Potential Applications Research Articles

Comparative Study of Vital Sign Monitoring Techniques and Methods using Radar Sensor

COVID-19 (Corona Virus Disease of 2019) is a global pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) virus. This disease has significantly impacted every aspect of people's lives, including their work style, leisure activities, and use of technology. Additionally, due to psychological factors or other reasons, there has been a surge in deaths from cardiovascular failure during the pandemic. As COVID-19 is a silent killer whose symptoms only become visible after significant damage has been done, constant monitoring of heart parameters is crucial to address this issue. This paper explores the emerging trends in monitoring vital signs such as the electrocardiogram (ECG), heart rate, respiration rate (breaths), related sensors, remote sensor organization, and telemedicine innovations. Furthermore, this paper discusses the potential application of non-contact radar-based remote monitoring for vital sign monitoring of affected patients.

Iono‐Optic Impedance Spectroscopy (I‐OIS): A Model‐Less Technique for In Situ Electrochemical Characterization of Mixed Ionic Electronic Conductors

AbstractFunctional properties of mixed ionic electronic conductors (MIECs) can be radically modified by (de)insertion of mobile charged defects. A complete control of this dynamic behavior has multiple applications in a myriad of fields including advanced computing, data processing, sensing or energy conversion. However, the effect of different MIEC's state‐of‐charge is not fully understood yet and there is a lack of strategies for fully controlling the defect content in a material. In this work we present a model‐less technique to characterize ionic defect concentration and ionic insertion kinetics in MIEC materials: Iono‐Optic Impedance Spectroscopy (I‐OIS). The proof of concept and advantages of I‐OIS are demonstrated by studying the oxygen (de)insertion in thin films of hole‐doped perovskite oxides. Ion migration into/out of the studied materials is achieved by the application of an electrochemical potential, achieving stable and reversible modification of its optical properties. By tracking the dynamic variation of optical properties depending on the gating conditions, I‐OIS enables to extract electrochemical parameters involved in the electrochromic process. The results demonstrate the capability of the technique to effectively characterize the kinetics of single‐ and even multi‐layer systems. The technique can be employed for studying underlying mechanisms of the response characteristics of MIEC‐based devices.

On machine learnability of local contributions to interatomic potentials from density functional theory calculations

Machine learning interatomic potentials, as a modern generation of classical force fields, take atomic environments as input and predict the corresponding atomic energies and forces. We challenge the commonly accepted assumption that the contribution of an atom can be learned from the short-range local environment of that atom. We employ density functional theory calculations to quantify the decay of the induced electron density and electrostatic potential in response to local perturbations throughout insulating, semiconducting and metallic samples of different dimensionalities. Molecules and thin layers are shown to fail keeping such disturbances localized. Therefore, the learnability of local atomic contributions, which guarantees scalability and transferability of a machine learning interatomic potential, is questionable in the case of molecules and low-dimensional samples. Similarly, the induced electrostatic effects due to substituted impurities or vacancy sites in a crystalline bulk are weakly damped and remain significant beyond several interatomic distances. However, geometric deformations in bulks are practically local within the first neighbors and induce a Yukawa-type electrostatic potential that exponentially vanishes. The practical importance of this finding is that it limits the application of the machine learning interatomic potentials to conformational search or thermal properties of bulk materials and so on, where only purely geometrical deformations are involved. Once chemically impactful defects like aliovalent impurities or vacancies are present, the interatomic potentials trained on local environments need to be corrected for long-range effects.

Constrained Heterogeneous CoFe2O4/ZnO/PMS Fenton-Like System for Industrial Wastewater Remediation with Recyclability and Zero Metal Loss.

Although heterogeneous Fenton-like processes have attracted widespread attention in wastewater treatment, the mass leached active ions lead to secondary pollution and confuse the demarcation of reaction region. By constructing a constrained completely heterogeneous system and highlighting its reaction region concentrated within the slipping plane of particles, this work achieves efficient organic pollutants degradation without leaching of any free active metal components. Based on the Poisson-Boltzmann equation and electric double layer model, the specific existing of the constrained region is confirmed, and this neglected reaction region between solid interface and slipping plane in traditional heterogeneous Fenton-like reaction is clarified firstly. Due to the unique constrained property, this system demonstrates exceptional potentials application to natural water and actual industrial wastewater for its broad resistance to environmental interference. Furthermore, the alkalization aging process enables this system achieve catalyst recycle and zero metal ions emission with maintaining outstanding pollutants removing performance even in high-salt wastewater, exhibiting the superiority of the constrained completely heterogeneous system. This work demonstrated the important reaction region within slipping plane and provided a clearer boundary in heterogeneous Fenton-like system.

Constrained Heterogeneous CoFe2O4/ZnO/PMS Fenton‐Like System for Industrial Wastewater Remediation with Recyclability and Zero Metal Loss

Although heterogeneous Fenton‐like processes have attracted widespread attention in wastewater treatment, the mass leached active ions lead to secondary pollution and confuse the demarcation of reaction region. By constructing a constrained completely heterogeneous system and highlighting its reaction region concentrated within the slipping plane of particles, this work achieves efficient organic pollutants degradation without leaching of any free active metal components. Based on the Poisson‐Boltzmann equation and electric double layer model, the specific existing of the constrained region is confirmed, and this neglected reaction region between solid interface and slipping plane in traditional heterogeneous Fenton‐like reaction is clarified firstly. Due to the unique constrained property, this system demonstrates exceptional potentials application to natural water and actual industrial wastewater for its broad resistance to environmental interference. Furthermore, the alkalization aging process enables this system achieve catalyst recycle and zero metal ions emission with maintaining outstanding pollutants removing performance even in high‐salt wastewater, exhibiting the superiority of the constrained completely heterogeneous system. This work demonstrated the important reaction region within slipping plane and provided a clearer boundary in heterogeneous Fenton‐like system.

MXenes Spontaneously Form Active and Selective Single-Atom Centers under Anodic Polarization Conditions.

Single-atom catalysts (SACs) have emerged as a new class of materials for the development of active and selective catalysts. These materials are commonly based on anchoring a noble transition metal to some kind of carrier. In the present work, we demonstrate that MXenes─two-dimensional materials with application in energy storage and conversion─spontaneously form SAC-like sites under anodic polarization conditions, using the applied electrode potential as a probe to form catalytically active surface sites reminiscent of a SAC-like structure. Combining ab initio molecular dynamics simulations and electronic structure calculations in the density functional theory framework, we demonstrate that only the SAC-like sites rather than the basal planes of MXenes are highly active and selective for the oxygen evolution or chlorine evolution reactions, respectively. Our findings may simplify synthetic routes toward the formation of active and selective SAC-like sites and could pave the way for the development of smart materials by incorporating fundamental principles from nature into material discovery: while the pristine form of the material is inactive, the application of an electrode potential activates the material by the formation of active and selective single-atom centers.

Artificial Intelligence for Breast Ultrasound: AJR Expert Panel Narrative Review.

Breast ultrasound is used in a wide variety of clinical scenarios, including both diagnostic and screening applications. Limitations of ultrasound, however, include its low specificity and, for automated breast ultrasound screening, the time necessary to review whole-breast ultrasound images. As of this writing, four AI tools that are approved or cleared by the FDA address these limitations. Current tools, which are intended to provide decision support for lesion classification and/or detection, have been shown to increase specificity among nonspecialists and to decrease interpretation times. Potential future applications include triage of patients with palpable masses in low-resource settings, preoperative prediction of axillary lymph node metastasis, and preoperative prediction of neoadjuvant chemotherapy response. Challenges in the development and clinical deployment of AI for ultrasound include the limited availability of curated training datasets compared with mammography, the high variability in ultrasound image acquisition due to equipment- and operator-related factors (which may limit algorithm generalizability), and the lack of postimplementation evaluation studies. Furthermore, current AI tools for lesion classification were developed based on 2D data, but diagnostic accuracy could potentially be improved if multimodal ultrasound data were used, such as color Doppler, elastography, cine clips, and 3D imaging.

Delivery Systems for Plasma-reactive Species and their Applications in the Field of Biomedicine.

Cold atmospheric plasma (CAP) is an ionized matter with potential applications in various medical fields, ranging from wound healing and disinfection to cancer treatment. CAP's clinical usefulness stems from its ability to act as an adjustable source of reactive oxygen and nitrogen species (RONS), which are known to function as pleiotropic signaling agents within cells. Plasma-activated species, such as RONS, have the potential to be consistently and precisely released by carriers, enabling their utilization in a wide array of biomedical applications. Furthermore, understanding the behavior of CAP in different environments, including water, salt solutions, culture medium, hydrogels, and nanoparticles, may lead to new opportunities for maximizing its therapeutic potential. This review article sought to provide a comprehensive and critical analysis of current biomaterial approaches for the targeted delivery of plasma-activated species in the hope to boost therapeutic response and clinical applicability.

Microbial self-healing cement-based materials co-reinforced by Mg2+: using recycled aggregates as carriers

Microbial self-healing cementitious materials have attracted widespread attention due to their targeted repair of cracks, but their practical application is limited by cost. In this study, self-healing mortar was prepared using recycled concrete fine aggregate as a cementitious material to investigate the effect of magnesium ions on crack repair, to explore the compatibility of self-healing components and cement, and to assess the cost and environmental impact of this self-healing mortar. The results showed that the mineralization efficiency was the highest at 31.1% with a Ca/Mg molar ratio of 3, and the 28 d crack repair rate reached 97.8%; yeast and peptones in the self-repairing system slowed down the rate of cement hydration, whereas magnesium chloride and calcium lactate facilitated the hydration reaction. The use of recycled concrete fine aggregate (RCA) reduces the cost of the self-repairing material and the CO2 emission, and improves the application of microbial self-healing cementitious materials potential.

A Recent Update on the Visible Light-promoted Organic Transformations - A Mini-review.

Visible light-induced reactions are a rapidly developing and powerful technique to promote organic transformations. They provide green and sustainable chemistry and have recently received increasing attention from chemists due to their wide application in organic synthesis. Light energy is eco-friendly, cheap, green, and inexhaustible with potential industrial and pharmaceutical applications. In this review, the most recent advances in visible light-induced reactions (2021-till date) have been highlighted.

In-silico Docking and Dynamics Simulation Analysis of Peroxisome Proliferator-Activated Receptor-Gamma and β-Carotene

Background: Peroxisome proliferator-activated receptor-gamma (PPAR-γ) plays a crucial role in regulating lipid and glucose metabolism, cancer, and inflammation, making it an attractive target for drug development. Meanwhile, β-Carotene, known for its antioxidant, anticancer and antiinflammatory properties, holds promise for modulating PPAR-γ activity. Understanding their interaction is crucial. Objective: This study aims to explore the therapeutic potential of β-carotene in modulating PPAR-γ activity by investigating their binding interactions. Methods: Screening of bioactive compounds from PubChem was conducted using GlideXP to identify potential PPAR-γ (PDB: 2PRG) ligands. During this screening, both protein and bioactive compounds were prepared following established protocols. Subsequently, the compounds were docked into the ligand binding domain (LBD) of the protein using XP docking. Rosiglitazone was used as an internal control. β-Carotene emerged as a lead based on Lipinski’s rule, docking score, free energy, and LBD interactions. Molinspiration analysis assessed its drug likeness. Molecular dynamics (MD) simulations utilizing Desmond with OPLS 2005 force field were employed to examine the dynamics and stability of the PPAR-γ/β-carotene complex. Results: β-carotene had strong hydrophobic interactions with specific residues within the ligandbinding domain of PPAR-γ. The calculated binding affinity (-9.07 kcal/mol) indicated a strong interaction between β-carotene and PPAR-γ, suggesting that β-carotene may modulate the activity of PPAR-γ. On a time scale of 100 ns, the MD simulations provided insights into the conformational changes, flexibility, and intermolecular interactions within the complex. Conclusion: In silico docking and dynamics simulation analyses show that PPAR-γ and β-carotene can form a stable complex, suggesting potential implications for metabolic modulation.

Automation of Drug Discovery through Cutting-edge In-silico Research in Pharmaceuticals: Challenges and Future Scope.

The rapidity and high-throughput nature of in silico technologies make them advantageous for predicting the properties of a large array of substances. In silico approaches can be used for compounds intended for synthesis at the beginning of drug development when there is either no or very little compound available. In silico approaches can be used for impurities or degradation products. Quantifying drugs and related substances (RS) with pharmaceutical drug analysis (PDA) can also improve drug discovery (DD) by providing additional avenues to pursue. Potential future applications of PDA include combining it with other methods to make insilico predictions about drugs and RS. One possible outcome of this is a determination of the drug potential of nontoxic RS. ADME estimation, QSAR research, molecular docking, bioactivity prediction, and toxicity testing all involve impurity profiling. Before committing to DD, RS with minimal toxicity can be utilised in silico. The efficacy of molecular docking in getting a medication to market is still debated despite its refinement and improvement. Biomedical labs and pharmaceutical companies were hesitant to adopt molecular docking algorithms for drug screening despite their decades of development and improvement. Despite the widespread use of "force fields" to represent the energy exerted within and between molecules, it has been impossible to reliably predict or compute the binding affinities between proteins and potential binding medications.

Concreto com gradação funcional: gradação na porosidade para o aumento da durabilidade frente à carbonatação

Abstract The present paper evaluated the potential application of the functionally graded material (FGM) concept to develop more durable concrete to carbonation, one of the main degradation mechanisms of reinforced concrete structures. Accelerated carbonation tests with controlled temperature (27 ( 2°C), CO2 concentration (3 ( 0.5%) and humidity (65 ( 5%) were carried out in homogeneous concretes and with functional gradation in which the porosity of the material was varied across the slices. For the manufacture of graded concrete specimens, concretes with water/cement ratios equal to 0.35, 0.45, and 0.55 were produced, with lower porosity (w/c = 0.35) close to the surface of the specimen. The advance of the carbonation front was evaluated after 8, 9, 10, 14, and 24 weeks of accelerated exposure, using the chemical indicator phenolphthalein. The results show that the functionally graded concrete had a carbonation coefficient (K) slightly higher than that of the concrete with a w/c ratio equal to 0.35 (1.71 and 1.54 mm.week-0.5, respectively) and much lower than concrete with water-cement ratio equal to 0.45 (2.31 mm.week-0.5) and 0.55 (3.78 mm.week-0.5). This demonstrates that functional grading can be an efficient method to increase the durability of concrete elements subject to carbonation.

In Situ Electrochemical Transmission Electron Microscopy of Transient Electrodeposition and Coarsening on Graphene

For heterostructures composed of metal nanoparticles and 2D materials, improving the precision of electrochemical fabrication requires a deep understanding of the interplay of kinetic and thermodynamic phenomena. Here, we explore the deposition of copper (Cu) metal on a graphene electrode using liquid cell transmission electron microscopy (TEM), using the temporal and spatial resolution of this technique to explore the nucleation and growth of nanocrystals. The technique reveals an unexpected transient phenomenon under certain applied voltage conditions, and we discuss possible mechanisms.We created working electrodes from few-layer graphene by transferring the crystals onto liquid cell chips patterned with platinum (Pt) electrodes. Pt was used as counter and quasi-reference electrodes. We then performed electrochemical deposition of Cu on graphene by controlling the deposition potential in an acidified copper sulfate solution. In situ movies reveal that during application of the potential, Cu nanocrystals nucleate and grow following the expected kinetics of progressive nucleation and diffusion-limited growth: larger numbers of smaller nanocrystals grow at more negative overpotentials. When the applied potential is low (-40 mV, -60 mV, -80 mV, and -100 mV with respect to Pt reference electrode), particles immediately dissolve as the potential is turned off.However, we observe that when more negative potentials (-180 mV, -220 mV, -240 mV and -260 mV) are used for deposition, the growth of Cu nanocrystals continues after the voltage goes off. Typical results are shown in the Figure. These images were extracted from a movie recorded during and after pulse voltammetry at -260 mV for 10 s in a liquid cell filled with 0.1 M CuSO4 + 0.1 M H2SO4. In the first row of the Figure, Cu islands nucleate and grow on the graphene electrode during the ‘V on’ period, while the later images show continued growth of Cu islands after the voltage is turned off at t=10 s. Eventually all islands disappear after tens of seconds. Tracking the size of the individual particles shows that smaller particles disappear earlier while the largest particles grow to large sizes. The decrease in the number of islands with time is particularly apparent at higher applied potentials, which is consistent with an Ostwald ripening process, and the size threshold that separates crystals that grow or shrink appears is also consistent with the model.The eventual dissolution of Cu nanocrystals in all experiments would not ordinarily be expected at zero applied potential. The comparison of cyclic voltammetry curves among different configurations of graphene electrodes suggests that there is an intrinsic potential between the graphene and Pt electrodes which is high enough to dissolve the deposited Cu even when the applied potential is 0 mV.We consider several mechanisms that may be responsible for the unexpected transient deposition. One possible explanation for the additional growth could be that Cu is deposited during the potential pulse but does not form into nanocrystals until later. This could arise if Cu is intercalated in the graphene during the applied potential. However, the measured charge that flows during the potential pulse is not strongly dependent on voltage, in particular not varying enough to account for the large deposited volume at high potentials. A second possible explanation may arise from the capacitance of graphene. Graphene has high capacitance based on electrochemical double-layer capacitance (EDLC) measurements, and it has been shown that the electrochemical interfacial capacitance increases for larger (negative) applied potential, which is consistent with our observation of the islands grown at larger potential last longer. A final mechanism for the effect could be that the application of low cathodic potential may cause the reduction of various oxygen functional groups forming species such as -OH. These charged species could sustain additional growth by reducing Cu ions from the solution. We will discuss this possible role of graphene to drive morphological changes during electrochemical processes, and consider wider opportunities that may arise for controlling electrodeposition to tailor thin film and nanoscale structures. Figure 1

Electrodeposition of Copper Clusters during Electrolytic Zinc Phosphating to Increase Nitrate Reduction Selectivity

Despite being one of the most widespread and well-established surface treatments, conversion phosphating is often scrutinized because of its negative impact on the environment. Electrolytic phosphate coatings are perhaps the primary candidates to lead the phasing out of the old conversion technology, while also offering similar material performance. [1] In this embodiment of the process, the formation of phosphate crystals is promoted by the application of a cathodic potential to the substrate, triggering hydrogen evolution (HER) and nitrate reduction (NO3R) at the interface. These two reactions consume H+ ions, leading to a local alkalinization of the electrolyte and eventually to phosphate precipitation. So far, very little attention has been placed on the effects of the two reactions on the coatings’ properties. On one hand, HER is driven by direct reduction of protons and will always take place as long as the electrolyte is acidic; on the other hand, the formation of H2 bubbles at the interface can interfere with the coating formation itself. Conversely, NO3R does not lead to formation of gas byproducts, but its contribution to the total cathodic current depends strongly on the activity of the substrate.In this work, we established a correlation between the properties of zinc phosphate coatings obtained by the electrolytic method and the NO3R activity of the substrate they are deposited on. For the purposes of the study, differential electrochemical mass spectrometry (DEMS) was used to evaluate the HER partial current density in-operando, under various NO3 - concentrations. In this regard, Au and Cu substrates were selected because of their widely different selectivity towards NO3R. [2] The results highlighted drastically improved properties for the zinc phosphate coatings obtained on copper, suggesting a positive correlation between substrate NO3R selectivity and zinc phosphate coating quality.The importance of these results is then discussed in relation to the treatment of low-alloy steel, which has the greatest relevance in industrial applications. In this regard, the coating weight of zinc phosphate coatings obtained under various NO3 - concentrations is evaluated and compared to copper. The findings are also corroborated with SEM and XRD measurements, to determine the coating morphology and composition.Finally, the addition of Cu2+ to the phosphating formulation is proposed as a mean to increase the selectivity towards NO3R during the deposition. Under the cathodic polarization maintained during the coating process, Cu2+ ions can be directly reduced on the steel surface, leading to the formation of metallic Cu clusters, which can then act as catalysts towards NO3R. Additions of Cu2+ as low as 5 mM in the solution led to improvements in the coating weight and homogeneity, indicating a better utilization of the NO3 - ions in solution.In conclusion, NO3R is found to have beneficial effects during the formation of phosphate coatings via the electrolytic deposition technology. Direct electrodeposition of metallic Cu clusters with minimal modification of the base electrolyte was found to be a viable method to improve the activity of the substrate towards NO3R. The findings of this study could help the development of novel electrolytes for electrolytic phosphating, with particular attention to other strategic alloys, such as those based on Mg and Al, that could greatly benefit from this technology.

Challenges in Accurate Calculation of Electrochemical Reactions Using First Principles Calculations: Water Adsorption on Pt(111) Surface Under Applied Potential

Modelling of chemical reactions controlled by an applied external potential could greatly enhance technological developments in the fields like electrochemical synthesis, fuel cells, water electrolysis and etc. Such modelling could be used for in silico search for more active and more stable catalysts, avoiding time consuming and costly experiments. However, a key prerequisite for reliable and successful modelling should be a close agreement between evaluated properties and their experimental observations.In this presentation the fundamental reaction of water interactions with a surface of Pt electrode is discussed. We chose this reaction as a useful illustrative example where available experimental measurements, such as potentials of water adsorption and dissociation on Pt surface could be directly compared to the modelling for benchmarking of a computational accuracy. Herein, the ability of an employed DFT-based method with implicit model of solution is tested, addressing challenges such as limitations in accurate evaluation of materials work functions, approximate model of solution and difficulties in total energy evaluation under the constant potential.As a first step, we point out to the problem of employing an experimental range of a potential of the standard hydrogen electrode (SHE), used as a reference in theoretical calculations in view of an inability of DFT to provide sufficiently accurate evaluation of materials work function and hence an operating potential. Secondly, we also show that upon hydration of a Pt surface there exists a peculiar non-monotonic change of a potential upon charging of a slab in contrast to monotonic relation for a clean Pt surface, which we explain by modification of water binding mechanism (presence of a dual charge in certain voltage range) with changing of a charge state of Pt surface (Fig. 1).To characterise the binding mechanism of a water molecule to Pt(111) surface we analysed the partial density of states, Fukui function and density matrices of p-states of an oxygen atom of a water molecule upon adsorption. Based on our calculations we conclude that greater binding upon application of a higher potential is accounted for by a charge accumulation in the Pt-O interatomic space, in spite of an overall total charge decrease.In summary our work provides a reliable methodology, that could be applied for analysis of reaction steps of electrochemical reactions on Pt surface under the applied external potential.This presentation is based on results obtained from a project, JPNP20003, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). Figure 1

Investigation of Phosphorus Refining in Hot Metal through Electrochemical Methods

This study investigates the enhancement of phosphorus removal from hot metal through electrochemical methods to promote sustainable steel production. It introduces electrolytic refining techniques using molten slag as an electrolyte, aiming to overcome the limitations of chemical refining based on conventional CaO-bearing slag.The research focused on the application of electric potentials to a CaO-SiO2-Al2O3-MgOsat slag system at a temperature of 1550℃ in a CO gas atmosphere, with voltages ranging from -0.5V to -2.0V. Following the attainment of electrochemical equilibrium, the efficiency of phosphorus removal was determined by quantitatively analyzing phosphorus content in the hot metal.The results demonstrated that applying external electric potentials significantly enhanced phosphorus removal rates compared to the chemical equilibrium between the molten slag and hot metal. Moreover, the influence of slag basicity on the efficiency of phosphorus removal during the electrolytic refining process was confirmed. Consequently, the correlation between slag basicity and phosphorus electrolytic refining efficiency was discussed in detail, based on the physicochemical and electrical properties of the slag.

Electrolytic Silver Recovery from Photovoltaic Waste

As an increasing number of photovoltaic (PV) systems reach end of life, there is a growing need to develop a process to keep critical materials in the supply chain. Currently, the processing cost of recycling solar panels exceeds the value of raw materials being collected. While there are many ways to approach this problem, one standout method is to improve silver recovery efforts. Silver, which is used as the fingers on the front contact, makes up less than 1% of the total mass of decommissioned systems while constituting approximately 40% of the value of the raw materials. Mechanical separation techniques have been generally successful in extracting the silver, but the product is still low in concentration and recyclers encounter significant processing fees from off takers. In this talk, a chemical leaching process in conjunction with an electrochemical recovery system will be discussed as a means of extracting high purity silver from recycled PV materials. Classically, electroplating processes utilize solutions containing metals at concentrations >10 g/L. In this case, the expected concentrations are less than 2 g/L, and maintaining high yields will require the electrochemical device to operate at concentrations on the order of 100s of ppm. Mass transport limitations will be mitigated by the development of a flow-through 3D cathode architecture, which will allow the system to operate at lower concentrations without requiring the application of higher cell potentials that would decrease selectivity and subsequently lower the purity of the recovered silver product. The performance of these devices will be explored in conjunction with auxiliary system components and controls that will be integrated to yield an automated system for silver powder recovery. Figure 1

Unveiling Complex Interfaces: A Methodological Approach for Accurate Apxps Data Acquisition of Polymer Electrolyte Membrane Electrolysis Devices

Electrochemical water splitting is a promising pathway for the production of green hydrogen as an alternative fuel, chemical feedstock and storage medium for renewables. Yet, the process is hindered by slow kinetics of the oxygen evolution reaction at the anode. Also, large scale implementation will require reduced loadings of expensive and rare platinum group metals and development of new materials. Making progress on rational design for OER catalysts requires effective characterization of the electrode-electrolyte interface where the chemistry takes place. Synchrotron-based x-ray photoelectron spectroscopy (XPS) offers a versatile way to obtain surface chemical and elemental characterization of such materials. The use of X-rays in the tender regime (~2-6 keV) allows for deeper probing than the conventional soft X-ray (< 2 keV) energies that are common for this technique. The photoelectrons generated from tender x-rays have enough energy to penetrate tens of nanometers through low-density components such as a layer of liquid or polymeric electrolyte, allowing access to interfaces in operando conditions. At Beamline 9.3.1 of the Advanced Light Source, we have developed a fully operational two-electrode system to study these membrane electrode assemblies under active water-splitting conditions.Accurate and representative data collection can involve a series of considerations and tests during acquisition. In this talk, I will explain our specific approach, which combines conventional and sub-second snapshot acquisition modes to minimize beam effects and test for phenomena that can contribute to erroneous interpretation of data. I will demonstrate the efficacy of this approach with results on a series of iridium-based polymer electrolyte membranes. With the application of elevated potential, we can correlate the iridium valency and surface species with the appearance of product traces in a mass spectrum.

(Invited) Boron-Doped Diamond Powder/Nanoparticle Materials for Electrochemical Applications

Heavily boron-doped diamond (BDD) electrode exhibits several excellent electrochemical properties such as wide potential window, low background current, as well as extreme physical and chemical stabilities. Based on these properties, the BDD electrodes are expected to be used for highly sensitive electrochemical sensors and highly efficient electrolytic electrodes. The BDD electrodes are usually prepared by depositing a polycrystalline BDD thin film on a conductive substrate such as silicon wafer, and thus are used as hard planar electrodes. Furthermore, the size of the BDD electrode also has a limit depending on the CVD apparatus. These situations limit the range of applications of BDD electrodes, despite their excellent electrochemical properties. With the aim of expanding the range of applications of BDD in the electrochemical field, we have developed BDD powder (BDDP). BDDP is a conductive diamond material, which is prepared by the deposition of a BDD layer on the surface of commercially available diamond powder. BDDP has advantages over BDD thin films, such as a larger specific surface area and the ability to create electrodes by applying ink on a substrate, and can be used for applications that have not been possible with BDD thin-film electrodes.1. BDDP-packed electrolysis flow cellBDDP-packed electrolysis flow cell was developed for application to an efficient electrolytic water treatment system. A cylinder equipped with a filter was filled with BDDP (particle size of 40-60 μm) and the packed bed served as an anode. Since the BDDPs are in contact with each other in the BDDP-packed bed, the entire BDDP-packed bed is considered to be electrically connected without a binder. On the other hand, the interparticle voids in the BDDP-packed bed form a network-like narrow channel, and the electrolyte passing through the channel can be treated efficiently. 0.1 M Na2SO4 containing 50 μM methylene blue as a model for polluted water was treated with the BDDP-packed electrolysis flow cell at a voltage of 5 V applied to the two-electrode system of BDDP-packed bed anode and Pt cathode. As a result, it was found that as the amount of BDDP loaded increased, the decomposition rate of MB increased. This suggested that the entire BDDP-packed bed functioned as an anode. Moreover, no deterioration in the decomposition rate was observed even when repeated electrolysis experiments were performed using the BDDP-packed electrolysis flow cell. Therefore, the BDDP-packed electrolysis flow cell is expected to be useful for efficient and durable electrolytic water treatment systems.2. Pt/BDDP and Pt/BDND for a durable PEFC cathode catalystsA major cause of deterioration of polymer electrolyte fuel cell (PEFC) cathode catalysts is corrosion of the catalyst support due to application of high potential during start-stop operations. Therefore, there is a need for the development of a catalyst support with excellent high potential resistance. In this study, we prepared Pt-supported BDDP (Pt/BDDP) as a durable cathode catalyst, and investigated its electrochemical properties and durability to high potentials. In the CV of Pt/BDDP with a BDDP size of 200 and 300 nm, redox peaks characteristics for Pt was observed, confirming that the BDDP functions as a conductive catalyst support. Durability tests using high potential cycling (+1.0–+1.5 V vs. NHE) showed that the electrochemically active surface area (ECA) retention rate during the test was greater for Pt/BDDP than for conventional Pt/C. Therefore, the BDDP is expected to be used for a catalyst support durable to high potential application. In addition, Pt-supported boron-doped nanodiamond (Pt/BDND) showed also superior high potential durability compared to Pt/C.