Search Results (3,024)

Voltage-gated sodium channels are central to electrical excitability, and Nav1.7 is a major therapeutic target implicated in pain disorders and sensory signaling. Within the channel pore, permeating Na⁺ ions experience dynamically fluctuating hydration and coordination environments that may influence local ion–protein interactions. Identifying chemically distinct coordination states from molecular dynamics (MD) simulations is an important prerequisite for future higher-level electronic structure investigations. In this study, we present a reproducible workflow for identifying and classifying Na⁺ hydration–coordination microstates in the Nav1.7 pore using explicit-solvent molecular dynamics simulations. A geometrically defined pore region was used to quantify pore hydration and Na⁺ inner-shell coordination based on a 3.2 Å Na–O distance criterion. Na⁺ configurations were classified according to ligand identity into water-only (W), mixed protein–water (PW), and protein-only (P) microstates. Analysis of a 2 ns proof-of-principle simulation revealed a persistently hydrated pore environment, with Na⁺ coordination dominated by water-rich states and a smaller but distinct population of protein-contact configurations. These observations demonstrate that local coordination environments are chemically heterogeneous and cannot be fully described by hydration number alone. Representative structures from each microstate class were extracted to provide candidate configurations for future quantum mechanical, Quantum Mechanics/Molecular Mechanics (QM/MM), or density functional theory investigations of ion–ligand interactions in confined pore environments. The present work establishes a transparent and reproducible microstate-selection framework and does not report quantum mechanical energies, free-energy landscapes, or converged microstate populations. More broadly, the workflow provides a practical strategy for reducing complex MD ensembles into chemically interpretable coordination states suitable for subsequent higher-level analysis. Full article

This study investigates the effect of sintering temperature on the hot-corrosion behavior of Ti-6Al-4V alloy in a molten salt environment. Samples were sintered at 800 °C, 900 °C, 1000 °C and 1100 °C, then exposed to the Na₂SO₄—25%NaCl for 300 h at 650 °C. The corrosion kinetics were evaluated by measuring the mass change in the specimens, and the results were correlated with their corresponding corrosion rates. The results show that the sintering temperature drives corrosion kinetics by influencing the sample density and grain size. The sample sintered at 900 °C shows a low corrosion rate due to its refined microstructure. This refined microstructure provides a high grain boundary density, which serves as a diffusion path and enables the formation of a dense, protective Al₂O₃–TiO₂ layer, as confirmed by XPS. In contrast, the sample sintered at 800 °C exhibits high porosity, resulting in an initial weight loss due to molten-salt penetration and evaporation of volatile metal chlorides. The samples sintered at 1000 °C and 1100 °C exhibit coarsened grains, leading to a thicker, brittle oxide layer and severe delamination, which in turn result in high corrosion rates. The results show that optimizing the sintering temperature to around 900 °C would enhance hot-corrosion resistance in salt-contaminated environments. Full article

Groundwater contamination by redox-sensitive elements (RSEs) such as arsenic (As), chromium (Cr), vanadium (V), and selenium (Se) pose a critical challenge in alluvial aquifers, where seasonal hydrological forcing drives dynamic hydrogeochemical and redox conditions. This study investigates the seasonal evolution of groundwater hydrogeochemistry and multi-metal behavior in shallow aquifers of the Mid-Gangetic Plain, India, with particular emphasis on the role of seasonal redox decoupling. Monsoon conditions were dominated by strongly reducing environments (ORP: −150 to −70 mV), predominantly Ca–Mg–SO₄ and Na–Cl type facies. Under these conditions, significant correlations among RSEs in particular (As–V, As–Se) indicated coupled mobilization governed by the reductive dissolution of Fe–Mn (oxyhydr)oxides. Monsoon groundwater also exhibited strong associations between RSEs and agronomic indicators (NO₃⁻, SO₄²⁻), suggesting the influence of recharge-mediated agricultural inputs on redox-sensitive geochemical processes. In contrast, post-monsoon conditions showed a clear transition to sub-oxic states (ORP up to +121 mV) and were dominated by Ca–Mg–HCO₃ facies, accompanied by substantial increases in bicarbonate (~372%), electrical conductivity (~62%), and total dissolved solids (~21%). Despite the partial oxidation of the aquifer system, redox-sensitive metals did not respond uniformly. Instead, inter-element correlations weakened or disappeared, indicating a transition from coupled to decoupled contaminant behavior. Arsenic concentrations increased up to 20.8 µgL⁻¹, whereas Cr and V displayed variable enrichment controlled by alkali-induced desorption and carbonate-mediated surface interactions. This transition reflects seasonal redox decoupling, whereby seasonal redox shifts lead to metal-specific rather than coordinated multi-metal behavior. We propose a Seasonal Redox Decoupling Framework (SRDF) to explain the shift from coupled reductive release during monsoon conditions to selective mobilization pathways in the post-monsoon period. These findings demonstrate that seasonal redox shifts control not only metal concentrations but also inter-element relationships, leading to metal-specific risk profiles. This underscores the need for seasonally adaptive monitoring and management strategies in hydrologically dynamic alluvial aquifers. Full article

Natural saline–alkaline soils are widespread in Central Asia, yet microbial responses to salinity gradients and ionic composition remain poorly resolved. We profiled bacterial communities (16S rRNA V3–V4, Illumina MiSeq) in 20 topsoil (0–20 cm) samples from four regions of Kazakhstan spanning non-saline to highly saline conditions. Soil chemistry included pH, total mineralization (dry residue), and major ions (Na⁺, Cl⁻, SO₄²⁻, HCO₃⁻, Ca²⁺, Mg²⁺, K⁺). Alpha (Chao1, Shannon, observed ASVs) and beta diversity (Bray–Curtis; ANOSIM; PCoA) were evaluated across salinity classes. Soils were alkaline (pH 7.91–10.47) and covered a broad salinity range (256–26,312 mg/L), driven mainly by Na⁺ with chloride and/or sulfate. Alpha diversity remained stable across salinity classes, though dispersion increased under high salinity. Community composition differed significantly among classes (ANOSIM R = 0.428, p = 0.005), with partial PCoA separation and overlap, indicating gradual turnover along the salinity gradient. In contrast, fungal communities showed no significant response to salinity, with stable alpha and beta diversity across all samples and consistent dominance of Ascomycota. Communities were dominated by Actinomycetota (formerly Actinobacteriota), Bacteroidota, and Pseudomonadota (formerly Proteobacteria). Bacteroidota increased in highly saline soils (FDR q = 0.036), whereas Acidobacteriota decreased (FDR q = 0.052). Thermodesulfobacteriota (formerly Desulfobacterota) correlated positively with sulfate, and Cyanobacteriota negatively with chloride. Overall, Kazakhstan’s saline–alkaline soils show stable bacterial alpha diversity but moderate, ion-linked compositional shifts with enrichment of halotolerant taxa. Full article

City-scale unmanned aerial vehicle vision-and-language navigation (UAV-VLN) requires accurate upstream target localization from an overhead map, onboard observation, and language description. Existing VLM-based methods often treat road names, landmarks, and spatial relations as raw text, leaving the model to search a large map and implicitly infer geometric constraints. This paper proposes GPOD, an inference-time candidate-prior interface for the upstream target-localization stage in city-scale UAV-VLN. GPOD converts language anchors, spatial relations, target-category cues, static map objects, and vehicle detections into ranked candidate priors through branch-specific candidate generation, thereby reformulating unconstrained full-map coordinate regression as candidate-prior-conditioned coordinate prediction. The static branch aligns language constraints with map-object geometries, while the dynamic branch uses YOLOv8l-VisDrone with Slicing Aided Hyper Inference (SAHI) to construct detection-conditioned vehicle candidates. In the GPOD-VLM setting, ranked candidates are injected as structured spatial prompts and the base VLM predicts the final continuous coordinates; GPOD-Direct is a candidate-direct diagnostic variant that directly uses candidate centers without VLM coordinate regression. On the CityNav localization protocol, GPOD improves FlightGPT Overall SR@20m from 15.23% to 25.61% and consistently reduces Mean Navigation Error (Mean NE) across splits and backbones. On Val-Unseen, GPOD-Direct (Top-1) reaches 32.59% SR@20m, showing that ranked candidate priors provide strong discrete localization signals. These results show that inference-time candidate priors can reduce city-scale search ambiguity without updating the base VLM parameters, while also revealing a candidate-utilization gap in the current prompt-based continuous coordinate-regression interface. Full article

In dynamic environments, Simultaneous Localization and Mapping (SLAM) systems often struggle with the challenges posed by moving objects. To address these issues, we propose Dynamic-Object-Elimination LiDAR-Visual-Inertial SLAM (DOE-LVI), an advanced tightly coupled LiDAR-Visual-Inertial SLAM system. DOE-LVI integrates two primary subsystems: the Visual-Inertial System (VIS) and the LiDAR-Inertial System (LIS). The VIS component extracts depth information from LiDAR scans and correlates it with visual features, providing accurate pose estimation by minimizing both visual and IMU residuals. The LIS uses this initial estimate to generate range images and perform preliminary removal of dynamic points. Misclassified points are then corrected through ground fitting and precise scan matching with the submap. For enhanced loop closure detection, DOE-LVI employs global LiDAR descriptors, which significantly improve both localization robustness and accuracy. Experimental evaluations on the KITTI and UrbanNav datasets demonstrate that DOE-LVI achieves robust localization and mapping performance, particularly in highly dynamic environments. Full article

Background: The study aims to compare the short-term clinical outcomes of transcatheter aortic valve implantation (TAVI) with the novel self-expandable, intra-annular Navitor valve (NAV) and the balloon-expandable, intra-annular Sapien 3 Ultra valve (S3U). Methods: From a single-center TAVI database, patients receiving NAV and S3U were identified. We applied 1:2 propensity score matching for the selected variables (gender, age, aortic valve perimeter, area, diameter, mean aortic valve gradient, EuroScore2, coronary artery disease (CAD), previous stroke and previous pacemaker implantation), resulting in 153 patients. Results: Clinical outcomes at 30 days of 51 patients with NAV [mean age: 80.4 ± 6.7 years; 51% female; mean annulus diameter: 24.1 ± 1.40 mm; EuroScore2: 3.4 ± 3.1%] and 102 patients with S3U [mean age: 79.9 ± 6.5 years (p = 0.7); 51% female (p > 0.99); mean annulus diameter: 24.1 ± 1.4 mm (p > 0.99); EuroScore2: 3.2 ± 2.7 (p = 0.7)] were analyzed according to VARC-3 recommendations. Post-TAVI aortic valve mean (S3U: 11.0 [3–27] mmHg; NAV: 7 [3–15] mmHg; p < 0.001) and maximum (S3U: 22 [6–44] mmHg; NAV: 12 [5–28] mmHg; p < 0.001) gradients at discharge were significantly lower with NAV, whereas the effective orifice area (EOA) of the aortic valve measured significantly larger with NAV (S3U: 1.5 [0.8–3.8] cm²; NAV: 2.1 [0.9–3.5] cm²; p < 0.001). Rates of no to mild paravalvular regurgitation (PVL) were 92.1% after NAV and 91.2% after S3U implantation (p = 0.15), mild to moderate PVL were 2.0% after NAV vs. 2.9% after S3U (p = 0.1) and moderate PVL were 2% after NAV and 1% after S3U (p = 0.07). None of the patients had a severe regurgitation. Severe patient–prosthesis mismatch (PPM) occurred significantly less with NAV (S3U: 14.7%; NAV: 7.8%; p = 0.002). One (1%) non-disabling stroke occurred within the S3U group and none occurred within the NAV group (p = 0.1). Life-threatening (S3U: 2.9%; NAV= 1%; p > 0.99) and major (S3U: n = 2.9; NAV: 0%; p = 0.55) bleeding events were comparable between both groups. The incidence of major (S3U: 2.9%; NAV: 2.0%; p > 0.99) vascular complications and the need for permanent pacemaker implantation (S3U: 9.8%; NAV: 11.8%; p = 0.8) were comparable in both groups. The 30-day mortality rate was 0.7% [1 in NAV group (2%), none in S3U; p = 0.3]. Conclusions: In conclusion, at 30-day follow-up, the self-expanding intra-annular Navitor valve demonstrated excellent acute safety and superior early hemodynamic performance, characterized by significantly lower transvalvular gradients and lower rates of severe PPM compared to the balloon-expandable Sapien 3 Ultra. However, whether these acute hemodynamic advantages translate into superior long-term clinical outcomes remains to be determined in long-term follow-up studies. Full article

Background/Objectives: Bone infection remains a severe clinical challenge characterized by recurrence, antimicrobial resistance, and high morbidity, driving the search for new therapeutic strategies. Despite advances in developing biomaterials with suitable biocompatibility, biodegradability, and structural properties, the lack of effective antibacterial activity continues to significantly limit the treatment of bone defects. To overcome this issue, we investigated the incorporation of silver-based nanostructures into calcium polyphosphate/alginate (CPP/Alg) matrices as an antibacterial reinforcement strategy for bone-related applications. Methods: Silver nanoparticles (AgNPs) were synthesized in aqueous medium via NaBH₄-mediated chemical reduction, using either alginate (Alg) or sodium polyphosphate (PP) as stabilizing agents, enabling a comparative evaluation of biocompatible polymer- and polyphosphate-stabilized systems. Subsequently, AgNPs were incorporated into calcium polyphosphate/alginate (CPP/Alg) matrices to obtain Ag-containing composites. Results: The AgNPs exhibited spherical morphology, Zeta potential values ranging from −38.7 ± 0.2 to −23 ± 0.3 mV, and hydrodynamic diameters between 25.2 ± 0.2 and 143 ± 5 nm. Structural characterization of the biocomposites by X-ray diffraction confirmed hydroxyapatite as the major crystalline phase, while Raman spectroscopy revealed vibrational bands corresponding to both the inorganic and polymeric components. SEM revealed a dense, rough surface, and ICP-OES analysis confirmed the presence of Ag. Antibacterial activity assays demonstrated effective growth inhibition of Staphylococcus aureus and Staphylococcus epidermidis, with inhibition halos growing with increasing composite dosage. Notably, antibacterial activity was achieved at relatively low Ag contents, underscoring the efficiency of these biocomposites. Conclusions: These findings confirm the effective incorporation of AgNPs into the CPP/Alg matrix and support the classification of composites as promising antibacterial biomaterials for bone regeneration applications. Full article

Hydrogen peroxide fuel cells have emerged as a promising class of electrochemical energy conversion device owing to the dual redox character of H₂O₂, its liquid-phase storage, and its ability to operate in air-free environments. In this work, a dual-compartment direct H₂O₂ fuel cell using a Prussian Blue cathode and a tantalum anode, separated by a Nafion 115 proton exchange membrane, was systematically characterized and optimized with respect to electrolyte pH and ionic composition. The influence of pH on OCV was investigated independently in each compartment across the range of pH 2 to 12. In the tantalum compartment, OCV increased non-linearly with pH from 573 mV to 808 mV, driven by the enhanced electrochemical reactivity of the system under alkaline conditions. In the Prussian Blue compartment, OCV decreased from 676 mV to 199 mV with increasing pH, reflecting the instability of the material in alkaline conditions. The effect of the electrolyte ionic composition on average current density was subsequently investigated by varying the concentrations of NaCl and Dy(NO₃)₃. Increasing NaCl from 0 to 2.5 M produced an increase in current density from 0.414 mA/cm² to 0.973 mA/cm², consistent with ohmic resistance reduction through improved ionic conductivity. The addition of Dy(NO₃)₃ produced a positive response with an optimal concentration of $0.05$ M, at which current density reached 1.08 mA/cm², before declining sharply. Under the fully optimized conditions, pH 12 in the tantalum compartment, pH 2 in the Prussian Blue compartment, 0.3 M H₂O₂, 2.0 M NaCl, and 0.05 M Dy(NO₃)₃, the cell produced an OCV of 724 mV and a peak power density of 0.283 mW/cm² at a current density of 0.8 mA/cm². These results demonstrate that meaningful electrochemical performance can be achieved in a dual-compartment H₂O₂ fuel cell without the use of precious metal catalysts and highlight electrolyte engineering as an effective strategy for improving cell output in this class of device. Full article

Zeolites, both natural (e.g., clinoptilolite) and synthetic (e.g., FAU, ZSM-5), provide robust, tunable platforms for the removal of air pollutants and process-stream contaminants via adsorption and catalysis. This author-led article integrates experimental and theoretical insights on the adsorption of odorous compounds and ammonia (NH₃) and the catalytic abatement of nitrogen oxides (NOx) and nitrous oxide (N₂O), highlighting how topology, acidity, and metal speciation jointly control performance. Representative theoretical results show that adsorption on Brønsted acid sites is significantly more favorable (≈−1.1 eV for NH₃ and −0.37 eV for acetaldehyde) than on Na⁺ sites (≈0.02 eV and 1.22 eV, respectively), demonstrating the critical role of acid site distribution in adsorption selectivity. We dissect structure–function relationships encompassing pore size and connectivity, Si/Al ratio, Brønsted/Lewis site distribution, hydrophilicity/hydrophobicity, and the role of water, with emphasis on hierarchical porosity to alleviate transport limitations. Metal exchange and surface functionalization are discussed as levers to tailor adsorption strength and redox activity, supported by density functional theory (DFT) analyses and reaction pathways. We propose practical design descriptors (acid strength metrics, metal nuclearity, and confinement factors) that enable faster iteration of zeolite architecture for targeted separations and reactions. Sustainability considerations include the use of abundant natural zeolites, low-energy regeneration, stability under humid, mixed-stream conditions that minimize pressure drop and waste. The article closes with a forward look at data-guided optimization to accelerate “engineering zeolites” for durable, selective, and energy-efficient clean-air and process-intensification applications. Full article

To address the issues of poor sustained-release behavior and limited long-term efficacy associated with conventional salt-storage materials, this study developed the epoxy-resin-encapsulated slow-release salt-storage filler to enhance both the engineering performance and the deicing/snow-melting capacity of salt-storage pavements. In this study, attapulgite was optimized and selected as the salt storage carrier through the adoption of pesticide coating technology and experimental testing, wherein a deicing salt blend with a CaCl₂ to NaCl mass ratio of 2:1 was loaded via a wet adsorption method. Subsequently, using dimethicone as the surface modifier, the optimal encapsulation process was determined to involve the dilution ratio of epoxy resin to cyclohexanone of 4:1 and the curing agent dosage of 30% by weight. The results indicated that the recommended content of the filler should not exceed 5%. The filler reduced the high-temperature stability and water stability of the mixture, while the low-temperature crack resistance first increased and then decreased, peaking at the 2% filler content with an improvement of 12.2%. The water stability was the most significantly affected by the filler content. Ice–snow melting performance tests demonstrated that the salt-storage mixture with 5% filler achieved the deicing rate of 56.35% at −5 °C, meeting the industry standard requirements. The self-prepared slow-release salt-storage filler exhibited superior long-term ice–snow melting performance to V-260, with the slow-release duration extended by 60%. The salt release process was divided into three distinct stages: rapid dissolution, stable release and slow dissolution. The 60 °C was determined as the optimal temperature for the accelerated immersion testing, which the accelerated test could effectively simulate the natural immersion process. Based on the prediction model established accordingly, the functional service life of snow-melting for this slow-release salt-storage asphalt pavement in northern area was estimated be approximately 4.07 years. The slow-release salt-storage filler fabricated in this work possesses both remarkable sustained-release behavior and deicing efficacy. The findings provide the technical foundation for the development of novel salt-storage pavement materials, performance characterization, and mechanistic analysis of snow-ice melting. Full article

This work targets efficient visible-light-driven hydrogen evolution by construction of a dendritic CdS-based photocatalytic system decorated with Pt-Ni bimetallic cocatalysts (CdS@PtNi). The dendritic CdS was synthesized via a hydrothermal method, followed by in situ deposition of Pt and Ni using NaBH₄ chemical reduction, with cocatalyst loading tuned between 2 and 5 wt%. Among them, C@PN4 (4 wt% total metal loading) demonstrated the best performance, with a bandgap of ~2.15 eV. XRD results show that the samples retain the hexagonal CdS phase without significant impurities. SEM/TEM and elemental mapping confirm uniform dispersion of Pt and Ni, forming intimate interfaces with CdS. XPS results reveal positive shifts in S 2p and Cd 3d binding energies, indicating that the bimetallic cocatalyst promotes electron transfer from CdS to the metals and enhances interfacial coupling. Photoelectrochemical analysis shows C@PN4 features enhanced absorption above 500 nm, significantly reduced PL, extended carrier lifetime, higher transient photocurrent, and lower charge-transfer resistance, suggesting greater efficiency in charge separation and transport. Band structure analysis reveals a negative shift of the conduction band to a more reductive potential. In photocatalytic tests, C@PN4 achieves an H₂ yield of 15.6 mmol g⁻¹ over 4 h (3.9 mmol g⁻¹ h⁻¹), with <5% activity loss after four cycles. AQY reaches 0.0483% at 420 nm, with a monochromatic photon-to-hydrogen conversion efficiency (MPH) of up to 2.01%. Mechanistically, the Pt/CdS Schottky junction drives directional electron extraction, while Ni likely synergistically optimizes interfacial electronic distribution and facilitates water activation/dissociation; together, they accelerate surface reaction kinetics and suppress photocorrosion, achieving efficient and stable hydrogen evolution with low noble metal loading. Full article

Honey is a natural food product which in traditional production represents a clear example of the “farm-to-table” principle, as it excludes any processing of the original product. This study proposes an analytical approach for determining 30 most frequently determined chemical elements (Ag, Al, As, B, Ba, Bi, Ca, Cd, Co, Cr, Cs, Cu, Ga, In, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Rb, S, Se, Sr, Te, V, and Zn) in honey, emphasizing the use of a relatively large sample mass to overcome sample heterogeneity and ensure accurate and reliable results. About 31 linden and 16 rapeseed honey samples from different Bulgarian regions were analyzed. Pollen analysis data showed that pollen content ranged from 30 to 78% for linden and 30 to 93% for rapeseed honey. The results identify a group of elements—K, Ca, Mg, Sr, and Rb—whose concentrations show statistically significant dependence on the floral origin and purity of the honey. Based on these findings, these elements are proposed as potential markers for identifying the botanical origin of honey. Furthermore, macronutrients and micronutrients (P, S, B, Cu, Fe, Mn, and Zn), which are generally subject to homeostatic regulation, as well as micro-elements (Al, As, Cd, Co, Cr, and Pb), which are more strongly influenced by environmental factors, showed limited discriminatory potential and no clear correlation with floral purity and botanical origin. Therefore, they should not be used as criteria when assessing the botanical origin of honey, but rather as indicators of environmental pollution and potential quality or safety concerns. Overall, the research contributes to improving the reliability of botanical classification of honey by combining robust analytical methodology with statistically validated elemental markers, while also distinguishing between natural compositional features and contamination-related signals. Full article

Salt tolerance is a key factor limiting coastal vegetation restoration. In backshore areas, foliage is frequently exposed to salt mist and wave splash, which severely constrains plant survival and restoration outcomes. While root salt tolerance under short-term stress has been widely studied, foliar salt tolerance remains poorly understood. Here, using a self-developed experimental apparatus, we investigated the salt tolerance mechanisms of the coastal shrub Volkameria inermis through a long-term (159-day) foliar salt stress experiment (0–3.0% NaCl), followed by a 64-day recovery period. Field suitability was also evaluated at different coastal locations in Quanzhou Bay, Fujian Province. The results show that: (1) trait plasticity (e.g., leaf thickening), resource redirection (e.g., reduced growth rate, and new bud emergence in unstressed parts), and strong recovery capacity together enhance V. inermis adaptation to long-term foliar salt stress; (2) V. inermis exhibits adaptability to salinity ≤2.0% and survival under 3.0% despite severe injury; (3) besides osmotic adjustment, proline accumulation helps alleviate oxidative damage; and (4) field data demonstrated that leaf thickness and leaf water content were significantly associated with distance from the sea and elevation, thereby validating the salt-adaptation strategies observed under controlled conditions. This study provides a novel methodological framework and practical insights for selecting salt-tolerant species in coastal restoration. Full article

Porous bilayer Ni–Co and sandwiched Ni–Co–Ni electrodes were fabricated by combining aqueous electrodeposition with high-temperature molten-salt Al deposition and subsequent electrochemical dissolution in NaCl–KCl–AlF₃ melt at 750 °C. The study aimed to determine how the initial layer architecture controls phase evolution, porous structure formation, and hydrogen evolution performance in alkaline media. SEM/EDS and XRD analyses showed that the two electrode designs followed different reaction pathways during molten-salt treatment. In the Ni–Co system, Al reacted predominantly with Co, leading mainly to Co–Al intermetallic formation and, after dissolution, to a highly open coral-like porous network. In contrast, the Ni–Co–Ni architecture promoted mainly Ni–Al phase formation and produced a more compact porous surface with a Ni-rich outer layer. Despite these morphological differences, both layered porous electrodes outperformed untreated Ni and porous Ni in 1 M NaOH. At −0.6 V vs. RHE, porous Ni–Co and NiCo–Ni reached current densities of −162 and −141 mA·cm⁻², respectively, compared with −87 mA·cm for porous Ni and −45 mA·cm for flat Ni. The Ni–Co–Ni sandwiched electrode showed the most favourable HER kinetics and benchmark performance, with the lowest Tafel slope (111 mV·dec) and the lowest potentials at −10 and −100 mA·cm (−0.132 and −0.556 V, respectively). These results demonstrate that the electrocatalytic response of molten-salt-derived porous Ni-based electrodes is governed not only by porosity development but also by the spatial arrangement of metallic layers prior to Al infiltration and dealloying. Full article