High Reduction Potential Research Articles

‘Top 10’ policing as an alternative place-based strategy: responding to the overcomplication and underestimation of the law of crime concentration

ABSTRACT Recent trends in crime and place research emphasize a micro-level focus on the concentration, stability, and patrollability of crime hot spots. Empirical findings consistently suggest that hot spots are disproportionate in crime concentration, are time stable, and have high crime reduction potential for place-based interventions. Due to a growing literature on hot spot identification techniques, research may be overcomplicating and underestimating the degree to which these concepts manifest, creating unnecessary challenges to crime prevention strategies. The current study analyzes robbery in three cities to determine whether crime hot spot concentration, stability, and patrollability observed at different hot spot aggregations (1%, 0.1%, and the “Top 10”) have characteristics that make them amenable to more efficient crime-reduction initiatives at smaller aggregations. Collectively, current findings suggest that “Top 10” Policing, which focuses on just the 10 most criminogenic hot spots within an agency’s jurisdiction, could have a meaningful impact on overall crime rates.

The reducing effect of aglime onN2OandCO2emissions balance from an acidic soil: A study on intact soil cores

AbstractThe functioning of the nitrous oxide (N2O) reductase enzyme involved in the last step of denitrification is pH sensitive, with an optimum of 6.8. A solution to mitigate N2O emissions would be to bring soil pH close to neutrality by adding agricultural liming products (aglime). Nevertheless, the influence of aglime on the soil greenhouse gas (GHG) balance (CO2–N2O) is a subject of debate, particularly when considering the fate of the carbon (C) derived from carbonates. Our objective was to investigate the results of the effect of calcium carbonate (CaCO3) aglime on the CO2–N2O balance. Sixteen cylinders of undisturbed acidic soil were taken from a sandy loam profile and incubated at 20°C for 107 days in anaerobic conditions (water‐filled pore space >60%). Eight limed treatment cylinders received 1.45 g of aglime on the soil surface (2 t NV ha−1) and 0.08 g of N (100 kg of N ha−1). Eight control treatment cylinders received only 0.08 g of N. N2O and CO2fluxes were measured and converted into CO2equivalents to perform a GHG balance calculation. Furthermore, soil and leachate properties were measured. Aglime application triggered a reduction of N2O emissions, probably due to an increase in soil pH at the beginning of the experiment, which would have led to the N2O reductase activation. High ‐N content in the soil may inhibit the high N2O reduction potential in the limed treatment. CO2emissions were unexpectedly lower in the limed treatment. Aglime addition did not enhance C mineralisation, which may be explained by the possible stabilisation of soil organic carbon. A significant 11.3% reduction of GHG emissions was observed in the limed treatment. Overall, our results show that a strategy of liming acidic agricultural soil could be implemented for its potential in GHG mitigation. Nevertheless, future in‐depth research is necessary to better understand the fate of the C brought about by aglime.

Nanoheterostructure by Liquid Metal Sandwich-Based Interfacial Galvanic Replacement for Cancer Targeted Theranostics.

Nanoheterostructures with exquisite interface and heterostructure design find numerous applications in catalysis, plasmonics, electronics, and biomedicine. In the current study, series core-shell metal or metal oxide-based heterogeneous nanocomposite have been successfully fabricated by employing sandwiched liquid metal (LM) layer (i.e., LM oxide/LM/LM oxide) as interfacial galvanic replacement reaction environment. A self-limiting thin oxide layer, which would naturally occur at the metal-air interface under ambient conditions, could be readily delaminated onto the surface of core metal (Fe, Bi, carbonyl iron, Zn, Mo) or metal oxide (Fe3 O4 , Fe2 O3 , MoO3 , ZrO2 , TiO2 ) nano- or micro-particles by van der Waals (vdW) exfoliation. Further on, the sandwiched LM layer could be formed immediately and acted as the reaction site of galvanic replacement where metals (Au, Ag, and Cu) or metal oxide (MnO2 ) with higher reduction potential could be deposited as shell structure. Such strategy provides facile and versatile approaches to design and fabricate nanoheterostructures. As a model, nanocomposite of Fe@Sandwiched-GaIn-Au (Fe@SW-GaIn-Au) is constructed and their application in targeted magnetic resonance imaging (MRI) guided photothermal tumor ablation and chemodynamic therapy (CDT), as well as the enhanced radiotherapy(RT) against tumors, have been systematically investigated.

Single‐Atom Lithiophilic Sites Confined within Ordered Porous Carbon for Ultrastable Lithium Metal Anodes

Attributing to the high specific capacity and low electrochemical reduction potential, lithium (Li) metal is regarded as the most promising anode for high‐energy Li batteries. However, the growth of lithium dendrites and huge volume change seriously limit the development of lithium metal batteries. To overcome these challenges, an ordered mesoporous N‐doped carbon with lithiophilic single atoms is proposed to induce uniform nucleation and deposition of Li metal. Benefiting from the synergistic effects of interconnected three‐dimensional ordered mesoporous structures and abundant lithiophilic single‐atom sites, regulated local current density and rapid mass transfer can be achieved, leading to the uniform Li deposition with inhibition of dendrites and buffered volume expansion. As a result, the as‐fabricated anode exhibits a high CE of 99.8% for 200 cycles. A stable voltage hysteresis of 14 mV at 5 mA cm−2 could be maintained for more than 1330 h in the symmetric cell. Furthermore, the full cell coupled with commercial LiFePO4 exhibits high reversible capacity of 108 mAh g−1 and average Coulombic efficiency of 99.8% from 5th to 350th cycles at 1 C. The ordered mesoporous carbon host with abundant lithiophilic single‐atom sites delivers new inspirations into rational design of high‐performance Li metal anodes.

Stabilizing Oxidation State of SnO2 for Highly Selective CO2 Electroreduction to Formate at Large Current Densities

Even though electrocatalytic CO2 reduction reaction (CO2RR) to formate has made significant advances, achieving a high cell energy efficiency at industrial-level current densities is still a bottleneck for the large-scale application of this technology. SnO2 is a promising electrocatalyst for formate production but is restricted by the unstable oxidation state under high reduction potentials, causing catalyst reconstruction and inactivation. Herein, we present an atomic doping strategy (by Cu, Bi, or Pt) to trigger the emergence of oxygen vacancy in the SnO2 lattice and stabilize the oxidation state of SnO2 during CO2RR. As a result, the optimal Cu-incorporated SnO2 can keep a high formate Faradic efficiency of >80% and a cell energy efficiency of about 50–60% at a wide range of current densities up to 500 mA cm–2 in a commercial flow cell, surpassing most reported works. A set of in situ spectroscopy measurements and controlled electrochemical tests suggest that the oxygen vacancy, induced by the participation of Cu/Bi/Pt single atoms, holds the key to stabilizing SnO2 as well as promoting the adsorption of formate-related *OCHO reaction intermediate. A qualitative relationship between the oxygen vacancy concentration and CO2-to-formate conversion is constructed on a series of doped SnO2 catalysts.

Visible‐Light‐Induced N‐Heterocyclic Carbene‐Catalyzed Single Electron Reduction of Mono‐Fluoroarenes

AbstractFluoroarenes are abundant and readily available feedstocks. However, due to the high reduction potentials of mono‐fluoroarenes, their photoreduction remains a continuing challenge, motivating the development of efficient activation modes to address this issue. This report presents the blue light‐induced N‐heterocyclic carbene (NHC)‐catalyzed single electron reduction of mono‐fluoroarenes for biaryl cross‐couplings. We discovered that under blue light irradiation, NHC/tBuOK combination could construct powerful photoactive architectures to promote single electron transfer for Caryl−F bond reduction via forming highly reducing NHC radical anion. Notably, the strategy was also successful to reduce Caryl−O, Caryl−N, and Caryl−S bonds for biaryl cross‐couplings.

Visible-Light-Induced N-Heterocyclic Carbene-Catalyzed Single Electron Reduction of Mono-Fluoroarenes.

Fluoroarenes are abundant and readily available feedstocks. However, due to the high reduction potentials of mono-fluoroarenes, their photoreduction remains a continuing challenge, motivating the development of efficient activation modes to address this issue. This report presents the blue light-induced N-heterocyclic carbene (NHC)-catalyzed single electron reduction of mono-fluoroarenes for biaryl cross-couplings. We discovered that under blue light irradiation, NHC/tBuOK combination could construct powerful photoactive architectures to promote single electron transfer for Caryl -F bond reduction via forming highly reducing NHC radical anion. Notably, the strategy was also successful to reduce Caryl -O, Caryl -N, and Caryl -S bonds for biaryl cross-couplings.

Effectiveness of Inexpensive Cloth Facemasks and Their Amendments to Reduce Ambient Particulate Exposures: A Case of Kathmandu, Nepal.

Inexpensive cloth masks are widely used to reduce particulate exposures, but their use became ubiquitous after the outbreak of COVID-19. A custom experimental setup (semiactive at 5.1 m/s airflow rate) was fabricated to examine the efficiency of different types of commercial facemasks collected randomly from street vendors. The sample (N = 27) including (n = 16) cloth masks (CMs), (n = 7) surgical masks (SMs), and (n = 4) N95 filtering facepiece respirators (FFRs), of which SMs and N95 FFRs taken as a standard for efficiency comparison were all tested against ambient aerosols (PM2.5 and PM10 μg/m3). The prototype cloth masks (PTCMs) (N = 5) design was tailored, and their performance was assessed and compared with that of standard commercial masks. The filtering efficiency tested against ambient coarse particulates (PM10) ranged from (5% to 34%) for CMs with an average of 16%, (37% to 46%) for SMs with an average of 42%, (59% to 72%) for PTCMs with an average of 65%, and (70% to 75%) for N95 FFRs with an average of 71%, whereas against fine particulates (PM2.5), efficacy ranged from (4% to 29%) for CMs with an average of 13%, (34% to 44%) for SMs with an average of 39%, (53% to 68%) for PTCMs with an average of 60%, and (68% to 73%) for N95 FFRs with an average of 70%, respectively. The efficiency followed the order N95 FFRs > PTCMs > SMs > CMs showing poor exposure reduction potential in CMs and high exposure reduction potential in N95 FFRs and PTCMs. Amendment in existing CMs using eco-friendly cotton fabric with better facial adherence can protect human health from exposure to fine particulates <2.5 μm and can reduce the risk of micro-plastic pollution caused by polypropylene (PP) facemasks.

Insight into the reactions of antimonite with manganese oxides: Synergistic effects of Mn(III) and oxygen vacancies

Manganese oxides (MnxOy) are critical for determining the environmental behaviors and fate of antimonite (Sb(III)). However, little is known about the qualitative/quantitative connection between MnxOy structures and Sb(III) fate. Herein, the reactions of Sb(III) and six MnxOy with different structures were systematically investigated. The initial oxidation rates of Sb(III) (rinit) on six MnxOy decreased in the order of γ-MnO2>δ-MnO2>α-MnO2>γ-MnOOH>Mn3O4>β-MnO2 (pHinitial=7.0), from 0.32 ± 0.04 to 11.17 ± 1.61 mmol/min/mol-Mn. The amounts of antimony retained (i.e., the sum of Sb(III) and antimonate (Sb(V))) on these MnxOy followed the same trend as that of oxidation. Oxidation of Sb(III) released Mn(II) and created more sites for adsorption. Outwardly, MnxOy with higher reduction potential (E0) and specific surface area (SSA) favored faster Sb(III) oxidation. Inwardly, Mn(III) and oxygen vacancies (Ov) exhibited a synergistic effect on Sb(III) oxidation. Mn(III) can easier accept electron than Mn(IV) based on the change in Gibbs free energy calculation. Ov can adsorb free oxygen to form surface oxygen (Osur) which is much more reactive than lattice oxygen (Olatt). Moreover, Ov is in close proximity to Mn(III) in high-valent MnxOy which facilitated the reactions between Sb(III) and Mn(III) through the enhancement of Sb(III) adsorption and electron transfer. Ov in low-valent MnxOy is adjacent to Mn(II), thus it showed weaker enhancement than that in high-valent MnxOy. Part of δ-MnO2 and almost all Mn3O4 were converted to γ-MnOOH during their reaction with Sb(III), while the other four MnxOy were barely changed. The results obtained provide mechanistic insight into the reactions occurring within Sb(III) and MnxOy, which are helpful for better understanding and prediction of the fate of Sb(III) in Mn-rich environments.

Photosensitized Radical-Anion-Driven Metal-Free Selective Reduction of Aldehydes Using Graphene Oxide as an Electron Relay Mediator under Visible Light.

Despite the modern boost, developing a new photocatalytic system for the reduction of aldehydes is still challenging due to their high negative reduction potential. Herein, we have used a metal-free photoinduced electron-transfer system based on a cheap and readily available organic dye eosin Y (EY), graphene oxide (GO), and ammonium oxalate (AO) for photocatalytic reduction of structurally diverse aldehydes under sustainable conditions. The protocol shows remarkable selectivity for the photocatalytic reduction of aldehydes over ketones. The decisive interaction of GO and AO with the various states of EY (ground, singlet, triplet, and radical anions), which are responsible for the commencement of the reaction, was examined by various theoretical, optical, electrochemical, and photo-electrochemical studies. The synergetic system of GO, EY, and AO is appropriate for enhancing the separation efficiency of visible-light-induced charge carriers. GO nanosheets act as an electron reservoir to accept and transport photogenerated electrons from the photocatalytic system to the reactant. The reduction of the GO during the process ruled out the back transfer of photoexcited charges. Control experiments explained that the reaction involves two stages: electron transfer and protonation. This process eliminates the necessity of precious-metal-based photocatalysts or detrimental sacrificial agents and overcomes the redox potential limitations for the photoreduction of aldehydes.

Stable Zn–WO3 battery with a ZnCl2 water-in-salt electrolyte

Transition metal oxide, WO3, has shown great potential in zinc-ion rechargeable batteries as cathode material, yet the poor structural stability and low capacity significantly hindered its further application. Herein, a 30 m water-in-salt electrolyte (WiSE) was rationally designed to construct a stable Zn–WO3 battery. The relatively fewer free water molecules and lower desolvation barrier of [ZnCl4]2- ions in ZnCl2 WiSE not only resulted in a wide electrochemical stability window, low depth of discharge, high reduction potential but also contributed to the limited dissolution of WO3 and high electrochemical corrosion resistance. As a result, the assembled Zn–WO3 battery with 30 m ZnCl2 WiSE achieved a specific capacity of 94.8 mAh g−1 at 0.1 A g−1, energy density of 18.9 Wh kg−1 at a power density of 747.3 W kg−1 and capacitance retention of 94.8% after 1,000 cycles at a high rate of 1 A g−1. Furthermore, a flexible quasi-solid-state Zn–WO3 battery was fabricated using ZnCl2 WiSE without adding adhesives, demonstrating great potential for the next-generation energy storage application.

Promoted electron transfer in Fe2+/Fe3+ co-doped BiVO4/Ag3PO4 S-scheme heterojunction for efficient photo-Fenton oxidation of antibiotics

A Fe2+/Fe3+ co-doped BiVO4/Ag3PO4 S-scheme heterojunction catalyst was synthesized by a simple hydrothermal method and applied to achieve efficient photo-Fenton for antibiotics degradation (99.70 %). The co-doping of Fe3+/Fe2+ highlighted red shift of optical absorption edge (535–800 nm) and adjustable band structure of BiVO4/Ag3PO4. The collaborative system of photocatalytic and Fenton could maintain high catalytic activity and stability in the treat of simulated actual water and high efficiency within wide pH conditions (3–7). The degradation experiments were employed to show removal efficiency on tetracyclines and quinolones antibiotics including tetracycline (TC), ciprofloxacin (CIP), doxycycline (DO), levofloxacin (LEV), norfloxacin (NOR), and enrofloxacin (ENR). Mechanism exploration elaborated that the m-FBVO/APO composites with dominant Fe2+ preserved both high oxidation potential (<−0.33 eV vs NHE) and reduction potential (>2.45 eV vs NHE) through the constructed BiVO4/Ag3PO4 S-scheme heterojunction. Efficient e−/h+ pairs separation was further achieved through Fe3+/Fe2+ pairs cycling. And degradation pathway of TC was mainly investigated to verify its mineralization. This work provides a new sight towards catalytic mechanisms in heterogeneous photo-Fenton degradation systems.

The formation of sulfate-green rust through Fe(II) sorption to montmorillonite: Impacts on abiotic nitrate reduction

Green rust (GR) minerals are generally considered to be effective reductants of pollutants and the electron transfer from aqueous Fe(II) to structural Fe(III) in montmorillonite has recently been discovered to be a pathway to GR formation at pH ∼7.8. In this study, we have further delineated the pH conditions and examined the effect of aqueous sulfate concentrations that allow for the formation of sulfate-GR through this unique pathway. Iron(II) sorption experiments demonstrated that the amount of ‘sorbed’ Fe(II) on montmorillonite semi-quantitatively transformed into sulfate-GR at pH values ≥7.5 in the presence of environmentally-relevant sulfate concentrations (i.e., 10 mM). However, excess sulfate concentrations (100 mM) resulted in comparatively less Fe(II) sorption and sulfate-GR was only observed to form at pH 8. As such, it was concluded that the degree of Fe(II) sorption to montmorillonite is critical to GR formation when aqueous Fe(II) and montmorillonite co-exist. In contrast to sulfate-GR minerals formed through other pathways (e.g., co-precipitation of dissolved Fe(II) and Fe(III) species), this montmorillonite-synthesized GR was significantly less reactive towards nitrate reduction, with <2.5 % of 0.2 mM nitrate being reduced over a 6-day period. This behaviour was correlated to reduction potential and it was, therefore, concluded that the relatively high reduction potential that occurs in the presence of montmorillonite exerts a significant influence on the rate of nitrate reduction by sulfate-GR to the point that it may not be a competitive process to microbiological nitrate denitrification. As such, the environmental relevance of green rust to nitrate reduction cannot be inferred simply by its presence, but rather the reduction potential of the environmental system in which it is found.

Synthesis of cyclic carbonates from CO2 cycloaddition to bio-based epoxides and glycerol: an overview of recent development.

Anthropogenic carbon dioxide (CO2) emissions contribute significantly to global warming and deplete fossil carbon resources, prompting a shift to bio-based raw materials. The two main technologies for reducing CO2 emissions are capturing and either storing or utilizing it. However, while capture and storage have high reduction potential, they lack economic feasibility. Conversely, by utilizing the CO2 captured from streams and air to produce valuable products, it can become an asset and curb greenhouse gas effects. CO2 is a challenging C1-building block due to its high kinetic inertness and thermodynamic stability, requiring high temperature and pressure conditions and a reactive catalytic system. Nonetheless, cyclic carbonate production by reacting epoxides and CO2 is a promising green and sustainable chemistry reaction, with enormous potential applications as an electrolyte in lithium-ion batteries, a green solvent, and a monomer in polycarbonate production. This review focuses on the most recent developments in the synthesis of cyclic carbonates from glycerol and bio-based epoxides, as well as efficient methods for chemically transforming CO2 using flow chemistry and novel reactor designs.

Endovascular navigation with Fiber Optic RealShape technology.

Fiber Optic RealShape (FORS) technology has recently been introduced as an adjunctive guidance technology that allows real-time three-dimensional visualization of dedicated endovascular devices while avoiding radiation exposure. It consists of equipment which sends pulses of light through hair-thin optical fibers that run within a dedicated hydrophilic wire and selective catheters. The purpose of the study was to report the observed benefits and limitations related to the first edition of FORS technology. Data were collected prospectively from the first 50 patients undergoing FORS-guided endovascular repair at a single center between February 2020 and February 2021 as part of the global multicenter FORS Learn registry. All consecutive, elective procedures with one or more navigation tasks attempted with FORS were included. Factors related to FORS navigation task success were assessed. The time required for the catheterization of each task as well as the amount of radiation exposure (fluoroscopy time, dose area product, and estimated skin dose) were collected. A per-task analysis was conducted. End points included the success rate in achieving a stable FORS-guided catheterization, catheterization time, and radiation dose during catheterization. During the study period from February 2020 to February 2021, 50 patients were treated using FORS technology. Forty-five patients were treated for aortic aneurysm, 4 for iliac artery aneurysm, and 1 for splenic artery aneurysm. Overall, 201 navigation tasks were completed for these procedures and FORS was used in 186 tasks (92.5%). No FORS-related complication was recorded and a success rate of 60.2% (n= 116) was observed. Target vessel (TV) angle of 45° or greater, TV stenosis, and the renal arteries as navigation tasks (compared with celiac artery or superior mesenteric artery) were associated with a lower success rate. Catheterization of a TV through a branch more frequently required a standard catheter in combination with the FORS-enabled guidewire. Successful task catheterization using FORS guidance was associated with a shorter catheterization time 6minutes (interquartile range, 3-11minutes) versus 16minutes (interquartile range, 10-24minutes) (P< .001) and lower radiation exposure compared with unsuccessful catheterization (dose area product, 4.4cGy/cm2 vs 12.5cGy/cm2; P< .001). FORS technology was implemented successfully as a new guidance technology in a complex endovascular aortic repair program and was associated with an encouraging success rate and a high potential for radiation reduction.

Screening of Chromium-reducing Bacteria from Tannery Effluents

Tannery effluent has remained one of the major sources of chromium pollution in the environment. Although conventional methods have been widely used, they are inefficient and costly. Bacterial remediation is one of the best alternatives being proposed. Therefore, the aim of this research was to isolate bacteria from tannery effluents and screen them for chromium-reduction potentials. Three different tannery effluents were collected and used for the isolation of chromium-reducing bacteria. The organisms were identified using morphological and biochemical characteristics and screened on 1% (v/v) Cr (VI). The results revealed the presence of three bacterial species, namely: Bacillus subtilis, Escherichia coli and Pseudomonas sp. The screening results revealed that out of the three bacterial isolates, Bacillus subtilis had the highest reduction potential (86.23%), while equal reduction capacity was recorded in both E. coli and Pseudomonas sp. (84.03%). Therefore, these three isolates can be used as a consortium to improve biological remediation of Cr (VI) effluents.

New Synthetic Quinoline (Qui) Derivatives as Novel Antioxidants and Potential HSA's Antioxidant Activity Modulators-Spectroscopic Studies.

The antioxidant activity of drugs, as well as the influence of drugs on the activity of endogenous antioxidant mechanisms in the human body is of great importance for the course of the disease and the treatment process. Due to the need to search for new therapeutic methods, the study of newly synthesized substances with potential therapeutic activity is necessary. This study aimed to designate some properties and characteristic parameters of new, synthetic quinoline three derivatives-1-methyl-3-allylthio-4-(4'-methylphenylamino)quinolinium bromide (Qui1), 1-methyl-3-allylthio-4-(3'-hydroxyphenylamino)quinolinium bromide (Qui2) as well as 1-methyl-3-allylthio-4-(4'-hydroxyphenylamino)quinolinium bromide (Qui3), including their antioxidant properties, as well as to analyse their activity as the potential modulators of Human Serum Albumin (HSA) antioxidant activity. In order to achieve the goal of the study, spectroscopic methods such as UV-Vis and circular dichroism (CD) spectroscopy have been used and based on the obtained data only slight and probably some surface interaction of quinoline derivatives (Qui1-Qui3) with HSA have been observed. The effect of Qui1-Qui3 on the HSA secondary structure was also insignificant. All analysed quinine derivatives have antioxidant activity against ABTS cation radical, in turn against DPPH radical, only Qui3 has noticeable antioxidant potential. The highest reduction potential by Qui3 as well as (Qui3 + HSA)complex has been shown. Qui3 mixed with HSA has mostly the synergistic effect against DPPH, ABTS and FRAP, while Qui1 and Qui2 in the presence of HSA mostly have a synergistic and additive effect towards ABTS, respectively. Based on the obtained results it can be concluded that Qui2 and Qui3 can be considered potential modulators of HSA antioxidant activity.

A 3D Framework with Li3 N-Li2 S Solid Electrolyte Interphase and Fast Ion Transfer Channels for a Stabilized Lithium-Metal Anode.

The Li-metal anode has been recognized as the most promising anode for its high theoretical capacity and low reduction potential. However, the major drawbacks of Li metal, such as high reactivity and large volume expansion, can lead to dendrite growth and solid electrolyte interface (SEI) fracture. An in situ artificial inorganic SEI layer, consisting of lithium nitride and lithium sulfide, is herein reported to address the dendrite growth issues. Porous graphene oxide films are doped with sulfur and nitrogen (denoted as SNGO) to work as an effective lithium host. The SNGO film enables the in situ formation of an inorganic-rich SEI layer, which facilitates the transport of Li-ions, improves SEI mechanical strength, and avoids SEI fracture. In addition, COMSOL simulation results reveal that the microchannels fabricated by the 3D printing technique further shorten the Li-ion transfer pathways and homogenize heat and stress distribution in the batteries. As a result, the assembled anode shows low capacity fading of 0.1% per cycle at 2 C rate with the sulfur cathode. In addition, the high lithium utilization of the SNGO host enables the anode to provide a stable capacity at low negative/positive electrode ratios under 3 in LiS batteries.

Understanding the distribution of platinum group metals and gold in the process of copper-nickel slag depletion with gas mixtures

This paper describes the results of a study that looked at the distribution of platinum group metals (PGMs) (Pt, Pd, Rh, Ru, Ir) and Au between Cu &ndash; Ni &ndash; Fe bottom phase and dump slag as a result of pyrometallurgical depletion of slag, a by-product of oxidizing smelting of sulphide copper-nickel concentrate. The pyrometallurgical process was performed in a bubbling mode using reducing gas mixtures of various compositions. The consumption of reducing agent was found to be the key factor governing the output of the bottom phase and hence the chemical composition of the products. For the first time ever, the authors used the results of the chemical analysis of the products to calculate the distribution coefficients for PGMs and gold between the bottom phase versus the slag when the depletion process involved an intensive stirring of the melt. Thus, a variation range was established for the distribution coefficients of noble metals, as well as the threshold concentration of Fe in the melt. Once the latter has been reached, the distribution coefficients remain almost unchanged and the extraction of PGMs into dump slag is minimal. Using scanning electron microscopy and electron probe microanalysis, the authors established how many noble metals get carried away with dump slag. Proneness of Au to get dissolved in silicate melts was revealed, which is also typical of Cu. The conducted study helped establish that only 5% of Pt, Pd and Rh gets carried away with dump slag, which is the least loss. At the same time, about 10% of Ru and Ir goes into dump slag. The data reflecting the behavior of Au during slag depletion with reducing gas mixtures confirm that the maximum recovery of this metal from the slag would only be possible under a high reduction potential of the system. This corresponds to the minimum concentration of Fe in the bottom phase of 50% wt.

A Quasi‐Solid Electrolyte by In Situ Polymerization of Selective Solvent for Lithium‐Metal Batteries

AbstractLithium (Li) metal is a competitive anode material for rechargeable high energy density batteries due to its high specific capacity and low reduction potential. However, great challenges remain in addressing uncontrollable Li dendrite growth and unstable interface. Herein, we report a quasi‐solid electrolyte enabled by in situ polymerization of polyethylene glycol methyl ether acrylate. Meanwhile, a LiF‐enriched solid electrolyte interphase (SEI) is built on Li‐metal surface by function of the fluoroethylene carbonate additive. The SEI with a good mechanical stability prompts the dense and uniform Li deposition behavior. The in situ polymerized gel polymer electrolyte exhibits an ionic conductivity of 1.71×10−4 S cm−1 at 30 °C, and a considerable oxidative stability up to 4.5 V (vs. Li/Li+). The Li||Li symmetric cells delivers a long‐term cycle life over 1400 h and a low voltage hysteresis at 0.5 mA cm−2, 1 mAh cm−2. To be paired with a LiFePO4 positive electrode, the cell shows a high discharge capacity of 135.6 mAh g−1 and capacity retention of 92.7 % after 300 cycles. This work provides a reference for the practical development of quasi‐solid electrolyte for lithium‐metal battery.