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Small (Weinheim An Der Bergstrasse,... Apr 2024Developing robust non-platinum electrocatalysts with multifunctional active sites for pH-universal hydrogen evolution reaction (HER) is crucial for scalable hydrogen...
Developing robust non-platinum electrocatalysts with multifunctional active sites for pH-universal hydrogen evolution reaction (HER) is crucial for scalable hydrogen production through electrochemical water splitting. Here ultra-small ruthenium-nickel alloy nanoparticles steadily anchored on reduced graphene oxide papers (Ru-Ni/rGOPs) as versatile electrocatalytic materials for acidic and alkaline HER are reported. These Ru-Ni alloy nanoparticles serve as pH self-adaptive electroactive species by making use of in situ surface reconstruction, where surface Ni atoms are hydroxylated to produce bifunctional active sites of Ru-Ni(OH) for alkaline HER, and selectively etched to form monometallic Ru active sites for acidic HER, respectively. Owing to the presence of Ru-Ni(OH) multi-site surface, which not only accelerates water dissociation to generate reactive hydrogen intermediates but also facilitates their recombination into hydrogen molecules, the self-supported RuNi/rGOP hybrid electrode only takes overpotential of as low as ≈106 mV to deliver current density of 1000 mA cm, and maintains exceptional stability for over 1000 h in 1 m KOH. While in 0.5 m HSO, the RuNi/rGOP hybrid electrode exhibits acidic HER catalytic behavior comparable to commercially available Pt/C catalyst due to the formation of monometallic Ru shell. These electrochemical behaviors outperform some of the best Ru-based catalysts and make it attractive alternative to Pt-based catalysts toward highly efficient HER.
PubMed: 38587968
DOI: 10.1002/smll.202311509 -
Recent Advances in Food, Nutrition &... Apr 2024Electronarcosis is the most commonly used stunning method for large animals, but its consequences in tilapia still need to be evaluated. The aim of the study was to...
INTRODUCTION
Electronarcosis is the most commonly used stunning method for large animals, but its consequences in tilapia still need to be evaluated. The aim of the study was to evaluate the application of electronarcosis in the pre-slaughter stunning of Nile tilapia (Oreochromis ni-loticus) and verify its effects on dynamic physiological balance and meat quality.
METHODS
Nile tilapia specimens, totaling 184, with an average weight of 247.08 37.04 g, were randomly distributed. Each fish was individually placed in a rectangular tank constituted by a voltage regulator and aluminum electrode. The behavior of the fish subjected to different expo-sure times (5, 10, 20, and 30 seconds) and electric currents (1.50, 3.00, 4.50, and 6.00 amperes) with alternating and continuous currents was evaluated. Subsequently, the quality of the chilled fillets was checked after slaughter over a period of 35 days. The longest stun time was achieved using an alternating current of 3.00, 4.50, and 6.00A for 30 seconds.
RESULTS
The fillet quality index (FQI) showed a high correlation with the storage time. In the first 15 days of storage, the fish stunned with different alternating currents maintained a higher MQI, meeting the meat quality standard when compared to fish slaughtered by ice stunning. The fish fillets obtained using different electrical currents showed a pH similar to the fish fillets stunned with ice.
CONCLUSION
Therefore, electronarcosis can be applied in the slaughter of tilapia using al-ternating current between three and six amps for 30 seconds, with euthanasia time of 37 and 46 seconds, ensuring safety in the slaughter procedures in the industry, the quality of the meat, and the well-being of the animal.
PubMed: 38584535
DOI: 10.2174/012772574X282761240314044845 -
Light, Science & Applications Apr 2024Laser wakefield acceleration, as an advanced accelerator concept, has attracted great attentions for its ultrahigh acceleration gradient and the capability to produce...
Laser wakefield acceleration, as an advanced accelerator concept, has attracted great attentions for its ultrahigh acceleration gradient and the capability to produce high brightness electron bunches. The three-dimensional (3D) density serves as an evaluation metric for the particle bunch quality and is intrinsically related to the applications of an accelerator. Despite its significance, this parameter has not been experimentally measured in the investigation of laser wakefield acceleration. We report on an electro-optic 3D snapshot of a laser wakefield electron bunch at a position outside the plasma. The 3D shape of the electron bunch was detected by simultaneously performing optical transition radiation imaging and electro-optic sampling. Detailed 3D structures to a few micrometer levels were reconstructed using a genetic algorithm. The electron bunch possessed a transverse size of less than 30 micrometers. The current profile shows a multi-peak structure. The main peak had a duration of < 10 fs and a peak current > 1 kA. The maximum electron 3D number density was ~ 9 × 10m . This research demonstrates a feasible way of 3D density monitoring on femtosecond kilo-ampere electron bunches, at any position of a beam transport line for relevant applications.
PubMed: 38584154
DOI: 10.1038/s41377-024-01440-2 -
Advanced Science (Weinheim,... Apr 2024Direct seawater splitting (DSS) offers an aspirational route toward green hydrogen (H) production but remains challenging when operating in a practically continuous...
Direct seawater splitting (DSS) offers an aspirational route toward green hydrogen (H) production but remains challenging when operating in a practically continuous manner, mainly due to the difficulty in establishing the water supply-consumption balance under the interference from impurity ions. A DSS system is reported for continuous ampere-level H production by coupling a dual-cation exchange membrane (CEM) three-compartment architecture with a circulatory electrolyte design. Monovalent-selective CEMs decouple the transmembrane water migration from interferences of Mg, Ca, and Cl ions while maintaining ionic neutrality during electrolysis; the self-loop concentrated alkaline electrolyte ensures the constant gradient of water chemical potential, allowing a specific water supply-consumption balance relationship in a seawater-electrolyte-H sequence to be built among an expanded current range. Even paired with commercialized Ni foams, this electrolyzer (model size: 2 × 2 cm) continuously produces H from flowing seawater with a rate of 7.5 mL min at an industrially relevant current of 1.0 A over 100 h. More importantly, the energy consumption can be further reduced by coupling more efficient NiMo/NiFe foams (≈6.2 kWh Nm H at 1.0 A), demonstrating the potential to further optimize the continuous DSS electrolyzer for practical applications.
PubMed: 38569463
DOI: 10.1002/advs.202401702 -
Small (Weinheim An Der Bergstrasse,... Apr 2024Industrial-level hydrogen production from the water electrolysis requires reducing the overpotential (η) as much as possible at high current density, which is closely...
Industrial-level hydrogen production from the water electrolysis requires reducing the overpotential (η) as much as possible at high current density, which is closely related to intrinsic activity of the electrocatalysts. Herein, A-site cation deficiency engineering is proposed to screen high-performance catalysts, demonstrating effective Pr LaBaCoO (P LBC) perovskites toward alkaline hydrogen evolution reaction (HER). Among all perovskite compositions, PrLaBaCoO (P0.4LBC) exhibits superior HER performance along with unique operating stability at large current densities (J = 500-2000 mA cm-2 geo). The overpotential of ≈636 mV is achieved in P0.4LBC at 2000 mA cm-2 geo, which outperforms commercial Pt/C benchmark (≈974 mV). Furthermore, the Tafel slope of P0.4LBC (34.1 mV dec) is close to that of Pt/C (35.6 mV dec), reflecting fast HER kinetics on the P0.4LBC catalyst. Combined with experimental and theoretical results, such catalytic activity may benefit from enhanced electrical conductivity, enlarged Co-O covalency, and decreased desorption energy of H species. This results highlight effective A-site cation-deficient strategy for promoting electrochemical properties of perovskites, highlighting potential water electrolysis at ampere-level current density.
PubMed: 38566543
DOI: 10.1002/smll.202400760 -
Small (Weinheim An Der Bergstrasse,... Mar 2024Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline...
Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline seawater electrolysis is the development of efficient and stable electrocatalysts to overcome the limitation of sluggish kinetics. Here, a 3D nanorod hybrid catalyst is reported, which comprises heterostructure MoO@NiMoO supported Ru nanoparticles (Ru/ MoO@NiMoO) with a size of ≈5 nm. Benefitting from the effect of strongly coupled interaction, Ru/MoO@NiMoO catalyst exhibits a remarkable alkaline seawater hydrogen evolution performance, featured by a low overpotential of 184 mV at a current density of 1.0 A cm, superior to commercial Pt/C (338 mV). Experimental observations demonstrate that the heterostructure MoO@NiMoO as an electron-accepting support makes the electron transfer from the Ru nanoparticles to MoO, and thereby implements the electron redistribution of Ru site. Mechanistic analysis elucidates that the electron redistribution of active Ru site enhances the ability of hydrogen desorption, thereby promoting alkaline seawater HER kinetics and finally leading to a satisfactory catalysis performance at ampere-level current density of alkaline seawater electrolysis.
PubMed: 38554022
DOI: 10.1002/smll.202311477 -
Scientific Reports Mar 2024Thirty-five women were included in a clinical study to characterize the volatile organic compounds (VOCs) emitted by the skin during exposure to psychological stress. An...
Thirty-five women were included in a clinical study to characterize the volatile organic compounds (VOCs) emitted by the skin during exposure to psychological stress. An original silicon-based polymeric phase was used for VOC sampling on the forehead before and after stress induction. Cognitive stress was induced using specialized software that included a chronometer for semantic and arithmetic tasks. Assessment of stress was monitored using a State-trait anxiety inventory questionnaire, analysis of participants' verbal expressions and clinical measurements. Identification and relative quantification of VOCs were performed by gas chromatography-mass spectrometry. Stress induction was validated by a significant increase in state-anxiety as indicated by the questionnaire, modifications in electrodermal activity measurements and the expression of stress verbatims. In parallel, a sebum production increase and a skin pH decrease were observed. A total of 198 VOCs with different potential sources were identified. They were categorized in 5 groups: probable cosmetic composition, VOCs produced by the body or its microbiota, environmental origin, and dietary intake. In our qualitative statistical approach, three VOCs were found to be correlated with stress induction and 14 compounds showed significance in the paired Wilcoxon test. Fatty-acyls derived from lipids were predominantly identified as well as ethylbenzenes.
Topics: Humans; Female; Volatile Organic Compounds; Gas Chromatography-Mass Spectrometry; Skin; Stress, Psychological; Air Pollutants; Environmental Monitoring
PubMed: 38538690
DOI: 10.1038/s41598-024-57967-2 -
Advanced Materials (Deerfield Beach,... Jun 2024The minimization of irreversible active lithium loss stands as a pivotal concern in rechargeable lithium batteries, particularly in the context of grid-storage...
The minimization of irreversible active lithium loss stands as a pivotal concern in rechargeable lithium batteries, particularly in the context of grid-storage applications, where achieving the utmost energy density over prolonged cycling is imperative to meet stringent demands, notably in terms of life cost. Departing from conventional methodologies advocating electrode prelithiation and/or electrolyte additives, a new paradigm is proposed here: the integration of a designer lithium reservoir (DLR) featuring lithium orthosilicate (LiSiO) and elemental sulfur. This approach concurrently addresses active lithium consumption through solid electrolyte interphase (SEI) formation and mitigates minor yet continuous parasitic reactions at the electrode/electrolyte interface during extended cycling. The remarkable synergy between the Li-ion conductive LiSiO and the SEI-favorable elemental sulfur enables customizable compensation kinetics for active lithium loss throughout continuous cycling. The introduction of a minute quantity of DLR (3 wt% LiSiO@S) yields outstanding cycling stability in a prototype pouch cell (graphite||LiFePO) with an ampere-hour-level capacity (≈2.3 Ah), demonstrating remarkable capacity retention (≈95%) even after 3000 cycles. This utilization of a DLR is poised to expedite the development of enduring lithium batteries for grid-storage applications and stimulate the design of practical, implantable rechargeable batteries based on related cell chemistries.
PubMed: 38506631
DOI: 10.1002/adma.202400707 -
Advanced Materials (Deerfield Beach,... Jun 2024The plastic waste issue has posed a series of formidable challenges for the ecological environment and human health. While conventional recycling strategies often lead...
The plastic waste issue has posed a series of formidable challenges for the ecological environment and human health. While conventional recycling strategies often lead to plastic down-cycling, the electrochemical strategy of recovering valuable monomers enables an ideal, circular plastic economy. Here a corrosion synthesized single atom Pt/Ni(OH) electrocatalyst with part-per-million noble Pt loading for highly efficient and selective upcycling of polyethylene terephthalate (PET) into valuable chemicals (potassium diformate and terephthalic acid) and green hydrogen is reported. Electro-oxidation of PET hydrolysate, ethylene glycol (EG), to formate is processed with high Faraday efficiency (FE) and selectivity (>90%) at the current density close to 1000 mA cm (1.444 V vs RHE). The in situ spectroscopy and density functional theory calculations provide insights into the mechanism and the understanding of the high efficiency. Remarkably, the electro-oxidation of EG at the ampere-level current density is also successfully illustrated by using a membrane-electrode assembly with high FEs to formate integrated with hydrogen production for 500 h of continuous operation. This process allows valuable chemical production at high space-time yield and is highly profitable (588-700 $ ton PET), showing an industrial perspective on single-atom catalysis of electrochemical plastic upcycling.
PubMed: 38504525
DOI: 10.1002/adma.202403234 -
RSC Advances Mar 2024Microbial fuel cells (MFCs) represent simple devices that harness the metabolic activities of microorganisms to produce electrical energy from diverse sources such as... (Review)
Review
Microbial fuel cells (MFCs) represent simple devices that harness the metabolic activities of microorganisms to produce electrical energy from diverse sources such as organic waste and sustainable biomass. Because of their unique advantage to generate sustainable energy, through the employment of biodegradable and repurposed waste materials, the development of MFCs has garnered considerable interest. Critical elements are typically the electrodes and separator. This mini-review article presents a critical assessment of nanofiber technology used as electrodes and separators in MFCs to enhance energy generation. In particular, the review highlights the application of nanofiber webs in each part of MFCs including anodes, cathodes, and membranes and their influence on energy generation. The role of nanofiber technology in this regard is then analysed in detail, focusing on improved electron transfer rate, enhanced biofilm formation, and enhanced durability and stability. In addition, the challenges and opportunities associated with integrating nanofibers into MFCs are discussed, along with suggestions for future research in this field. Significant developments in MFCs over the past decade have led to a several-fold increase in achievable power density, yet further improvements in performance and the exploration of cost-effective materials remain promising areas for further advancement. This review demonstrates the great promise of nanofiber-based electrodes and separators in future applications of MFCs.
PubMed: 38500621
DOI: 10.1039/d4ra00674g