Revitalizing Oxygen Reduction Reactivity of Composite Oxide Electrodes via Electrochemically Deposited PrOx Nanocatalysts.

Solid oxide fuel cells that operate at intermediate temperatures require efficient catalysts to enhance the inherently poor electrochemical activity of the composite electrodes. Here, a simple and practical electrochemical deposition method is presented for fabricating a PrOx overlayer on lanthanum strontium manganite-yttria-stabilized zirconia (LSM-YSZ) composite electrodes. The method requires less than four minutes for completion and can be carried out under at ambient temperature and pressure. Crucially, the treatment significantly improves the electrode's performance without requiring heat treatment or other supplementary processes. The PrOx-coated LSM-YSZ electrode exhibits an 89% decrease in polarization resistance at 650 °C (compared to an untreated electrode), maintaining a tenfold reduction after ≈400 h. Transmission line model analysis using impedance spectra confirms how PrOx coating improved the oxygen reduction reaction activity. Further, tests with anode-supported single cells reveal an outstanding peak power density compared to those of other LSM-YSZ-based cathodes (e.g., 418 mW cm-2 at 650 °C). Furthermore, it is demonstrated that multicomponent coating, such as (Pr,Ce)Ox, can also be obtained with this method. Overall, the observations offer a promising route for the development of high-performance solid oxide fuel cells.

Dual-Photosensitizer Synergy Empowers Ambient Light Photoactivation of Indium Oxide for High-Performance NO2 Sensing.

Light-activated chemiresistors offer a powerful approach to achieving lower-temperature gas sensing with unprecedented sensitivities. However, an incomplete understanding of how photoexcited charge carriers enhance sensitivity obstructs the rational design of high-performance sensors, impeding the practical utilization under commonly accessible light sources instead of ultraviolet or higher-energy sources. Here, a rational approach is presented to modulate the electronic properties of the parent metal oxide phase, exemplified by this model system of Bi-doped In2 O3 nanofibers decorated with Au nanoparticles (NPs) that exhibit superior NO2 sensing performance. Bi doping introduces mid-gap energy levels into In2 O3 , promoting photoactivation even under visible blue light. Additionally, green-absorbing plasmonic Au NPs facilitate electron transfer across the heterojunction, extending the photoactive region toward the green light. It is revealed that the direct involvement of photogenerated charge carriers in gas adsorption and desorption processes is pivotal for enhancing gas sensing performance. Owing to the synergistic interplay between the Bi dopants and the Au NPs, the Au-Bix In2-x O3 (x = 0.04) sensing layers attain impressive response values (Rg /Ra  = 104 at 0.6 ppm NO2 ) under green light illumination and demonstrate practical viability through evaluation under simulated mixed-light conditions, all of which significantly outperforms previously reported visible light-activated NO2 sensors.

Re-evaluation of battery-grade lithium purity toward sustainable batteries.

Recently, the cost of lithium-ion batteries has risen as the price of lithium raw materials has soared and fluctuated. Notably, the highest cost of lithium production comes from the impurity elimination process to satisfy the battery-grade purity of over 99.5%. Consequently, re-evaluating the impact of purity becomes imperative for affordable lithium-ion batteries. In this study, we unveil that a 1% Mg impurity in the lithium precursor proves beneficial for both the lithium production process and the electrochemical performance of resulting cathodes. This is attributed to the increased nucleation seeds and unexpected site-selective doping effects. Moreover, when extended to an industrial scale, low-grade lithium is found to reduce production costs and CO2 emissions by up to 19.4% and 9.0%, respectively. This work offers valuable insights into the genuine sustainability of lithium-ion batteries.

Simultaneous Performance and Stability Enhancement in Intermediate Temperature Solid Oxide Fuel Cells by Powder-Atomic Layer Deposited LSCF@ZrO2 Cathodes.

Employing porous structures is essential in high-performance electrochemical energy devices. However, obtaining uniform functional coatings on high-tortuosity structures can be challenging, even with specialized processes such as atomic layer deposition (ALD). Herein, a novel method for achieving a porous composite electrode for solid oxide fuel cells by coating La0.6 Sr0.4 Co0.2 Fe0.8 O3 -δ (LSCF) powders with ZrO2 using a powder ALD process is presented. Unlike conventional ALD, powder ALD can be used to fabricate extremely uniform coatings on porous electrodes with a thickness of tens of micrometers. The powder ALD ZrO2 coating is found to effectively suppress chemical degradation of the LSCF electrodes. The cell with the powder ALD coated cathode shows a 2.2 times higher maximum power density and 60% lower thermal degradation in activation resistance than the bare LSCF cathode cell at 700-750 °C. The result demonstrated in this study is expected to have significant implications for high-performance and durable electrodes in energy conversion/storage devices.

Maximizing Photoelectrochemical Performance in Metal-Oxide Hybrid Composites via Amorphous Exsolution-A New Exsolution Mechanism for Heterogeneous Catalysis.

Exsolution generates metal nanoparticles anchored within crystalline oxide supports, ensuring efficient exposure, uniform dispersion, and strong nanoparticle-perovskite interactions. Increased doping level in the perovskite is essential for further enhancing performance in renewable energy applications; however, this is constrained by limited surface exsolution, structural instability, and sluggish charge transfer. Here, hybrid composites are fabricated by vacuum-annealing a solution containing SrTiO3 photoanode and Co cocatalyst precursors for photoelectrochemical water-splitting. In situ transmission electron microscopy identifies uniform, high-density Co particles exsolving from amorphous SrTiO3 films, followed by film-crystallization at elevated temperatures. This unique process extracts entire Co dopants with complete structural stability, even at Co doping levels exceeding 30%, and upon air exposure, the Co particles embedded in the film oxidize to CoO, forming a Schottky junction at the interface. These conditions maximize photoelectrochemical activity and stability, surpassing those achieved by Co post-deposition and Co exsolution from crystalline oxides. Theoretical calculations demonstrate in the amorphous state, dopant─O bonds become weaker while Ti─O bonds remain strong, promoting selective exsolution. As expected from the calculations, nearly all of the 30% Fe dopants exsolve from SrTiO3 in an H2 environment, despite the strong Fe─O bond's low exsolution tendency. These analyses unravel the mechanisms driving the amorphous exsolution.

Effect of diabetes mellitus on the outcomes of total ankle arthroplasty: is controlled diabetes mellitus a risk factor?

BACKGROUND: It is still uncertain whether diabetes mellitus (DM) is a risk factor for poor outcomes and increased complications after total ankle arthroplasty (TAA). The objective of this study was to compare clinical outcomes and complication rates of TAA in patients with and without DM. METHODS: This study enrolled patients with symptomatic end-stage ankle osteoarthritis with a minimum follow-up period of 24 months after TAA. A total of 252 patients (266 ankles) were classified into two groups according to the presence of DM: (1) DM group (59 patients, 67 ankles) and (2) non-DM group (193 patients, 199 ankles). We defined controlled diabetes as (1) HbA1c level < 7.0%, or (2) fasting glucose level < 130 mg/dL with HbA1c level ≥ 7.0% for hospitalization period. Clinical outcomes data (Ankle Osteoarthritis Scale, American Orthopedic Foot and Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, and visual analog scale for pain) were compared preoperatively and at the final follow-up between the two groups. Complications following TAA were also compared between the two groups. RESULTS: All clinical variables had improved in both groups by the final follow-up (mean follow-up = 77.8 months). There was no significant difference in any clinical variable between the two groups at the final follow-up (P > 0.05). Of the 266 ankles, 73 ankles (19 in the DM group, 54 in the non-DM group) developed periprosthetic osteolysis. Although the DM group showed a higher prevalence of aseptic loosening or subsidence, the difference between the two groups was not statistically significant (P = 0.236). CONCLUSIONS: In the intermediate-term follow-up, TAA in patients with controlled DM showed clinical outcomes and complication rates comparable to patients without DM. Our results suggest that TAA can be done safely in diabetic patients if the DM is controlled in the perioperative period. LEVEL OF EVIDENCE: Therapeutic Level III.

Conductance stable and mechanically durable bi-layer EGaIn composite-coated stretchable fiber for 1D bioelectronics.

Deformable semi-solid liquid metal particles (LMP) have emerged as a promising substitute for rigid conductive fillers due to their excellent electrical properties and stable conductance under strain. However, achieving a compact and robust coating of LMP on fibers remains a persistent challenge, mainly due to the incompatibility of conventional coating techniques with LMP. Additionally, the limited durability and absence of initial electrical conductivity of LMP restrict their widespread application. In this study, we propose a solution process that robustly and compactly assembles mechanically durable and initially conductive LMP on fibers. Specifically, we present a shearing-based deposition of polymer-attached LMP followed by additional coating with CNT-attached LMP to create bi-layer LMP composite with exceptional durability, electrical conductivity, stretchability, and biocompatibility on various fibers. The versatility and reliability of this manufacturing strategy for 1D electronics are demonstrated through the development of sewn electrical circuits, smart clothes, stretchable biointerfaced fiber, and multifunctional fiber probes.

Rapid Joule Heating Synthesis of Oxide-Socketed High-Entropy Alloy Nanoparticles as CO2 Conversion Catalysts.

The unorthodox surface chemistry of high-entropy alloy nanoparticles (HEA-NPs), with numerous interelemental synergies, helps catalyze a variety of essential chemical processes, such as the conversion of CO2 to CO, as a sustainable path to environmental remediation. However, the risk of agglomeration and phase separation in HEA-NPs during high-temperature operations are lasting issues that impede their practical viability. Herein, we present HEA-NP catalysts that are tightly sunk in an oxide overlayer for promoting the catalytic conversion of CO2 with exceptional stability and performance. We demonstrated the controlled formation of conformal oxide overlayers on carbon nanofiber surfaces via a simple sol-gel method, which facilitated a large uptake of metal precursor ions and helped to decrease the reaction temperature required for nanoparticle formation. During the rapid thermal shock synthesis process, the oxide overlayer would also impede nanoparticle growth, resulting in uniformly distributed small HEA-NPs (2.37 ± 0.78 nm). Moreover, these HEA-NPs were firmly socketed in the reducible oxide overlayer, enabling an ultrastable catalytic performance involving >50% CO2 conversion with >97% selectivity to CO for >300 h without extensive agglomeration. Altogether, we establish the rational design principles for the thermal shock synthesis of high-entropy alloy nanoparticles and offer a helpful mechanistic perspective on how the oxide overlayer impacts the nanoparticle synthesis behavior, providing a general platform for the designed synthesis of ultrastable and high-performance catalysts that could be utilized for various industrially and environmentally relevant chemical processes.

Ex-Solution Hybrids Functionalized on Oxide Nanofibers for Highly Active and Durable Catalytic Materials.

Ex-solution catalysts containing spontaneously formed metal nanoparticles socketed on the surface of reservoir oxides have recently been employed in various research fields including catalysis and sensing, due to the process efficiency and outstanding chemical/thermal stability. However, since the ex-solution process accompanies harsh reduction heat treatment, during which many oxides undergo phase decomposition, it restricts material selection and further advancement. Herein, we propose an elaborate design principle to uniformly functionalize ex-solution catalysts at porous oxide frameworks via an electrospinning process. As a case study, we selected the ex-solved La0.6Ca0.4Fe0.95Co0.05-xNixO3-δ (x = 0, 0.025 and 0.05) and SnO2 nanofibers as ex-solution hybrids and main frameworks, respectively. We confirmed superior dimethyl sulfide (C2H6S) gas sensing characteristics with excellent long-cycling stability. In particular, the high catalytic activities of ex-solved CoNiFe ternary nanoparticles, strongly socketed on reservoir oxide, accelerate the spillover process of O2 to dramatically enhance the response toward sulfuric analytes with exceptional tolerance. Altogether, our contribution represents an important stepping-stone to a rational design of ex-solved particle-reservoir oxide hybrids functionalized on porous oxide scaffolds for a variety of applications.

Synthesis of Highly Tunable Alloy Nanocatalyst through Heterogeneous Doping Method.

The combination of supported metal nanoparticles and functional host oxides catalyze many major industrial reactions. However, uniform dispersion and ideal chemical configuration of such nanoparticles, which determines the catalytic activity, are often difficult to achieve. In this study, a unique combination is proposed of heterogeneous doping and ex-solution for the fabrication of Pt-Ni alloy nanoparticles on CeO2 . By manipulating the reducing conditions, both the particle size and composition are precisely controlled, thereby achieving a highly dispersed and stable alloy nanocatalyst. The unique behavior of controlled alloy composition is elucidated through classical diffusion and precipitation kinetics with elemental analysis of the grain boundaries. Finally, Pt-Ni alloy nanocatalysts are successfully tuned showcasing a breakthrough performance compared to single element catalyst in reverse water gas shift reaction with superior stability and reproducibility.

Dynamic Surface Evolution of Metal Oxides for Autonomous Adaptation to Catalytic Reaction Environments.

Metal oxides possessing distinctive physical/chemical properties due to different crystal structures and stoichiometries play a pivotal role in numerous current technologies, especially heterogeneous catalysis for production/conversion of high-valued chemicals and energy. To date, many researchers have investigated the effect of the structure and composition of these materials on their reactivity to various chemical and electrochemical reactions. However, metal oxide surfaces evolve from their initial form under dynamic reaction conditions due to the autonomous behaviors of the constituent atoms to adapt to the surrounding environment. Such nanoscale surface phenomena complicate reaction mechanisms and material properties, interrupting the clarification of the origin of functionality variations in reaction environments. In this review, the current findings on the spontaneous surface reorganization of metal oxides during reactions are categorized into three types: 1) the appearance of nano-sized second phase from oxides, 2) the (partial) encapsulation of oxide atoms toward supported metal surfaces, and 3) the oxide surface reconstruction with selective cation leaching in aqueous solution. Then their effects on each reaction are summarized in terms of activity and stability, providing novel insight for those who design metal-oxide-based catalytic materials.

Relationship between chronotype and depressive symptoms among newly hired hospital nurses in the Republic of Korea.

Background: This study was conducted to examine the relationship between chronotype and depressive symptoms to provide grounded knowledge in establishing nurses' health promotion strategies. Methods: The subjects of this study were 493 newly hired nurses working in 2 general hospitals within the university from September 2018 to September 2020. Sociodemographic and work-related characteristics were collected from a medical examination database and a self-reported questionnaire. These included sex, age, marital status, living situation, education level, alcohol consumption, physical activity, prior work experience before 3 months, workplace, and departments. To analyze the associations between the chronotype and depressive symptoms, multiple logistic regression analyses were performed to calculate odds ratios (ORs). Results: Among participants, 9.1% had depressive symptoms and 16.4% had insomnia. The subjects are divided into morningness (30.2%), intermediate (48.7%), and eveningness (21.1%). The multiple logistic regression analysis controlling for age, living status, education level, alcohol consumption, physical activity, workplace, prior work experience before 3 months, and insomnia, revealed that the OR of depressive symptoms in the eveningness group was 3.71 (95% confidence interval [CI]: 1.50-9.18) compared to the morningness group, and the R2 value was 0.151. It also can be confirmed that insomnia symptoms have a statistically significant effect on depressive symptoms (OR: 2.16, 95% CI: 1.03-4.52). Conclusions: Our findings suggest that evening-type nurses are more likely to have depression than morning-type nurses. We should consider interventions in a high-risk group such as the evening type nurses to reduce depressive symptoms in nurses.

Comparison between simultaneous bilateral total hip arthroplasty with and without drainage: A retrospective cohort study.

Simultaneous bilateral total hip arthroplasty (SBTHA) is an effective procedure for patients with disease bilaterally. But there is concern about increased blood loss and complications of SBTHA than staged total hip arthroplasty (THA). This study aimed to evaluate the differences in the clinical outcomes and complication rate of SBTHA with drainage and without drainage for reducing the concerns. Between October 2015 and April 2019, a retrospective cohort study was conducted with modified minimally invasive 2-incision method and a consecutive series of 41 SBTHA performed with drainage (Group I) were compared to 37 SBTHA performed without drainage (Group II). It was assessed clinically and radiographically for a mean of 2.1 ± 0.8 years (range, 1.0-4.8 years). Postoperative hematologic values (Hgb loss, total blood loss, transfusion rate), pain susceptibility, functional outcome (Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index score) and complication were compared in the drained group and the non-drained group. Postoperative Hgb loss (I: 2163.2 ± 698.7 g, II: 1730.4 ± 572.5 g; P = .002), total blood loss (I: 1528.8 ± 421.7 mL, II: 1237.6 ± 325.9 mL; P = .001) and mean transfusion unit (I: 0.7 ± 1.0 IU, II: 0.1 ± 0.3 IU; P < .001) were significantly lower in the without drainage group than in the with drainage group. But the morphine equivalent (I: 132.7 ± 314.1 mg, II: 732.2 ± 591.5 mg; P < .001) was significantly larger in the without drainage group. No significant difference was found between the drainage group and without drainage group in Harris Hip Score and Western Ontario and McMaster Universities Osteoarthritis Index score at final follow-up. SBTHA without drainage can reduce postoperative blood loss and the requirement for transfusion without increasing other complication. But SBTHA without drainage is more painful method than SBTHA with drainage. Therefore, SBTHA without drainage will be a good option to reduce the burden on the patient by reducing postoperative bleeding if it can control pain well after surgery. III, Retrospective case-control study.

Ni-Doped CuO Nanoarrays Activate Urea Adsorption and Stabilizes Reaction Intermediates to Achieve High-Performance Urea Oxidation Catalysts.

Urea oxidation reaction (UOR) with a low equilibrium potential offers a promising route to replace the oxygen evolution reaction for energy-saving hydrogen generation. However, the overpotential of the UOR is still high due to the complicated 6e- transfer process and adsorption/desorption of intermediate products. Herein, utilizing a cation exchange strategy, Ni-doped CuO nanoarrays grown on 3D Cu foam are synthesized. Notably, Ni-CuO NAs/CF requires a low potential of 1.366 V versus a reversible hydrogen electrode to drive a current density of 100 mA cm-2 , outperforming various benchmark electrocatalysts and maintaining robust stability in alkaline media. Theoretical and experimental studies reveal that Ni as the driving force center can effectively enhance the urea adsorption and stabilize CO*/NH* intermediates toward the UOR. These findings suggest a new direction for constructing nanostructures and modulating electronic structures, ultimately developing promising Cu-based electrode catalysts.

Nanoscale interface engineering for solid oxide fuel cells using atomic layer deposition.

Atomic layer deposition (ALD), which is already actively used in the semiconductor industry, has been in the spotlight in various energy fields, such as batteries and fuel cells, given its unique ability to enable the nanoscale deposition of diverse materials with a variety of compositions onto complex 3D structures. In particular, with regard to ceramic fuel cells, ALD has attracted attention because it facilitates the manufacturing of thin and dense electrolytes. Furthermore, recently, electrode surfaces and electrode/electrolyte interface modification are arising as new research strategies to fabricate robust fuel cells. In this mini-review, we present a brief overview of ALD and recent studies that utilize ALD in ceramic fuel cells, such as manufacturing thin film electrolytes, stabilizing electrodes, functionalizing electrodes, and modifying the chemistry of electrode surfaces. We also propose research directions to expand the utility and functionality of the ALD techniques.

Nanofiber Composites as Highly Active and Robust Anodes for Direct-Hydrocarbon Solid Oxide Fuel Cells.

Direct utilization of methane fuels in solid oxide fuel cells (SOFCs) is a key technology to realize the immediate inclusion of such high-efficiency fuel cells into the current electricity generation infrastructure. However, the broad commercialization of direct-methane fueled SOFCs is critically hindered by the inadequate electrode activity and their poor longevity, which primarily stems from the carbon build-up issues. To make the technology more competitive, a novel electrode structure that can dramatically improve the tolerance against coking is essential. Herein, we present highly active and robust core-shell nanofiber anodes, La0.75Sr0.25Cr0.5Mn0.5O3@Sm0.2Ce0.8O1.9 (LSCM@SDC), directly obtained with a single-nozzle electrospinning process through the use of two immiscible polymers. The intimate coverage of SDC on LSCM not only increases the active reaction sites but also promotes resistance toward carbon deposition and thermal aggregation. As such, the electrode polarization resistance obtained with LSCM@SDC NFs is among the lowest value ever reported with LSCM derivatives (∼0.11 Ω cm2 in wet H2 at 800 °C). The facile fabrication process of such complex heterostructures developed in this work is attractive for the design of not only SOFC electrodes but also other solid-state devices such as electrolysis cells, membrane reformers, and protonic cells.

Bimetallic Exsolved Heterostructures of Controlled Composition with Tunable Catalytic Properties.

In this paper, we show how the composition of bimetallic Fe-Ni exsolution can be controlled by the nature and concentration of oxygen vacancies in the parental matrix and how this is used to modify the performance of CO2-assisted ethane conversion. Mesoporous A-site-deficient La0.4Sr0.6-αTi0.6Fe0.35Ni0.05O3±Î´ (0 ≤ α ≤ 0.2) perovskites with substantial specific surface area (>40 m2/g) enabled fast exsolution kinetics (T < 500 °C, t < 1 h) of bimetallic Fe-Ni nanoparticles of increasing size (3-10 nm). Through the application of a multitechnique approach we found that the A-site deficiency determined the concentration of oxygen vacancies associated with iron, which controlled the Fe reduction. Instead of homogeneous bimetallic nanoparticles, the increasing Fe fraction from 37 to 57% led to the emergence of bimodal Fe/Ni3Fe systems. Catalytic tests showed superior stability of our catalysts with respect to commercial Ni/Al2O3. Ethane reforming was found to be the favored pathway, but an increase in selectivity toward ethane dehydrogenation occurred for the systems with a low metallic Fe fraction. The chance to control the reduction and growth processes of bimetallic exsolution offers interesting prospects for the design of advanced catalysts based on bimodal nanoparticle heterostructures.

Promoting Ex-Solution from Metal-Organic-Framework-Mediated Oxide Scaffolds for Highly Active and Robust Catalysts.

Ex-solution catalysts, in which a host oxide is decorated with confined metallic nanoparticles, have exhibited breakthrough activity in various catalytic reactions. However, catalysts prepared by conventional ex-solution processes are limited by the low surface area of host oxides, the limited solubility of dopants, and the incomplete conversion of doped cations into metal catalysts. Here, the design of the host oxide structure is reconceptualized using a metal-organic framework (MOF) as an oxide precursor that can absorb a large quantity of ions while also promoting ex-solution at low temperatures (400-500 °C). The MOF-derived metal oxide host can readily incorporate metal cations, from which catalytic nanoparticles can be uniformly ex-solved owing to the short diffusion length in the nano-sized oxides. The distinct ex-solution behaviors of Pt, Pd, and Rh, and their bimetallic combinations are investigated. The MOF-driven mesoporous ZnO particles functionalized with PdPt catalysts ex-solved at 500 °C show benchmark-level of acetone oxidation activity as well as acetone-sensing characteristics by accelerating both oxygen chemisorption and acetone dissociation. Their findings provide a new route for the preparation of highly active catalysts by engineering the architecture and composition of the host oxide to facilitate the ex-solution process rationally.

Hierarchical Structure of CuO Nanowires Decorated with Ni(OH)2 Supported on Cu Foam for Hydrogen Production via Urea Electrocatalysis.

Owing to the low theoretical potential of the urea oxidation reaction (UOR), urea electrolysis is an energy-saving technique for the generation of hydrogen. Herein, a hierarchical structure of CuO nanowires decorated with nickel hydroxide supported on 3D Cu foam is constructed. Combined theoretical and experimental analyses demonstrate the high reactivity and selectivity of CuO and Ni(OH)2 toward the UOR instead of the oxygen evolution reaction. The hierarchical structure creates a synergistic effect between the two highly active sites, enabling an exceptional UOR activity with a record low potential of 1.334 V (vs the reversible hydrogen electrode) to reach 100 mA cm-2 and a low Tafel slope of 14 mV dec-1 in 1 m KOH and 0.5 m urea electrolyte. Assembling full urea electrolysis driven by this developed UOR electrocatalyst as the anode and a commercial Pt/C electrocatalyst as the cathode provides a current density of 20 mA cm-2 at a cell voltage of ≈1.36 V with promising operational stability for at least 150 h. This work not only enriches the UOR material family but also significantly advances energy-saving hydrogen production.