ABSTRACT Metal–organic frameworks (MOFs) are promising materials for thermochemical energy storage, yet the role of the flexibility of the framework in governing water adsorption and transport is not adequately understood at the atomistic level. In this work, we employ quantum assisted neural network‐based molecular dynamics simulations (DeepMD) to systematically investigate the water uptake, adsorption enthalpies, diffusion coefficients, and structural correlations of a hydrophilic MOF (ZIF‐90) with both rigid and flexible frameworks. The simulated results showed that the flexible ZIF‐90 exhibits a nearly constant heat of adsorption between –46 and –64 kJ/mol in a wide water loading range (4, 8, 16, 25 and 40 per unit cell), in good agreement with the experimental findings, whereas the rigid framework shows a sharp variation. Similarly, diffusion analysis consistently reveals higher water mobility in the flexible framework, particularly at low and intermediate loadings. The radial distribution functions for key atom pairs (Zn–Ow, O–Hw, O–Ow) show excellent agreement with previous experimental and computational reports, which further validates our simulations. Overall, these findings provide molecular‐level insights into the interplay between framework flexibility, adsorption energetics, and transport properties, offering guidance for the rational design of porous materials for thermal energy storage applications.
ABSTRACT Platinum‐group‐metal‐free catalysts represent a necessary economic choice for industrial‐scale anion exchange membrane (AEM) electrolyzers. A three‐dimensional binder‐free spinel Ni 1 − x Fe x Co 2 O 4 (x = 0.1–0.4) electrocatalyst is synthesized directly on nickel felt via a urea‐mediated sono‐hydrothermal method. The nanorod‐shaped morphology is chosen to reduce mass‐transfer limitations while maintaining catalyst activity. NiFeCo‐2 (20% Fe) offers the optimal balance of iron content, lattice modification, homogeneous nanorod coverage, and surface area, showing the best oxygen evolution reaction (OER) activity, giving 282 mV overpotential at 10 mA cm − 2 and 53 mV dec − 1 Tafel slope. As the anode in an anion exchange membrane water electrolyzer (AEMWE), NiFeCo‐2 reaches 1.748 V at 1 A cm − 2 , 1.92 V at 2 A cm − 2 , and 2.09 V at 4 A cm − 2 in wet cathode mode, and sustains stable operation through two 72‐h accelerated stress test sequences under both wet and dry cathode feeding. Operation starting in dry cathode mode shows better performance retention than in wet mode. Post‐test electron microscopy and textural analysis confirm that the nanorod catalyst layer remains largely preserved, indicating that the observed voltage increase is consistent with resistance growth rather than catalyst loss. These results highlight binder‐free Ni 1 − x Fe x Co 2 O 4 as a promising, affordable anode for AEM water electrolysis.
ABSTRACT MXenes, as emerging multifunctional nanomaterials, have attracted the attention of the scientific community in recent years for environmental remediation, including adsorptive cleanup of radio‐contaminants due to their important characteristic profile, such as large surface area and structural diversity. Thus, this study aims to review MXenes as functional nanosorbents for the adsorptive elimination of radio‐contaminants from simulated radio‐wastewater. The goal was to explore research advances, identify trends, provide critical insights, highlight challenges, and underscore interesting future research hotspots. Notably, it was discovered that MXenes have an adsorption capacity of 7.76–1376.75 mg/g, with functionalized MXenes taking the lead, while the number of active sites plays a key role. Furthermore, the key mechanisms governing the adsorption operation were complexation/chelation/coordination, chemisorption, ion exchange, and electrostatic interaction. Overfitting of isotherm and kinetics models was suspected. Findings from cyclic stability studies (reusability up to 2–8 times) and the effect of co‐existing pollutants further showed that MXenes have potential for practical uses. Lastly, challenges, research gaps, and potential avenues for further study were discussed. The review work led to an inference that MXene‐based adsorption techniques can eco‐efficiently remove radio‐pollutants from water and nuclear wastewater if given adequate attention.
ABSTRACT The environmental concerns associated with plastic and fluorocarbon‐based materials have driven the search for sustainable options, particularly in the development of highly water‐repellent coatings. Plant‐based materials offer a promising solution due to their biodegradability and sustainability. In this study, we developed highly water‐repellent coatings using treated pine and palm pollen. Superhydrophobicity was achieved by integrating a hydrophobic plant‐based wax with a micro‐scale rough structure formed by the pollen. To enhance their surface chemistry, the two pollen species underwent acid treatment, which effectively removed proteins and altered the wettability of the sporopollenin‐based structures. The modified pollen was then combined with two plant‐based waxes, carnauba and soybean, to fabricate the final coatings. The resulting surfaces demonstrated remarkable water repellence, achieving the highest water contact angles of ∼158° and sliding angles of <6° with the pine pollen/carnauba wax formulations. In contrast, the palm pollen/carnauba wax formulations achieved the highest water contact angle of ∼151° and sliding angle of 13°. Furthermore, this study investigates the influence of both broken and unbroken pollen structures on coating performance. These results demonstrate the potential of plant‐derived materials as environmentally friendly alternatives for water‐repellent coating applications.
ABSTRACT Multi‐absorber III–V semiconductors represent the state of the art in high‐efficiency solar‐to‐electricity and solar‐to‐fuel conversion owing to their tunable bandgaps and favorable optoelectronic properties. GaInP is widely used in monolithic tandem devices as a top absorber or charge‐carrier‐selective contact because of its suitable electronic structure. However, GaInP and related III–V materials are prone to photocorrosion under photoelectrochemical (PEC) operation and require protective layers that ensure chemical and electronic passivation. Atomic layer deposition (ALD), particularly plasma‐enhanced ALD (PE‐ALD), enables conformal deposition of films that enhance interfacial stability while maintaining efficient selective charge carrier transport. Here, the band alignment at the GaInP(100)/ interface is examined to determine whether the initial GaInP surface condition–either an atomically well‐defined, phosphorus‐rich surface or a naturally oxidized surface–affects interface formation during mild, low‐power remote oxygen PE‐ALD. Angle‐dependent X‐ray and ultraviolet photoelectron spectroscopy were used to probe the chemical and electronic structure of the buried interfaces. The results show that interface composition and band alignment are largely insensitive to the initial surface condition, with only minor differences in attenuation and interfacial energetics. These findings demonstrate the robustness of mild PE‐ALD for reproducible interface formation and support the design of protected III–V photoelectrodes for PEC applications.
ABSTRACT Replacing toxic Pb‐based absorbers with eco‐friendly alternatives remains a critical requirement for the sustainable commercialization of perovskite solar cells (PSCs). Here, a fully Cd‐free, lead‐free heterojunction PSC with the architecture Al/FTO/In 2 Se 3 /RbSn 0.5 Ge 0.5 I 3 /CuI/Ni is systematically designed and optimized using SCAPS‐1D. Seven electron transport layers (In 3 Se 4 , CdS, WS 2 , IGZO, SnS 2 , ZnSe, In 2 Se 3 ) and five hole transport layers (GO, GQD, PEDOT:PSS, CuSCN, CuI) are screened, identifying In 2 Se 3 and CuI as the optimal pair owing to their favorable spike‐type conduction‐band offset (+0.20 eV) and zero‐eV valence‐band offset, which suppress non‐radiative interfacial recombination as confirmed by Nyquist impedance analysis. Comprehensive optimization of absorber thickness, carrier concentration, bulk and interface defect densities, operating temperature, back‐contact work function, parasitic resistances, capacitance–voltage and capacitance–frequency response, carrier generation/recombination dynamics, and electric‐field distribution is performed. Under optimized conditions, the device delivers a power conversion efficiency of 26.01%, with Voc = 0.85 V, Jsc = 38.43 mA cm − 2 , and FF = 79.70%, surpassing previously reported RbSn 0.5 Ge 0.5 I 3 ‐based architectures. These findings establish clear design guidelines for high‐efficiency, environmentally benign Sn–Ge perovskite photovoltaics.
ABSTRACT Micro‐electrode arrays based on poly‐lactic acid substrates featuring gold electrodes coated with poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonate) are fabricated via maskless wet‐techniques and subtractive laser patterning. Devices exhibit stable electrical performance at the bench‐side over weeks and enable high‐quality neural interfacing in acute in vivo experiments. Two device layouts are presented: one for micro‐epicorticography and one for spinal cord stimulation. Cortical arrays are benchmarked against somatosensory evoked potentials in bilateral micro‐electrocorticography, showing robust contralateral activation and negative ipsilateral control. Spinal arrays activate sensory and motor pathways according to spatial features of the injected electric field, at fixed stimulation frequency and intensity, thus demonstrating localized stimulation. Long‐term (4‐months) implantation of spinal arrays results in almost complete substrate degradation and good device biocompatibility. These results demonstrate a versatile and sustainable fabrication workflow for prototyping of biodegradable substrate‐based neural interfaces, which opens new opportunities for transient neuroelectronics tailored to the application and the patient.
ABSTRACT Upon exposure to biological fluids, nanoparticles are rapidly coated by a layer of adsorbed proteins known as the protein corona (PC). PC composition strongly influences the nano‐bio interactions, yet its formation under physiologically relevant flow remains insufficiently explored. Here, a venous circulation‐mimicking system is designed to replicate physiological shear forces and dynamic protein exchange encountered during intravenous administration. PC formation on commonly utilized soft nanocarriers, including liposomes, poly(lactic‐co‐glycolic acid) nanoparticles (PLGA NPs), and lipid‐polymer hybrid nanoparticles (LPNPs) is investigated under biomimetic flow. The results demonstrate that flow‐induced PC formation alters the physicochemical properties of nanocarriers in a nanocarrier type‐dependent manner. Proteomic PC profiling reveals a largely shared protein core among all nanocarriers, alongside distinct material‐specific protein signatures. Uptake studies in A549 cells show that PC formation markedly reduces nanocarrier uptake for all formulations, indicating that pre‐formed coronas persistently modulate nanoparticle‐cell interactions. These findings highlight the central role of PC formation in defining nanocarrier biological identity and demonstrate that biomimetic circulation modulates corona organization without overriding serum‐driven effects. This study highlights the importance of incorporating dynamic and physiologically relevant conditions into in vitro models to better understand and evaluate nanocarrier behavior, and guide the rational design of nanomedicine platforms.
ABSTRACT An effective room‐temperature hydrogen gas sensor based on a Pd/TiN/TiO2 nanotube heterostructure is demonstrated. A novel ion beam deposition method is used to form a TiN/TiO2 heterostructure on TiO2 nanotubes formed by electrochemical anodization. Comprehensive physical characterization is performed, and x‐ray photoelectron spectroscopy reveals the presence of an oxynitride component within the TiN conformal layer. Current‐voltage measurements, via deposited Pd electrodes, show rectifying behavior in the TiN/TiO2 heterostructures, confirming barrier formation at the interface, while the bare TiN film displays ohmic behaviour. Upon exposure to 1% H2, a substantial current enhancement is observed, whose magnitude depends on the TiN thickness. The enhanced sensing response is attributed to catalytic H2 dissociation at the Pd electrodes and the subsequent modulation of the barrier formed at the TiN/TiO2 interface. These findings confirm that the dominant sensing mechanism originates from barrier height modulation at the interface. AC impedance spectroscopy suggests that the oxynitride interlayer enhances electronic conductivity and reduces charge recombination by creating a strong static electric field within the space charge region. The TiN/TiO2 nanotube system offers a promising platform for sensitive and reliable room‐temperature hydrogen detection through advanced interfacial engineering in solid‐state gas sensors.
ABSTRACT Ultrawide‐bandgap AlN is promising for next‐generation power devices but is limited by unstable surface chemistry and defective oxides induced by high‐temperature rapid thermal annealing (RTA). Here, we demonstrate a fluorination‐based interface engineering strategy using AlFx/SiNx passivation for p‐Si/n‐AlN heterojunction diodes fabricated via semiconductor grafting. A low‐damage pseudo‐atomic layer etching process removes RTA‐induced oxides, followed by XeF2 treatment to form an ultrathin AlFx layer, which is stabilized by an ALD‐grown SiNx capping layer. The engineered interface significantly suppresses defect‐assisted leakage, reducing reverse current by several orders of magnitude while maintaining forward conduction. Temperature‐dependent measurements reveal suppression of Poole–Frenkel emission, with the remaining high‐field leakage likely associated with AlN epilayer quality. X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) confirm reduced AlOx formation and the formation of a stable SiOx/SiON/AlFx interfacial layer. These results establish AlFx as an effective passivation scheme for low‐leakage AlN‐based heterojunction devices.
ABSTRACT Conventional characterization of magnetically tunable wetting properties on magnetoactive elastomer (MAE) surfaces prompts for the re‐deposition of water droplets when the surface state is to be changed, e.g., via the magnetic field. Motivated by potential applications of these smart materials in digital microfluidics, we experimentally investigate the wetting of MAE surfaces in time‐varying magnetic fields. Not only is the dynamical contact angle considered, but also the externally applied magnetic field can vary with time (square‐wave, rising‐edge and falling‐edge step excitations). It is found that the wetting characteristics of water droplets permanently present on MAE surfaces are different from the conventional approach, i.e., an increase in the magnetic field does not normally lead to an increase in the contact angle (CA). Additionally, it is hypothesized that formation and magnetic‐field enhancement of the wetting ridge on the surface of a soft (effective shear modulus < 10 kPa) MAE play an important role in dynamic wetting. A simple, purely geometrical theory is capable of describing the initial growth of the CA of an inflating droplet with time for the rising‐edge step magnetic field. Observed physical effects are discussed in the view of modern concepts regarding the surface and bulk properties of MAEs.
ABSTRACT Modern optoelectronics demand highly efficient transparent heaters that concurrently suppress electromagnetic interference (EMI). To address this, we present a fully solution‐processed, vacuum‐free Ni–Cu(–O)/Ag nanowire platform stabilized by a silica‐hybrid overcoat. The conformal Ni–Cu(–O) shell bridges interwire junctions, transforming fragile point contacts into robust pathways. This architectural breakthrough dramatically enhances Joule heating efficiency and thermal stability. At ∼75% transmittance, the ultrathin (55.6 nm) films deliver an exceptional heating performance up to 438°C (458°C·cm2·V−1) without defect‐driven failure, alongside extreme mechanical durability (ΔR/R0 < 1% over ∼7000 bending cycles). Crucially, this high‐performance heating platform also provides highly tunable EMI shielding. By tuning the Ni/Cu ratio, we effectively modulate the relative contributions of reflection and absorption loss. While high reflection governs far‐field shielding (total effectiveness ≥ 32 dB), adequate non‐reflective absorption is essential to dissipate trapped electromagnetic energy and prevent secondary internal reflections in integrated devices. Supported by direct near‐field magnetic scanning, our tailored core–shell architecture introduces a vital dissipative channel that actively suppresses this local magnetic noise, ensuring supreme electrothermal heating while enabling optimal, on‐demand EMI protection.
ABSTRACT Intracellular mitochondria are fascinating organelles that began their evolutionary journey as symbiotic α‐proteobacteria, negotiating safety and residence in (eukaryotic) cells in exchange for managing the host's energy demands. The archaic bacterium that was engulfed by cells has left its mark on modern mitochondria, including the well‐studied mitochondrial membrane, matrix, and genetic makeup. Similarly, nanoparticles, abundant in the atmosphere and inherently reactive, have interacted with life forms throughout their existence. One such multidimensional, complex reciprocity is the mitochondria‐nanoparticle interaction, which is biomedically relevant. Charged nanoparticles may disrupt the electron transport chain in the mitochondrial membrane that produces ATP, thereby depleting cells of their energy supply. Additionally, a disrupted electron transport produces excess reactive oxygen species, leading to oxidative stress, known to cause neurodegenerative, cardiovascular, and neurological diseases. However, recent advancements in nanotechnology and synthesis have uncovered novel opportunities to exploit this mitochondria‐nanoparticle interface, including theranostic possibilities via mitochondrial targeting with functionalized nanoparticles, with or without an encapsulated payload of theranostic agents such as peptides and genetic materials. This account will strive to understand the intricacies of this interface and elucidate the theranostic possibilities it offers.
ABSTRACT Single‐walled carbon nanotubes (SWCNTs) are considered promising channel materials for post‐Moore nanoelectronics due to their excellent carrier transport properties. However, the intrinsic chirality polydispersity of synthetic SWCNTs leads to significant bandgap non‐uniformity, which fundamentally limits the off‐state performance and integration density of carbon nanotube thin‐film transistors (CNT‐TFTs). Here, we systematically investigate the influence of statistical bandgap distributions on the transport characteristics and leakage mechanisms of CNT‐TFTs using three representative semiconducting SWCNT systems: single‐chirality‐enriched wide‐bandgap (6,5) SWCNTs, mixed‐chirality high‐pressure carbon monoxide (HiPco) SWCNTs with an intermediate average bandgap, and mixed‐chirality arc‐discharge SWCNTs with a smaller average bandgap. We show that narrow‐bandgap SWCNT networks exhibit higher on‐state currents due to reduced Schottky barriers but suffer from pronounced band‐to‐band tunneling (BTBT) under high electric fields, resulting in degraded on/off ratios and subthreshold stability. In contrast, devices based on single‐chirality‐enriched (6,5) SWCNTs effectively suppress BTBT, maintaining ultra‐low off‐state currents (Ioff < 10−11 A) and high on/off ratios (>106) even at high drain bias. These findings provide a material‐selection guideline for carbon‐based integrated circuits: wide‐bandgap, single‐chirality‐enriched SWCNTs are advantageous for leakage‐sensitive low‐power logic applications, whereas mixed‐chirality SWCNT networks with smaller average bandgaps are more suitable for high‐drive‐current analog and radio‐frequency electronics.
ABSTRACT We present a comparative soft x‐ray absorption spectroscopy (XAS) study of the sulfur L2,3 and molybdenum M2,3 absorption edges in MoS2 prepared by different fabrication routes, including bulk crystallization, mechanical exfoliation, chemical vapor deposition (CVD), and ionized jet deposition (IJD). The S L2,3 edges reveal pronounced differences in pre‐edge and main‐edge fine structure that sensitively reflect the degree of structural order, dimensionality, and electronic hybridization between S 3p and Mo 4d states. Bulk, exfoliated, and CVD‐grown samples exhibit well‐resolved multiple features characteristic of layered and ordered two‐dimensional (2D) MoS2, whereas as‐deposited IJD‐grown films display broadened, weakly structured spectra consistent with an amorphous phase and poorly defined stoichiometry. Upon moderate annealing at 250°C, IJD‐grown films develop clear spectral signatures of layered MoS2, indicating the formation of an ordered crystalline 2H‐MoS2 phase. Complementary analysis of the Mo M2,3 edges shows a concomitant narrowing and energy shift of the M3 feature toward values typical of well‐ordered 2D MoS2. These results demonstrate that S L2,3 and Mo M2,3 XAS provide a sensitive probe of synthesis‐dependent electronic structure in MoS2 and confirm IJD as a viable, low‐temperature route to electronically ordered 2D MoS2 phases.
ABSTRACT Flexible bioelectronic interfaces are transforming biomedical engineering by integrating electronic systems with soft biological tissues for in situ cell sensing and targeted therapy. Wide‐bandgap semiconductors have emerged as promising materials due to their inherent biocompatibility, mechanical robustness, and stable semiconducting properties. We recently grew thin single‐crystalline silicon carbide, a promising wide‐bandgap material for bioelectronics, on silicon substrates. Nano‐thin silicon carbide brings exciting new prospects to precise in‐body therapeutics. However, the degradation of materials working in relatively corrosive environments of biofluids, especially with the application of electrical currents, presents a major challenge. In this study, we demonstrate the design, wafer‐scale microfabrication process, and evaluation of a flexible cubic silicon carbide (3C‐SiC) electrode system for cellular bioelectrical sensing and irreversible electroporation ablation of cancer cells. The electrode system exhibits excellent electrochemical stability and mechanical compliance in physiological environments, ensuring conformal contact with soft tissue. Electroporation procedures on MDA‐MB‐231 breast cancer cells demonstrated highly efficient cell lysis after a short application of monophasic current. Concurrently, the electrodes supported robust real‐time recording of cellular activity, confirming their capability for sensing‐and‐actuation integration. Our results indicate a promising potential of wide‐bandgap semiconductors for robust and multifunctional bioelectronic interfaces toward targeted theragnostic at cellular levels.
ABSTRACT Biological systems often adapt to mechanical demands through localized tuning of material properties rather than morphological redesign. Here, we identify a natural strategy for functional optimization in gastropod radular teeth—microscale scraping tools subjected to substrate‐dependent loading. Using scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and nanoindentation, we quantify structure–composition–property relationships across closely related taxa occupying soft to hard feeding substrates. Tooth morphology remains largely conserved across taxa. In contrast, material composition and mechanical performance vary systematically with ecological demand. Soft‐substrate feeders exhibit predominantly organic teeth with low stiffness and hardness (Young's modulus ≈3–4 GPa; hardness ≈0.30–0.40 GPa). Mixed feeders show moderate calcium enrichment and intermediate properties. Rock‐scraping specialists display pronounced calcium and silicon incorporation, reaching stiffness and hardness values up to ≈10.8 and ≈1.1 GPa, respectively. Across all taxa, mechanical properties peak in the central radular region and decrease toward the margins, forming functional gradients that are most pronounced under high abrasion. These results demonstrate that localized mineral reinforcement of an organic matrix enables substrate‐specific mechanical optimization while maintaining conserved morphology. The radula thus represents a natural model of a functionally graded composite, illustrating how compositional modulation can precede structural change and providing design inspiration for abrasion‐resistant synthetic materials.
ABSTRACT Multi‐absorber III–V semiconductors represent the state of the art in high‐efficiency solar‐to‐electricity and solar‐to‐fuel conversion owing to their tunable bandgaps and favorable optoelectronic properties. GaInP is widely used in monolithic tandem devices as a top absorber or charge‐carrier‐selective contact because of its suitable electronic structure. However, GaInP and related III–V materials are prone to photocorrosion under photoelectrochemical (PEC) operation and require protective layers that ensure chemical and electronic passivation. Atomic layer deposition (ALD), particularly plasma‐enhanced ALD (PE‐ALD), enables conformal deposition of TiO2 films that enhance interfacial stability while maintaining efficient selective charge carrier transport. Here, the band alignment at the GaInP(100)/TiO2 interface is examined to determine whether the initial GaInP surface condition–either an atomically well‐defined, phosphorus‐rich surface or a naturally oxidized surface–affects interface formation during mild, low‐power remote oxygen PE‐ALD. Angle‐dependent X‐ray and ultraviolet photoelectron spectroscopy were used to probe the chemical and electronic structure of the buried interfaces. The results show that interface composition and band alignment are largely insensitive to the initial surface condition, with only minor differences in attenuation and interfacial energetics. These findings demonstrate the robustness of mild PE‐ALD for reproducible interface formation and support the design of protected III–V photoelectrodes for PEC applications.
ABSTRACT Robust polymer nanofilms are increasingly important for applications that require mechanically strong yet compliant membranes with nanoscale thickness and intimate interfacial contact. While biological membranes naturally combine flexibility, adaptability, and adhesion, achieving these features in synthetic nanomembranes remains challenging. Here, we report a one‐step strategy for the synthesis of centimeter‐scale, freestanding nanofilms via redox‐confined interfacial polymerization at a liquid‐liquid interface. Oxidative coupling of a multifunctional thiol monomer is spatially restricted to the aqueous‐organic interface, yielding continuous membranes with precisely tunable thicknesses ranging from tens to hundreds of nanometers. Structural and surface analyses reveal uniform network formation across all film thicknesses, consistent with a diffusion‐controlled growth mechanism. The resulting nanofilms exhibit high Young's modulus (425 MPa) and tensile strength (38 MPa), solid‐like viscoelastic behavior, and intrinsic adhesion to artificial skin despite the absence of dedicated bioadhesive functionalization. Together, these results establish redox‐confined interfacial polymerization as a versatile fabrication route to mechanically robust, freestanding nanomembranes with potential relevance for wearable sensing platforms, therapeutic interfaces, separation membranes, and other applications requiring strong ultrathin films with intrinsic adhesion.
