Lattice confinement of large-radius cerium enables atomic-level electronic modulation for oxygen evolution reaction (OER) electrocatalysts in anion exchange membrane water electrolyzer (AEMWE) applications but remains challenging. Herein, a metallic salt solution quenching strategy achieves lattice-confined cerium doping in iron sulfide composite nanoflowers (Fe9S10/FeS). The ultrafast cooling generates abundant grain boundaries and lattice strain, which collectively reduce FeFe orbital overlap, narrow the Fe d-band width, and shift the d-band center upward. These electronic modifications consequently optimize the adsorption energetics of oxygen-containing intermediates on the pristine Fe9S10/FeS surface, mitigating their excessively strong binding. According to density functional theory (DFT) calculations, the energy barrier for the rate-determining step is reduced from 2.22 eV to 1.82 eV. Consequently, the cerium-doped iron sulfide catalyst (Ce-FeS-4th) exhibits a low overpotential of 274 mV at 10 mA cm-2 and a Tafel slope of 68 mV dec-1. An AEMWE using this anode achieves 1.0 A cm-2 at 2.48 V and operates stably for over 300 h. Overall, this work establishes quenching-induced lattice confinement as a versatile paradigm for d-band center engineering in advanced electrocatalysts.
Solar-driven interfacial evaporation is a promising route to sustainable seawater desalination. However, challenges remain in achieving the dual regulation of photothermal conversion and hydration network for efficient evaporation. Inspired by natural photosynthesis, this study introduces a porphyrin metal-organic framework (MOF) wood evaporator, which enables simultaneous water evaporation, photocatalysis, and thermoelectric conversion under solar irradiation. The porphyrin MOF, serving as a dual platform for photothermal and photocatalytic applications, is anchored onto wood via stable chemical bonds. Meanwhile, the active groups on the porphyrin MOF improve the hydration network by binding to water molecules. Structural reconstruction rearranges loose cellulose fibers, forming an interwoven micro/nanocellulose network within the wood. This provides additional coordination sites for MOF anchoring. The prepared evaporator achieves an evaporation rate of 2.91 kg m-2 h-1, a H2O2 generation rate of 14.2 mmol m-2 h-1, and an output voltage of 50.2 mV under 1 sun irradiation. Density functional theory (DFT) calculations confirm that MOF incorporation substantially enhances evaporator-water interactions, reducing the evaporation enthalpy. Life cycle assessment (LCA) indicates that the prepared evaporator exhibits lower environmental impacts across multiple categories compared with three conventional desalination technologies. This work offers a sustainable route for solar-driven water evaporation.
Two-dimensional layered vanadium-based oxides have garnered significant attention due to their multivalent electronic configurations, abundant surface-active sites, and exceptional photocatalytic stability. However, conventional layered architectures suffer from tight interfacial stacking, which impedes charge carrier mobility and limits visible-light absorption efficiency, thereby constraining further enhancement of catalytic performance. This study employed an ultrasonic-assisted intercalation strategy to precisely embed Keggin-type Al₁₃ ([Al13O4(OH)24(H2O)12]7+, the structure is represented by twelve AlO6 octahedra and one central AlO4 tetrahedron. These octahedra are interconnected via edge sharing and bonded to the central AlO4 unit through corner sharing.) into the interlayer framework of VOx (exfoliated V2O5, denoted as VOx), thereby establishing a multiscale synergistic regulation mechanism encompassing structural morphology, electronic states, and photophysical properties. Experimental evaluation of the photocatalytic oxidation activity toward benzyl alcohol demonstrated that the exfoliated two-dimensional nanosheets (VOx-Al13) exhibited remarkable catalytic efficiency with a conversion rate of 99.7% and over 99% product selectivity, outperforming VOx. Femtosecond transient absorption (fs-TA) spectroscopic analysis revealed a dominant internal charge separation (ICS) state with a prolonged lifetime of 1.5 ns in VOx-Al13, which significantly enhanced charge transfer efficiency and catalytic reactivity. This study not only provides an effective modification strategy paradigm for optimizing layered transition metal oxides but also establishes a robust theoretical and experimental foundation for developing cost-effective, high-performance visible-light-driven photocatalytic systems with environmental sustainability.
Constructing polyion complex (PIC) networks with dense electrostatic interactions is a well-established strategy to enhance the strength and toughness of hydrogels. However, for polyion combinations with weak association energy, the construction of robust hydrogel networks is typically challenging. In this work, a PIC hydrogel integrating electrostatic and hydrogen bonding interactions was fabricated by polymerizing acrylic acid (AA) and acrylamide (AM) in a partially deprotonated polyallylamine hydrochloride (DPAH) solution. Subsequent dehydration-rehydration treatment enabled densification of the network structure. It is revealed that the dehydration-rehydration process not only reinforces the ionic cross-linked network and significantly elevates the network's flow activation energy but also enhances the hydrogel's hydrophobicity via enhanced ion-pairing interactions. Conversely, hydrogen bonding interactions from the introduced amide groups disrupt the originally dense intermolecular electrostatic interactions and accelerate the relaxation kinetics of the polymeric network. After dehydration-rehydration treatment, the tensile strength of the hydrogel was enhanced by approximately 32-fold, reaching ∼10 MPa, and the fracture toughness was elevated from about 0.05 to ∼11.61 MJ m-3, demonstrating ideal toughening and strengthening effects. Owing to its superior anti-swelling property derived from the enhanced hydrophobicity, the hydrogel can be well applied as flexible sensors for real-time monitoring of underwater motion, exhibiting robust signal transmission stability. This work presents a facile and novel strategy to diversify high-performance PIC hydrogel systems, especially those with inherently weak association energy, thus providing a new perspective for the design of hydrogel platforms for underwater applications.
Efficient extraction of photogenerated electrons across the semiconductor/conductive-substrate interface is essential for photoelectrochemical (PEC) water oxidation, yet this interface is often less considered than bulk and surface charge-transfer processes. Herein, oxygen-vacancy-enriched ZnO nanorods (Ov-ZnO NRs) were grown on three-dimensionally ordered SnO2 inverse-opal skeletons to construct a hierarchical SnO2 IOs/Ov-ZnO photoanode. The interconnected SnO2 inverse opal simultaneously provides a conductive framework and enhances light harvesting through multiple scattering and slow-photon effects, while its crystallographic compatibility with the FTO substrate alleviates electron-transfer losses at the semiconductor/substrate interface. The one-dimensional Ov-ZnO NRs provide short carrier-transport pathways, a large electrode/electrolyte contact area, and defect-mediated active sites for water oxidation. The optimized photoanode delivered a photocurrent density of 1.13 mA cm-2 at 1.2 V vs. RHE, approximately 3.3 times that of the flat SnO2/ZnO NRs reference (0.34 mA cm-2), together with an applied-bias photon-to-current efficiency of 0.274% at 0.80 V vs. RHE. Its bulk charge-separation and surface charge-injection efficiencies reached 53.3% and 71%, respectively, at 1.2 V vs. RHE. Spectroscopic, electrochemical, and density functional theory analyses collectively indicate enhanced interfacial charge redistribution, lower charge-transfer resistance, and more favorable OER energetics. These results establish the coordinated engineering of the conductive substrate interface, photonic architecture, and oxygen-vacancy defects as an effective strategy for improving ZnO-based PEC photoanodes.
Flexible porous piezoresistive materials are promising for wearable pressure sensors because of their low modulus, high compressibility, and structural adaptability. Their practical performance, however, is constrained by a trade-off among sensitivity, operating range, and cycling durability. This trade-off is particularly acute in conductive networks near the percolation threshold, where large pressure-induced resistance changes are accompanied by contact instability during repeated deformation. Here, we fabricate a three-dimensional interconnected thermoplastic polyurethane/graphene/liquid metal (TPU/G/LM) porous composite by freeze-drying. Graphene forms the primary piezoresistive network, whereas LM serves as a deformable electrical bridge between neighboring graphene domains, thereby promoting reversible pathway reconstruction and stabilizing electrical contacts during compression. At 14 vol% LM, the sensor operates from 11.1 Pa to 300 kPa, reaches a sensitivity of 4.46 kPa-1 in the low-pressure regime, exhibits response and recovery times of approximately 1 and 4 ms, respectively, and maintains a stable response over 20,000 cycles at 100 kPa. Demonstrations of wearable motion monitoring and wireless thermal warning further illustrate the potential of LM-bridged graphene networks for broad-range, durable, and multifunctional sensing.
While the facet dependence of Cu catalysts in the electrocatalytic CO2 reduction reaction (e-CO2RR) is well-established, how particle size dictates product selectivity on identical crystal facets, a critical but underexplored dimension of structure-performance relationships, remains elusive. Herein, we demonstrate a non-monotonic size-dependent selectivity toward methane (CH4) using (111)-terminated Cu tetrahedra (Cutet) with uniform sizes of 20, 42, 55, and 64 nm. Among these, the 55 nm Cutet exhibits optimal CH4 selectivity, delivering a peak Faradaic efficiency (FECH4) of 53.6% at -1.0 V versus reversible hydrogen electrode (RHE), while suppressing the competing hydrogen evolution reaction (HER) to 12.3%. In situ spectroscopy and theoretical calculations reveal that this selectivity trend arises from an optimal synergy between edge sites and (111) facet sites. Specifically, edge sites promote CO2 adsorption and *COOH formation, whereas neighboring facet sites facilitate the key *CO → *CHO step. The 55 nm tetrahedron achieves an optimal edge-to-facet ratio that balances sufficient edge sites for CO2 activation against limited edge sites to suppress *H-induced HER, thereby maximizing the cooperative relay of *CO from edges to facets for selective CH4 production. This work establishes particle size as a key design strategy to engineer cooperative active sites on facet-defined nanocrystals, providing an alternative principle for rational catalyst design beyond facet control alone.
Tungsten disulfide is a promising anode material for lithium-ion batteries (LIBs) owing to its high theoretical capacity, natural abundance, and environmental benignity, but its practical implementation is constrained by sluggish charge-transfer kinetics, large cycling-induced volume variation, and rapid capacity fading. Herein, we report a synergistic heteroanion substitution and carbon confinement strategy to stabilize the electrode architecture by encapsulating selenium-substituted WSSe nanoparticles in nitrogen/phosphorus-codoped porous carbon nanofiber (WSSe@NP-CNF) via a polyoxometalate-derived electrospinning method. Combined in-situ/ex-situ characterizations and theoretical calculations reveal that the Se substitution modulates the electronic structure of WSSe, promotes charge redistribution, and lowers the kinetic barrier for lithium storage, whereas the interconnected porous carbon nanofiber network affords continuous Li+/electron transport channels and mechanically buffers structural evolution during repeated cycling. Benefiting from this dual regulation, the WSSe@NP-CNF anode delivers a high specific capacity of 822.3 mAh g-1 at 0.1 A g-1, superior rate capability of 379.9 mAh g-1 at 5 A g-1, and durable cycling durability with 90.1% capacity retention after 1000 cycles at 2 A g-1. Impressively, the assembled LiFePO4||WSSe@NP-CNF full cell exhibits exceptional long-term stability, maintaining 100% capacity retention over 2400 cycles at 1 A g-1. This work highlights a rational electrode-design strategy that integrates heteroanion-regulated reaction kinetics with conductive carbon confinement, offering a viable route toward high-performance transition-metal chalcogenide anodes for advanced LIBs.
Bi2O2Se is an emerging layered semiconductor with excellent charge-transport properties and environmental stability, making it a promising photocatalyst for environmental remediation. Herein, single-crystalline Bi2O2Se nanosheets with tunable oxygen-vacancy (OV) concentrations were successfully synthesized via a facile hydrothermal route followed by hydrogen annealing to optimize their intrinsic photocatalytic activity. The optimized sample (Bi2O2Se 600) exhibited markedly enhanced photocatalytic performance, achieving degradation efficiencies of 94.90% for Congo red (CR) within 40 min and 87.03% for tetracycline (TC) within 60 min, with corresponding degradation rate constants 23.6 and 3.3 times higher than those of pristine counterpart, respectively. Spectroscopic and electrochemical analyses demonstrated that OV engineering effectively enhanced charge-carrier dynamics by suppressing electron-hole recombination and promoting interfacial charge transfer. Radical-trapping experiments combined with electron paramagnetic resonance (EPR) measurements identified ·O2- as the dominant reactive species responsible for pollutant degradation. In addition, Bi2O2Se 600 maintained excellent photocatalytic activity across different water matrices and exhibited outstanding cycling stability. This work presents an effective strategy for combine single-crystal engineering with oxygen-vacancy regulation to optimize charge-carrier dynamics, providing new insights into the rational design of high-performance photocatalysts for environmental remediation.
The chlorine evolution reaction (CER) is pivotal for advancing the chlor-alkali industry, which is limited by the sluggish kinetics. Transition metal catalysts offer highly tunable electronic structures, where regulating the spin state of metal centers is crucial but challenging for enhancing CER performance. Herein, Fe-doped spinel oxides (Fe-Co3O4) were synthesized via a simple sol-gel method. The strategic incorporation of Fe ions introduces geometric confinement, which modulates octahedral distortion at the surface and thereby regulating the spin state of Co centers, ultimately optimizing CER activity and stability. Combined experimental and theoretical analyses reveal that Fe doping triggers a spin-state transition in Co ions from high-spin towards intermediate-spin or low-spin configurations. The enhanced electronic interaction between Co and Fe 3d orbitals in Fe-Co3O4 leads to superior CER selectivity compared to pure Co3O4, even under unfavorable conditions such as high pH and lower Cl- concentrations. Furthermore, Fe-Co3O4 nanocubes exhibit excellent durability, maintaining stable performance for over 50 h, which is significantly better than that of Co3O4. Theoretical calculations confirm that octahedral Co and Fe sites in Fe-Co3O4 serve as the active centers for chloride ion release, in contrast to the tetrahedral Co sites in pristine Co3O4. The spin state modulation of Co not only facilitates chloride ion adsorption but also optimizes the adsorption energetics, elucidating the fundamental mechanism behind the enhanced CER activity. This work highlights the critical role of spin-state regulation at active sites and proposes a chitosan gel-mediated cross-linking strategy for fabricating high-performance CER catalysts.
HYPOTHESIS:Recent experiments have shown that tuning the initial wetting state of a hydrophobic surface before boiling gives rise to bubble behavior resembling that on hydrophilic surfaces. This contrasts with typical bubble behavior on hydrophobic surfaces, where bubble growth initiates from a residual vapor seed and results in slow growth and delayed departure. Here, we hypothesize that such wetting-state tuning modifies the near-surface liquid-vapor interfacial structure beneath the bubble, possibly through the formation of a near-surface thin liquid film, thereby altering bubble dynamics on hydrophobic surfaces. METHODS:Synchrotron X-ray imaging with high spatial resolution (2.44 μm) and a large field of view (∼5 × 5 mm) was employed in pool boiling experiments to visualize the near-surface liquid-vapor interface and bubble evolution under different surface initial wetting states. Non-dimensional analysis of bubble growth and departure was performed to characterize bubble dynamics. FINDINGS:We identify a unique bubble mode on the PDMS-coated hydrophobic surface in which the near-surface liquid-vapor interfacial structure resembles that on hydrophilic surfaces, suggesting the possible presence of a near-surface thin liquid film. In addition, the associated non-dimensional parameters indicate rapid bubble growth similar to that observed during microlayer evaporation-assisted growth on hydrophilic surfaces. Notably, the bubble departs rapidly and smoothly, maintaining an oblate shape and a nearly constant apparent contact angle during departure without obvious hysteresis. A capillary relaxation timescale defined from bubble-shape deformation is comparable to the actual departure duration, suggesting that capillary forces contribute significantly to the rapid bubble departure.
Chronic wounds present significant challenges due to persistent inflammation and exudate accumulation. Inspired by nature's sophisticated fluid-manipulation architectures, an integrated Janus micro/nanofibrous dressing for synergistic unidirectional exudate management and real-time colorimetric infection monitoring was developed. This smart dressing integrates a pH-responsive hydrophilic viscose outer layer with a hydrophobic polyurethane nanofibrous inner layer. By covalently immobilizing pH-sensitive dyes onto the viscose fibers, a leach-proof chromatic response "biological traffic light" that visually monitors wound status was achieved. The structural and wettability gradients within the Janus architecture generate a localized Laplace pressure difference, enabling autonomous, unidirectional exudate transport to prevent maceration. Beyond superior fluidic control, the smart dressing provides a non-invasive diagnostic window by exhibiting distinct color shifts in response to pH variations. Furthermore, the smart dressing maintains an optimal healing microenvironment through excellent air/vapor permeability, mechanical integrity, and cytocompatibility. In vivo evaluations confirm that this Janus dressing significantly accelerates tissue regeneration. This bioinspired sense-and-treat dressing offers a sophisticated strategy for the next generation of intelligent chronic wound care.
HYPOTHESIS:Surface pressure-area isotherms of Langmuir monolayers encode phase boundaries, molecular packing, coexistence regimes, and elastic response, but their interpretation is still often based on heterogeneous workflows that rely on subjective manual segmentation, noise-sensitive numerical derivatives, and limited uncertainty quantification. A phase-resolved, thermodynamically constrained equation-of-state framework can extract physically interpretable descriptors from quasi-equilibrium monolayer isotherms while keeping model complexity under statistical control. EXPERIMENTS:We introduce the Phase-Resolved Interfacial Surface Model (PRISM), a continuous surface equation of state for surface tension (or surface pressure) as a function of area per molecule. PRISM describes single-phase branches and first-order coexistence regions, enforces continuity at transition points, and activates an effective domain-corrected coexistence term only when statistically justified. Parameters are inferred by constrained nonlinear regression and accompanied by subsampling-based confidence intervals. FINDINGS:PRISM replaces subjective heuristics with objective inference, yielding limiting molecular areas, phase boundaries, coexistence descriptors, and elastic moduli with uncertainty quantification. Applied to DPPC, POPE, POPC, and POPS monolayers, the framework captures both sharp plateaus and sloped coexistence regions, reconstructs phase diagrams, and enables the estimation of phase-transition enthalpies and entropies when temperature-dependent coexistence data are available. The method is intended for quasi-equilibrium isotherms with distinguishable branches or effective first-order coexistence regimes; strongly hysteretic, collapse-dominated, or continuous-transition cases require additional treatment. A web application implementing PRISM is available at https://surffitter.simbioslab.com/ to apply the model to user-provided isotherms.
Intensive global agricultural growth has increased pesticide use, raising concerns about water contamination. Paraquat (PQ), a highly water-soluble, nonselective herbicide used in over 130 countries, poses serious risks to human health because its high solubility and long environmental half-life make it a persistent pollutant. Although conventional analytical methods provide excellent sensitivity, they require expensive instruments and complex sample preparation, limiting their practicality for on-site applications. Here, we present a fast, visual, on-site paraquat detection strategy based on smart liquid foam systems. The method exploits a highly selective host-guest complex between water soluble pillar[5]arene (WS-P[5]A) and PQ. First, WS-P[5]A hosts are loaded with the bio-based surfactant sucrose laurate (SL), which interacts less with WS-P[5]A than PQ. Secondly, PQ is added which replaces SL due to the higher binding constant between WS-P[5]A and PQ. Upon replacement of SL by PQ, surfactant is released which enables foam generation by hand-shaking. Changes in foam height correlate with PQ concentration, providing an intuitive visual readout. We demonstrate a high selective method even in the presence of competing contaminants, and we validate its performance across multiple water types. This supramolecular foam sensor could offer a simple, selective, rapid, and low-cost approach for the preliminary detection of paraquat in contaminated water. The proposed foam-based method is designed as an on-site screening tool that can be used by virtually anyone without specialized equipment, technical expertise, or laboratory infrastructure. Foam formation provides a straightforward visual indication of the presence of paraquat, enabling fast field-based assessment. If paraquat is detected qualitatively, quantification can subsequently be performed using well-established analytical techniques.
