienė Vitalija , Tamašauskaitė-Tamašiūnaitė Loreta , Norkus Eugenijus 
Published: February 2020

As an ideal electrochemical energy storage candidate, supercapacitors have gained increasing attention due to high power density, long cycle life and fast charge/discharge rate, which is more suitable for large power components. Conventional lithium-ion batteries are widely used in portable electronic equipment such as laptop computers, cell phones and electric vehicles.
In this study, the graphene supported manganese (IV) oxide (MnO2/GR), cobalt (II/III) oxide (Co3O4/GR) and manganese-cobalt oxide (MnO2-Co3O4/GR) nanocomposites were synthesized using the microwave irradiation method. The synthesized composites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical performance of the graphene supported MnO2, Co3O4 and MnO2-Co3O4 nanocomposites was evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge.
The graphene supported MnO2-Co3O4 nanocomposites have significant influence on the electrochemical performance as compared with that of the MnO2/GR and Co3O4/GR. The maximum specific capacitance of 152 F g-1 was achieved at the MnO2-Co3O4/GR in the 1 M Na2SO4 aqueous solution at the scan rate of 10 mV s-1.

Acknowledgement

This research is funded by the European Social Fund under the No. 09.3.3-LMT-K-712-02-0142 “Development of Competences of Scientists, other Researchers and Students through Practical Research Activities” measure.
Anodic TiO2 Nanotube Layers: Excellent Platform for Secondary Materials
Authors: Zazpe Raul , Krbal Milos , Prikryl Jan , Sopha Hanna , Dvorak Filip , Macak Jan M. 
Published: February 2020

The self-organized TiO2 nanotube layers have attracted considerable scientific and technological interest over the past 10 years, which are motivated for their possible range of applications including photo-catalysis, solar cells, hydrogen generation and biomedical uses [1]. The synthesis of 1D TiO2 nanotube structure is carried out by a conventional electrochemical anodization of Ti sheet. The main drawback of TiO2 is its applicability in the UV light (wavelengths < 390 nm).
Atomic layer deposition (ALD) has been shown to be an effective technique to coat TiO2 nanotube layers homogenously with secondary materials. Ultrathin surface coating of TiO2 by secondary materials such as Al2O3 [2], ZnO [3] or MgO [4] annihilates electron traps at the TiO2 surface and thus increases the concentration of the photogenerated charge carriers.
This presentation will focus in detail on the coating of the nanotube layers with different (high) aspect ratios by various secondary materials using ALD. We will show initial photo-electrochemical results for anodic TiO2 nanotubes employed as highly ordered electron-conductive supports for host materials coated using ALD with secondary materials to enhance light absorbing capabilities of such hybrid systems. Experimental details and some very recent photocatalytic [5, 6], sensing [7] and solar cell [8] results will be presented and discussed.
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