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Metal‐semiconductor interfaces are crucial components of optoelectronic and electrical devices, the performance of which hinges on intricate dynamics involving charge transport and mechanical interaction at the interface. Nevertheless, structural changes upon photoexcitation and subsequent carrier transportation at the interface, which crucially impact hot carrier stability and lifetime, remain elusive. To address this long‐standing problem, they investigated the electron dynamics and resulting structural changes at the Au/TiO2 interface using ultrafast electron diffraction (UED). The analysis of the UED data reveals that interlayer electron transfer from metal to semiconductor generates a strong coupling between the two layers, offering a new way for ultrafast heat transfer through the interface and leading to a coherent structural vibration that plays a critical role in propagating mechanical stress. These findings provide insights into the relationship between electron transfer and interfacial mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

[Display omitted] Nickel-based catalysts are suitable for water splitting to generate hydrogen. However, the low conductivity and weak stability have always been urgent issues to be addressed in nickel-based catalysts. Fe-doped nickel oxide/nickel phosphide (Fe-NiO/Ni 2 P) was prepared as a bifunctional electrocatalyst by doping metal and constructing heterogeneous interface. The introduction of Fe contributed to the reinforced interfacial coupling effect of NiO/Ni 2 P to promote charge transfer and accelerate reaction kinetics. The heterojunction regulated the interfacial charge density between NiO and Ni 2 P to improve the electronic environment of Ni2+ and enhance conductivity. The O-Fe-P bond at the heterogeneous interface induced the directional transfer of electrons and ensured the structure stability. The synergistic effect of Fe doping and heterogeneous interface increased the adsorption energy of *O and coordinated the adsorption energy of *H, advancing the catalytic performance. Fe-NiO/Ni 2 P exhibited the overpotential of 242 mV and 141 mV at 10 mA cm−2 for oxygen and hydrogen evolution, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] Rechargeable non-aqueous lithium-oxygen batteries (LOBs) have garnered increasing attention owing to their high theoretical energy density. However, their slow cathodic kinetics hinder efficient battery reactions. Nanoscale catalysts can effectively enhance electrocatalytic activity and atomic utilization efficiency. However, the agglomeration of nanoscale catalysts (such as cluster and single atoms) during continuous discharge/charge cycles leads to decreased electrochemical performance and poor cyclic stability. Herein, the ruthenium (Ru) atomic sites anchored on an O-doped molybdenum disulfide (O-MoS 2) catalyst (designated as Ru/O-MoS 2) was fabricated using a facile impregnation and calcination method. Strong Ru-O coupling between Ru atoms and the O-MoS 2 substrate optimizes the localized electronic structure, resulting in improved electrochemical performance and enhanced resistance to Ostwald ripening. When employed as a cathode catalyst for LOBs, Ru/O-MoS 2 catalyst exhibits a high reversible specific capacity (18700.5 (±59.8) mAh g−1), good rate capability, and enhanced long-term stability (115 cycles, 1200 h). This study encourages facile and efficient strategies for the development of effective and stable electrocatalysts for use in LOBs. [ABSTRACT FROM AUTHOR]

In order to enhance the hardness and wear resistance of 316L alloy, a strengthening phase was incorporated and laser-directed energy deposition was utilized to create a composite deposition layer consisting of coarse WC/316L, fine WC/316L, and coarse/fine WC/316L. Microstructural observations, phase composition analysis, Vickers hardness testing, interfacial coupling analysis, x-ray diffraction (XRD), and evaluation of friction-wear performance were systematically performed on the deposited samples. These investigations were undertaken to elucidate the impact of incorporating WC particles on both microstructural features and wear characteristics. Results showed that the average grain size of the composite deposition sample with coarse WC/316L decreased by 24% compared to 316L, with a 15.9% increase in hardness and a 97.6% decrease in wear rate. Similarly, the fine WC/316L composite deposition sample saw a 23% reduction in grain size, a 6.4% hardness increase, and a 62.4% decrease in wear rate compared to 316L. The hardness increased by 6.4%. The wear rate decreased by 62.4%. The coarse/fine WC/316L composite deposition samples exhibited a 34% decrease in average grain size, a 35.9% hardness increase, and a 99.1% decrease in wear rate compared to 316L. The addition of WC significantly enhanced the properties of 316L alloy, with coarse/fine WC showing the most significant improvements in microhardness and wear resistance. [ABSTRACT FROM AUTHOR]

Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions, and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hinge to achieve excellent solar conversion efficiency. In this work, tubular Ni1-xCoxS2-CdS heterostructures with reinforced Z-scheme charge transmission were constructed through an In-metal-organic framework (MOF) templated strategy. The Z-scheme charge transfer mechanism was sufficiently confirmed by combining density functional theory (DFT) calculation, X-ray photoelectron spectroscopy (XPS), surface photovoltage spectroscopy (SPV), and radical testing results. Crucially, the use of sodium citrate complexant contributes to the formation of intimate heterointerface, and the Fermi level gap between CdS and NiS2 is enlarged through Co doping into NiS2, which enhances the built-in electric field and photo-carriers transmission driving force for Ni1-xCoxS2-CdS heterojunction, resulting in an evidently promoted activity toward H2 evolution reaction (HER). Under visible-light (λ > 400 nm) irradiation, the Ni1-xCoxS2-CdS composite with 10 mol% Co doping and 80 wt.% CdS (NC0.10S-80% CdS) achieved an outstanding HER rate up to 35.94 mmol·g-1·h-1 (corresponding to the apparent quantum efficiency of 34.7% at 420 nm), approximately 76.4 times that of 3 wt.% Pt-loaded CdS and it is much superior to that of most CdS-based photocatalysts ever reported. Moreover, the good photocatalytic durability of Ni1-xCoxS2-CdS heterostructures was validated by cycling and long-term HER tests. This work could inspire the development of high-performance Z-scheme heterojunction via optimizing the morphology and interfacial charge transmission. [ABSTRACT FROM AUTHOR]

In research out of the sustainable electrochemical energy storage material, NiCo-LDH/MnO 2 composite has been prepared via simple hydrothermal method. The experimental characterizations of XRD, SEM/TEM and XPS have been utilized to explore the structure and morphology of prepared composite. The needle-like MnO 2 was found adhered to NiCo-LDH sheet. The composite's electrochemical properties were evaluated through cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. It has been realized that the MnO 2 dosage not only changes the composite's microstructure but also affects its electrochemical properties. The best specific capacitance (2602 F g−1 at a current density of 1 A g−1) was achieved for the composite sample with 38% MnO 2 (mass), which is almost two times high from the same composite in previous reports. With the sample, the assembled asymmetric supercapacitor exhibits a remarkable energy density of 19.56 Wh.Kg−1 at 800.29 W Kg−1. It could be attributed to the synergetic effects of two components as well as their good interfacial coupling. The good electrochemical activity makes our synthesized composite feasible to be applied as electrode material and provides valuable insights for the development of smart capacitors utilizing NiCo-LDH. [ABSTRACT FROM AUTHOR]

Abstract Metal‐semiconductor interfaces are crucial components of optoelectronic and electrical devices, the performance of which hinges on intricate dynamics involving charge transport and mechanical interaction at the interface. Nevertheless, structural changes upon photoexcitation and subsequent carrier transportation at the interface, which crucially impact hot carrier stability and lifetime, remain elusive. To address this long‐standing problem, they investigated the electron dynamics and resulting structural changes at the Au/TiO2 interface using ultrafast electron diffraction (UED). The analysis of the UED data reveals that interlayer electron transfer from metal to semiconductor generates a strong coupling between the two layers, offering a new way for ultrafast heat transfer through the interface and leading to a coherent structural vibration that plays a critical role in propagating mechanical stress. These findings provide insights into the relationship between electron transfer and interfacial mechanical and thermal properties.

To maximize the active sites and accelerate the electron transfer are of significant importance for developing efficient MoS 2 -based catalysts towards hydrogen evolution reaction (HER). Herein, we report a facile one-step construction of three-dimensional assembly in which Co doped MoS 2 nanoflowers are attached on partially sulfided nickel foam (Co–MoS 2 /Ni 3 S 2 /Ni). The three-dimensional structure enables maximum exposure of the active sites. Besides, interfacial interaction between MoS 2 and Ni 3 S 2 accelerates the electron transfer kinetics and increases the electrochemically active surface area. Additionally, electronic synergy effect of Co to MoS 2 promotes the formation of 1T-MoS 2 phase. Consequently, the optimized Co–MoS 2 /Ni 3 S 2 /Ni catalyst shows a superior HER performance with low overpotentials of 43 mV and 201 mV to achieve the current densities of 10 mA/cm2 and 100 mA/cm2, as well as an excellent stability of 11 h. Besides, Co–MoS 2 /Ni 3 S 2 /Ni has a small Tafel slope of 53 mV dec−1 which indicates a combined Volmer-Heyrovsky mechanism during the HER process. This work provides a novel insight for designing excellent MoS 2 -based HER catalysts through electronic modulation and interfacial engineering. [Display omitted] • One-step construction of three-dimensional Co–MoS 2 /Ni 3 S 2 /Ni assembly was realized. • Interfacial effect and electronic modulation are conducive to improving the HER activity of MoS 2. • Low overpotential of 43 mV to reach current density at 10 mA cm−2 was achieved. • The Co–MoS 2 /Ni 3 S 2 /Ni shows excellent stability in alkaline media. [ABSTRACT FROM AUTHOR]

In the vast family of two-dimensional (2D) van der Waals materials, 2D magnets have unique advantages in the experimental realization of numerous theoretical works and fundamental exploration of high-performance spintronic devices in the 2D limit. Fe3GeTe2 (FGT), as a typical 2D metallic ferromagnet, is a promising candidate to achieve functional devices at room temperature due to its relatively high Curie temperature (TC) and strong perpendicular magnetic anisotropy (PMA). Here, we investigated self-modulated magnetic properties of FGT nanoflakes in an ambient environment by anomalous Hall effect (AHE). Unique double square-shaped hysteresis loops are observed in oxidized Fe3GeTe2 nanoflakes induced by ambient effects. We propose a phenomenological model based on antiferromagnetic/ferromagnetic coupling in the FGT nanoflakes with oxidized surface layers to elucidate this observation. Compared with a single square-shaped hysteresis loop of well-preserved FGT, double square-shaped hysteresis loops exhibit four-resistance plateaus, which can be regarded as a kind of media for information storage or sensing, showing potential applications in next-generation spintronic devices. [ABSTRACT FROM AUTHOR]

Van der Waals materials and their interfaces play critical roles in defining electrical contacts for nanoelectronics and developing vehicles for mechanoelectrical energy conversion. In this work, we propose a vertical strain engineering approach by enforcing pressure across the heterostructures. First-principles calculations show that the in-plane band structures of 2D materials such as graphene, h-BN, and MoS2 as well as the electronic coupling at their contacts can be significantly modified. For the graphene/h-BN contact, a band gap in graphene is opened, while at the graphene/MoS2 interface, the band gap of MoS2 and the Schottky barrier height at contact diminish. Changes and transitions in the nature of contacts are attributed to localized orbital coupling and analyzed through the redistribution of charge densities, the crystal orbital Hamilton population, and electron localization, which yield consistent measures. These findings offer key insights into the understanding of interfacial interaction between 2D materials as well as the efficiency of electronic transport and energy conversion processes. [ABSTRACT FROM AUTHOR]

The rapid development of digital technology results in a tremendous increase in computational tasks that impose stringent performance requirements on next‐generation computing. Biological neurons with fault tolerance and logic functions exhibit powerful computing capacity when facing complex real‐world problems, which strikes the inspiration for the development of highly energy‐efficient brain‐like computing. Herein, a novel device architecture, an electrolyte‐manipulated ferroelectric organic neuristor, which emulates biological neurons to perform both neuromorphic and reconfigurable logic‐in‐memory operations in a single cell, is proposed. The interfacial coupling of ions and dipoles in the neuristor contributes to the tunable synaptic behaviors of short‐ to long‐term plasticity. Notably, by virtue of lateral capacitive coupling, the neuristor is effectively controlled by multiple in‐plane gates to achieve heterosynaptic plasticity. An artificial neural network exhibits robust recognition ability with high accuracy of 93.7% in speech recognition, further demonstrating the feasibility of the neuristor for neuromorphic computing. Additionally, reconfigurable logic‐in‐memory operations (OR and AND) are successfully demonstrated in a single device. Therefore, the devices shed new light on the development of more brain‐inspired computing systems in the era of big data. [ABSTRACT FROM AUTHOR]

The rapid development of digital technology results in a tremendous increase in computational tasks that impose stringent performance requirements on next‐generation computing. Biological neurons with fault tolerance and logic functions exhibit powerful computing capacity when facing complex real‐world problems, which strikes the inspiration for the development of highly energy‐efficient brain‐like computing. Herein, a novel device architecture, an electrolyte‐manipulated ferroelectric organic neuristor, which emulates biological neurons to perform both neuromorphic and reconfigurable logic‐in‐memory operations in a single cell, is proposed. The interfacial coupling of ions and dipoles in the neuristor contributes to the tunable synaptic behaviors of short‐ to long‐term plasticity. Notably, by virtue of lateral capacitive coupling, the neuristor is effectively controlled by multiple in‐plane gates to achieve heterosynaptic plasticity. An artificial neural network exhibits robust recognition ability with high accuracy of 93.7% in speech recognition, further demonstrating the feasibility of the neuristor for neuromorphic computing. Additionally, reconfigurable logic‐in‐memory operations (OR and AND) are successfully demonstrated in a single device. Therefore, the devices shed new light on the development of more brain‐inspired computing systems in the era of big data.

Tin selenide (SnSe2) is considered a promising anode of the lithium‐ion battery because of its tunable interlayer space, abundant active sites, and high theoretical capacity. However, the low electronic conductivity and large volume variation during the charging/discharging processes inevitably result in inadequate specific capacity and inferior cyclic stability. Herein, a high‐throughput wet chemical method to synthesize SnSe2/SnSe heterostructures is designed and used as anodes of lithium‐ion batteries. The hierarchical nanoflower morphology of such heterostructures buffers the volume expansion, while the built‐in electric field and metallic feature increase the charge transport capability. As expected, the superb specific capacity (≈911.4 mAh g−1 at 0.1 A g−1), high‐rate performance, and outstanding cyclic stability are obtained in the lithium‐ion batteries composed of SnSe2/SnSe anodes. More intriguingly, a reversible specific capacity (≈374.7 mAh g−1 at 2.5 A g−1) is maintained after 1000 cycles. The internal lithium storage mechanism is clarified by density functional theory (DFT) calculations and in situ characterizations. This work hereby provides a new paradigm for enhancing lithium‐ion battery performances by constructing heterostructures. [ABSTRACT FROM AUTHOR]

• The symmetry of MoS 2 could be broken showing typical optical anisotropic property. • The MoS 2 /BiOCl exhibits polarization-sensitive photodetection with dichroic ratio of 1.10. • The type II band alignment can significantly reduce the dark noise current and enhance the value of specific detectivity. While MoS 2 as a two-dimensional semiconductor exhibits light-intensity broadband photodetection and can be synthesized using a 12-inch wafer-scale growth technique, its isotropic optical properties limit its application in multi-dimensional photodetection including polarization, intensity and wavelength photodetection. In this study, BiOCl flakes with optical anisotropy are employed to fabricate MoS 2 /BiOCl van der Waals (vdW) heterojunction. Characterizing with Raman spectroscopy, second harmonic generation (SHG), and kelvin probe force microscope (KPFM), strong interfacial coupling between MoS 2 and BiOCl is observed, which is potent enough to break the symmetry of MoS 2 , resulting in distinctive anisotropic optical properties. The electrical and photoelectrical properties of MoS 2 /BiOCl vdW heterojunction-based phototransistors are studied. The highest responsivity and specific detectivity under 460 nm illumination reaches 188 A/W and 5 × 1013 Jones, respectively. Moreover, the photocurrent of MoS 2 /BiOCl phototransistor exhibits typical polarization-sensitive behavior at 633 nm with a polarization dichroic ratio of 1.10, which is caused by the uniaxial strain from the interfacial coupling. This study paves the way for the development of a room-temperature multi-dimensional photodetector based on symmetry-broken MoS 2. [ABSTRACT FROM AUTHOR]

• High pressure drives the rapid implantation of polyaniline in host [VO n ] lattices. • Bipolar protonation provides abundant active sites for ion/electron mobility. • Interfacial coupling bonds effectively relieve the intercalation stress of V 2 O 5. • Charge storage process with multiple ions was elucidated by in situ FTIR/Raman. • AZIBs exhibits ultrahigh-rate and ultralong-life zinc ions storage performance. Durable cathode materials with high specific capacity are essential for aqueous zinc ion batteries (AZIBs). However, vanadium-based materials endure irreversible structural collapse, sluggish diffusion kinetics, and low working voltage. In this study, we propose a unique pressure-driven molecule implantation (PMI) strategy to fabricate a laminar organic–inorganic hybrid cathode (PMI-VO) for AZIBs by coupling polyaniline (PANI) with vanadium oxide. The bipolar protonation of implanted electroactive PANI provides abundant active sites for ion/electron transfer and Zn2+/H+ storage in PMI-VO. Importantly, the formed C-V-O interfacial coupling bonds in the cycling process effectively relieve the intercalation stress and strengthen the redox kinetics and structural integrity of V 2 O 5. In situ infrared spectroscopy and theoretical calculations reveal the PMI-induced multiple ions storage mechanisms in the PMI-VO cathode. Accordingly, PMI-VO cathode performs a superior specific capacity of 522 mAh∙g−1 at 0.2 A∙g−1, a high operating voltage of 0.86 V, a high energy density (387.4 Wh∙kg−1), and splendid long-life stability (over 15,000 cycles at 20 A∙g−1 with 191 mAh∙g−1). Therefore, this pressure-driven molecule implantation strategy provides a pioneering method to fabricate superior cathode materials of advanced AZIBs. [ABSTRACT FROM AUTHOR]

The construction of heterostructures is a versatile tactic to enhance catalytic activity. However, it is still elusive to realize the modulation of the interlayer spacing in this way to further improve the performance. Here, strong interfacial coupling between CoSe2 and MoSe2 by constructing CoSe2/MoSe2 heterostructures is achieved. The interlayer spacing of MoSe2 is compressed by 0.3 Å. The enhanced charge transfer is validated by X‐ray absorption spectroscopy and X‐ray photoelectron spectroscopy. Coupled with the morphology of hollow microtubes, which can facilitate the exposure of active sites, CoSe2/MoSe2 heterostructures reported here exhibit high activity (119 mV at 10 mA cm−2) and excellent stability with small degradation after 50 h operation, surpassing other analogous powdered electrocatalysts. This work sheds light on the importance of tuning the interlayer spacing to improve electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Probing and manipulating the intriguing nonlinear optical responses in van der Waals (vdW) ferroelectrics offer opportunities for their applications in nanophotonics. Here, we report the observation of giant and tunable second-harmonic generation (SHG) in ferroelectric CuInP 2 S 6 (CIPS) and CIPS/MoS 2 heterostructures. The results show that CIPS, ranging from multilayer to bulk-like samples, all exhibit strong SHG with giant anisotropy. The SHG anisotropy is attributed to the local strain along the a -axis that naturally exists in CIPS, as evidenced by piezoresponse force microscopy measurement. We further realized the strong modulation of SHG in CIPS by interfacing with monolayer MoS 2 . A combination of polarization, temperature, and thickness-dependent SHG and photoluminescence analyses shows that the nonlinear optical signal control in CIPS/MoS 2 heterostructures is unrelated to the polar symmetry of CIPS and MoS 2 but is driven by light absorption-mediated interfacial coupling. Our study provides a material platform based on vdW ferroelectric heterostructures for achieving dynamic control of nonlinear optical responses, which shows great potential applications in modern nanophotonics.

Metal-semiconductor interfaces are crucial components of optoelectronic and electrical devices, the performance of which hinges on intricate dynamics involving charge transport and mechanical interaction at the interface. Nevertheless, structural changes upon photoexcitation and subsequent carrier transportation at the interface, which crucially impact hot carrier stability and lifetime, remain elusive. To address this long-standing problem, they investigated the electron dynamics and resulting structural changes at the Au/TiO 2 interface using ultrafast electron diffraction (UED). The analysis of the UED data reveals that interlayer electron transfer from metal to semiconductor generates a strong coupling between the two layers, offering a new way for ultrafast heat transfer through the interface and leading to a coherent structural vibration that plays a critical role in propagating mechanical stress. These findings provide insights into the relationship between electron transfer and interfacial mechanical and thermal properties., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

We designed an edge-sites 2D/0D/2D based TiO2@Au/g-C3N4 Z-scheme photocatalytic system consists of highly exposed (001) TNSs@Au edge-site heterojunction, and the Au/g-C3N4 interfacial heterojunction. The designed photocatalyst was prepared by a facile and controlled hydrothermal synthesis strategy via in-situ nanoclusters-to-nanoparticles deposition technique and programable calcination in N2 atmosphere to get edge-site well-crystalline interface, followed by chemically bonded thin overlay of g-C3N4. Photocatalytic performance of the prepared TNSs@Au/g-C3N4 catalyst was evaluated by the photocatalytic degradation of organic pollutants in water under visible light irradiation. The results obtained from structural and chemical characterization conclude that the inter-facet junction between highly exposed (001) and (101) TNSs surface, and TNSs@Au interfacial heterojunction formed by a direct contact between highly crystalline TNSs and Au, are the key factors to enhance the separation efficiency of photogenerated electrons/holes. On coupling with overlay of g-C3N4 2D NSs synergistically offer tremendous reactive sites for the potential photocatalytic dye degradation in the Z-scheme photocatalyst. Particularly in the designed photocatalyst, Au nanoparticles accumulates and transfer the photo-stimulated electrons originated from anatase TNSs to g-C3N4via semiconductor-metal heterojunction. Because of the large exposed reactive 2D surface, overlay g-C3N4 sheets not only trap photoelectrons, but also provide a potential platform for increased adsorption capacities for organic contaminants. This work establishes a foundation for the development of high-performance Z-scheme photocatalytic systems.

We have demonstrated the improved performance of oxygen evolution reactions (OER) using Au/nickel phosphide (Ni12P5) core/shell nanoparticles (NPs) under basic conditions. NPs with a Ni12P5 shell and a Au core, both of which have well-defined crystal structures, have been prepared using solution-based synthetic routes. Compared with pure Ni12P5 NPs and Au-Ni12P5 oligomer-like NPs, the core/shell crystalline structure with Au shows an improved OER activity. It affords a current density of 10 mA/cm2 at a small overpotential of 0.34 V, in 1 M KOH aqueous solution at room temperature. This enhanced OER activity may relate to the strong structural and effective electronic coupling between the single-crystal core and the shell. [Figure not available: see fulltext.].

Herein, we presented a simple two-step hydrothermal method to fabricate noble-metal-free 3D net-like Ni 3 (VO 4) 2 ultrathin nanosheets coupled with the MoS 2 @CFC interface. Benefiting from the reciprocally binding structure and interfacial coupling effects between Ni 3 (VO 4) 2 nanosheet and MoS 2 @CFC, the catalytically active area was expanded, and the intrinsic activity toward HER was significantly improved. [Display omitted] • Ni 3 (VO 4) 2 with 3D net-like structure was constructed on the MoS 2 nanosheets. • The interface coupling structure was formed between MoS 2 and Ni 3 (VO 4) 2. • This work provides new perspectives to construct efficient electrocatalysts. The use of cheap and efficient electrocatalyst for the production of hydrogen is the key to solving the current energy crisis. Herein, we used a two-step hydrothermal process to fabricate noble-metal-free 3D net-like Ni 3 (VO 4) 2 ultrathin nanosheets coupled with MoS 2 @CFC interface. Unlike the traditional two-dimensional composite materials, Ni 3 (VO 4) 2 ultrathin nanosheets intersect with MoS 2 nanosheets grown on CFC in a 3D net-like structure (Ni 3 (VO 4) 2 /MoS 2 @CFC). Due to the mutual combination of structures and the interfacial coupling cooperation effect between Ni 3 (VO 4) 2 nanosheet and MoS 2 @CFC, the catalytically active area was expanded, and the intrinsic activity toward HER was significantly improved. Ni 3 (VO 4) 2 /MoS 2 @CFC showed high activity at the industrial temperature (75 °C), with an overpotential of 77 mV (10 mA/cm2) and a 65 mV/dec Tafel slope. This material showed good stability at 0.5 M H 2 SO 4. This work provides a heterostructure scheme for the construction of a novel noble metal-free electrocatalyst to promote hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Blending Polyetheretherketone (PEEK) with Polyvinyl alcohol (PVA) is promising to obtain a composite scaffold combining the excellent biomechanical properties of PEEK and the remarkable degradability of PVA. However, the weak interfacial bonding between nonpolar PEEK and polar PVA would result in poor mechanical properties. In this study, owing to its unique amphiphilic properties, graphene oxide (GO) was employed to enhance the interfacial bonding between PEEK and PVA in PEEK/PVA scaffolds that were fabricated by laser 3D printing. On the one hand, the large π-conjugated structure of GO formed strong π-π interactions with the benzene rings in PEEK. On the other hand, the oxygen-containing groups of GO formed strong hydrogen bonds with the hydroxyl groups of PVA. As a result, the interfacial free energy between PEEK and PVA decreased from 37.4 to 29.6 mJ/m2 according to the harmonic-mean rule, and the PVA phase in PEEK matrix became much fine and uniform, indicating a reinforced interfacial bonding. Correspondingly, the strength and modulus of PEEK/PVA scaffolds increased by 97.16% and 147.06%, respectively, for a GO loading of 1%. Furthermore, the scaffolds exhibited good hydrophilicity and degradability, and promoted cell attachment and proliferation in vitro and osteogenic differentiation and bone regeneration in vivo.

Due to promising functionalities that may dramatically enhance spintronics performance, antiferromagnets are the subject of intensive research for developing the next-generation active elements to replace ferromagnets. In particular, the recent experimental demonstration of tunneling magnetoresistance and electrical switching using chiral antiferromagnets has sparked expectations for the practical integration of antiferromagnetic materials into device architectures. To further develop the technology to manipulate the magnetic anisotropies in all-antiferromagnetic devices, it is essential to realize exchange bias through the interface between antiferromagnetic multilayers. Here, the first observation on the omnidirectional exchange bias at an all-antiferromagnetic polycrystalline heterointerface is reported. This experiment demonstrates that the interfacial energy causing the exchange bias between the chiral-antiferromagnet Mn 3 Sn/collinear-antiferromagnet MnN layers is comparable to those found at the conventional ferromagnet/antiferromagnet interface at room temperature. In sharp contrast with previous reports using ferromagnets, the magnetic field control of the unidirectional anisotropy is found to be omnidirectional due to the absence of the shape anisotropy in the antiferromagnetic multilayer. The realization of the omnidirectional exchange bias at the interface between polycrystalline antiferromagnets on amorphous templates, highly compatible with existing Si-based devices, paves the way for developing ultra-low power and ultra-high speed memory devices based on antiferromagnets., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

[Display omitted] • Ultrathin MoS 2 @NiFe 2 O 4 is constructed by a facile hydrothermal and amine-hydrolysis. • MS@NiFeO delivers highly efficient OER performance and photodegradation activity. • Stability and reuse of MS@NiFeO are quite stable and remain little change. • The *OH and *O 2 − reactive species confirms the photocatalytic mechanism by ESR spectroscopy. Rational design and highly efficient dual-functional catalyst are still difficult to develop for electrocatalytic oxygen evolution reaction and degradation of RhB dye pollutant. Herein, we report a highly efficient "bandgap matching and interfacial coupling" strategy to synthesize nano-assembled ultrathin layered MoS 2 @NiFe 2 O 4 (MS@NiFeO) bifunctional catalyst constructed by the hydrothermal route and subsequently amine-hydrolysis. The OER performance of the prepared MS@NiFeO catalyst delivers a low overpotential of 290 mV at 10 mA/cm2 and Tafel slope is 69.2 mV dec−1 in an alkaline solution. In addition, the nano-assembled ultrathin layered structure of MS@NiFeO showed a highly efficient (96.37%) RhB dye degradation performance than that of MoS 2 nanosheets and NiFe 2 O 4 nanostructures. Unique nanostructure of ultrathin layered MS@NiFeO with suitable band matching, interfacial charge transfer, high surface area and more active sites favored for the enhancement of the catalytic activity. This work presents an unpretentious construction and low-cost production strategy to synthesize bifunctional hybrid catalyst for oxygen evolution reaction as well as degradation of organic pollutant with superior efficiency and longer stability. [ABSTRACT FROM AUTHOR]

• Antiferromagnetics-based coercivity control in hematite/permalloy heterostructures. • Magnetic and structural studies of epitaxial hematite thin films across the Morin transition. • Thickness dependence of the Interfacial coupling between hematite and permalloy across Morin transition. Interfacial effects between antiferromagnetic (AFM) and ferromagnetic (FM) materials have long been a center of magnetism studies. Aside from the exchange bias occurring at the AFM/FM interface, controlling the coercivity is another significant topic in magnetic recordings. The coercivity of FM materials is often determined through varying grain size, alloy composition, density of defects, etc., which is set during material growth and offers limited room for modification after growth. Hematite (α - F e 2 O 3) is an AFM material that undergoes a temperature-controlled spin-flip transition, the so-called Morin transition. This transition gives an extra degree of freedom making hematite an intriguing component to study the exchange coupling when interfaced with an FM material. In this work, changes in the magnetic properties of soft magnetic permalloy (N i 81 F e 19 , or Py) thin films grown on hematite were studied across the Morin transition. Surprisingly, these samples showed a remarkable change in coercivity during the Morin transition. We attribute this effect to the magnetic domain mixture of hematite during the Morin transition. Our findings present a novel method of controlling the coercivity of plain ferromagnetic thin films. [ABSTRACT FROM AUTHOR]

Sewage containing heavy metal ions (HMIs) has caused serious damage to ecological environment and human health when discharged without treatment. In this work, a practical filter has been made with cellulose/zinc oxide/magnesium hydroxide (CelZnMg) ternary composite prepared via a simple hydrothermal method. The characterizations show that granular ZnO and lamellar Mg(OH) 2 evenly distribute on cellulose. The electrostatic attraction drives the coupling of cellulose and ZnO/Mg(OH) 2 , and the formed CelZnMg is significantly stabilized by interfacial hydrogen bonds and dative bonds. On the other hand, the cellulose substrate also immobilizes the recovered HMIs and completely and easily separates them from wastewater. The ternary composite has outstanding bifunctional performance. Its Mg(OH) 2 component offers high HMIs-removing capability; for instance, q max of Cd2+ and Cu2+ in 400 mL 500 mg·L–1 solution reaches 693.2 and 764.6 mg·g–1 respectively. The ZnO moiety endows the antibacterial property, which inhibits the growth of Staphylococcus aureus and Escherichia coli. The inhibition effect indicates that cellulose in the composite is stable during application. Due to its multiple merits, the CelZnMg filter would be a perspective candidate for the use as water treatment agent. [Display omitted] • Biobased fibrous cellulose composite is prepared by a simple hydrothermal method. • Granular ZnO and lamellar Mg(OH) 2 evenly and chemically anchor on cellulose. • Chemical and structural stability is enhanced by incorporating ZnO. • Mg(OH) 2 plays the key role in HMIs, which also slightly raises antibacterial effect. • Cellulose immobilizes recovered HMIs and completely avoids the secondary pollution. [ABSTRACT FROM AUTHOR]

Benefiting from abundant sodium resources, sodium-ion batteries (SIBs) have attracted abundant interest in the past decade, which hold great practical prospects for future large-scale energy storage applications. However, sluggish reaction kinetics are the main obstacle to the development of high-performance SIBs. Herein, nitrogen-doped carbon-coated MoSe 2 (MoSe 2 @NC) nanosheets are developed by a facile hydrothermal with subsequent calcination strategy. The expanded crystalline planes of MoSe 2 facilitate the insertion/extraction kinetics of Na+. The coated nitrogen-doped carbon layers effectively enhance the electric conductivity and restrict the agglomeration of MoSe 2. The Mo–C bonding formed by interfacial coupling between the MoSe 2 and nitrogen-doped carbons facilitates the charge transfer in the MoSe 2 @NC. As a result, the MoSe 2 @NC anode exhibits a reversible discharge capacity of 427.6 mAh g−1 at 0.1 A g−1 with a high cyclic stability of 337.9 mAh g−1 after 200 cycles at 0.5 A g−1. The N-doped carbon layers effectively restrict the agglomeration of MoSe 2 , and the expanded crystalline planes with strong interfacial Mo–C bonding facilitate the insertion/extraction reaction kinetics. [Display omitted] • The expanded crystalline planes of MoSe 2 @NC facilitate the insertion/extraction reaction kinetics. • The coated N-doped carbon layers effectively enhance the electric conductivity and restrict the agglomeration of MoSe 2. • The interfacial coupling of Mo–C bonding between the MoSe 2 and N-doped carbons facilitates the charge transfer. [ABSTRACT FROM AUTHOR]

The generally nonpolar SrTiO 3 has attracted more attention recently because of its possibly induced novel polar states and related paraelectric-ferroelectric phase transitions. By using controlled pulsed laser deposition, high-quality, ultrathin, and strained SrTiO 3 layers were obtained. Here, transmission electron microscopy and theoretical simulations have unveiled highly polar states in SrTiO 3 films even down to one unit cell at room temperature, which were stabilized in the PbTiO 3 /SrTiO 3 /PbTiO 3 sandwich structures by in-plane tensile strain and interfacial coupling, as evidenced by large tetragonality (∼1.05), notable polar ion displacement (0.019 nm), and thus ultrahigh spontaneous polarization (up to ∼50 μC/cm 2 ). These values are nearly comparable to those of the strong ferroelectrics as the PbZr x Ti 1- x O 3 family. Our findings provide an effective and practical approach for integrating large strain states into oxide films and inducing polarization in nonpolar materials, which may broaden the functionality of nonpolar oxides and pave the way for the discovery of new electronic materials.

Blending Polyetheretherketone (PEEK) with Polyvinyl alcohol (PVA) is promising to obtain a composite scaffold combining the excellent biomechanical properties of PEEK and the remarkable degradability of PVA. However, the weak interfacial bonding between nonpolar PEEK and polar PVA would result in poor mechanical properties. In this study, owing to its unique amphiphilic properties, graphene oxide (GO) was employed to enhance the interfacial bonding between PEEK and PVA in PEEK/PVA scaffolds that were fabricated by laser 3D printing. On the one hand, the large π-conjugated structure of GO formed strong π-π interactions with the benzene rings in PEEK. On the other hand, the oxygen-containing groups of GO formed strong hydrogen bonds with the hydroxyl groups of PVA. As a result, the interfacial free energy between PEEK and PVA decreased from 37.4 to 29.6 mJ/m2 according to the harmonic-mean rule, and the PVA phase in PEEK matrix became much fine and uniform, indicating a reinforced interfacial bonding. Correspondingly, the strength and modulus of PEEK/PVA scaffolds increased by 97.16% and 147.06%, respectively, for a GO loading of 1%. Furthermore, the scaffolds exhibited good hydrophilicity and degradability, and promoted cell attachment and proliferation in vitro and osteogenic differentiation and bone regeneration in vivo. [ABSTRACT FROM AUTHOR]

Developing high activity, strong durability, and cost-efficient electrocatalysts for the hydrogen evolution reaction (HER) is critical for the sustainable production of hydrogen energy. Herein, we have rationally designed three-dimensional (3D) heterogeneous catalyst of hollow nickel phosphide spheres coupled with molybdenum sulfide nanosheets (Ni2P@MoS2). Benefiting from the hollow spherical structure and the coupling effects between MoS2 and Ni2P, Ni2P@MoS2 shows superior activity for hydrogen generation over a wide pH range. It displays overpotentials of 181, 269 and 535 mV in 1.0 M KOH, 0.5 M H2SO4 and 1.0 M PBS, respectively, at a current density of 10 mAcm-2. A series of characterization techniques demonstrate that the strong coupling interaction between Ni2P and MoS2 effectively optimizes the electronic structure of the Ni2PMoS2 3D/2D interfaces, beneficial for regulating H* adsorption energy. This work offers a novel strategy for enhancing the HER performance of metal phosphide/sulfide catalysts by constructing heterostructured materials with abundant 3D/2D interfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amorphous-crystalline interface coupling deign is proposed for active OER catalyst. • It is demonstrated by crystalline Fe 2 O 3 supported ultrathin amorphous NiFe(OH) x. • Reduced surface charge accumulation and promoted high valence Ni state is confirmed. • Enhanced OER activity is achieved in AEM electrolyzer at high current density. Amorphous NiFe-based oxyhydroxides can provide abundant active sites for oxygen evolution reaction (OER) in alkaline water splitting, but their disordered atomic arrangement leads to severe charge accumulation and electrochemical polarization at high current density. To address this issue, a crystalline Fe 2 O 3 supported ultrathin amorphous NiFe oxy-hydroxide amorphous-crystalline interface coupling design is proposed. In this design, the interfacial Fe3+ in Fe 2 O 3 as a strong Lewis acid is conducive for trapping the electrons in amorphous NiFe(OH) x , reducing the surface charge accumulation, electrochemical polarization, and improves its OER performance. Meanwhile, in-situ Raman, in-situ IR and XPS analysis reveal that, the electrons transfer is accompanied with Ni2+ oxidation into the highly OER active Ni3+ species. Benefited from this design, the OER overpotentials of the resulting NiFe(OH) x /Fe 2 O 3 NAs catalyst are measured to be 111 and 233 mV at 10 and 100 mA cm−2, respectively, superior than many reported OER electrocatalysts. The anion exchange membrane water electrolyzer using NiFe(OH) x /Fe 2 O 3 NAs delivers a current density of 600 mA cm−2 at a small cell voltage of 1.75 V, and exhibits excellent stability performance in high-current–density condition. This work provides a promising alternative strategy for the development of high-performance amorphous OER catalysts. [ABSTRACT FROM AUTHOR]

• Perpendicular magnetic anisotropy (PMA) in CoPt/CoO x bilayers has been enhanced. • The CoPt/CoO x bilayers show strong perpendicular exchange bias (PEB). • The thin CoO x layer has been formed with Co at different oxidization state. • Up to Q = 20%, the oxidization of Co in CoO x layer monotonously promotes the PMA. • The strongest PEB occurs at Q = 10% due to the phase transition of CoO x layer. The magnetic properties of the CoPt/CoO x bilayers have been investigated in this work. Compared with the CoPt single layer, enhanced perpendicular magnetic anisotropy (PMA) and strong perpendicular exchange bias (PEB) have been observed in the CoPt/CoO x bilayers. The thin CoO x layer with Co at different oxidization state, formed by controlling the oxygen gas flow rate ratio in the oxygen and argon gas mixture during the magnetron sputtering, has been found to significantly affect the magnetic anisotropy and exchange bias of the films. Up to 20% oxygen flow rate ratio, the oxidization of Co in CoO x layer monotonously promotes the PMA. While the maximum value of PEB is obtained at 10% oxygen flow rate ratio, and then decreases for further oxidation due to the phase transition from CoO to Co 3 O 4 with a smaller AFM anisotropy constant. Our study provides useful information for fabricating and understanding ferromagnet/antiferromagnet thin films with strong perpendicular magnetic anisotropy and perpendicular exchange bias. [ABSTRACT FROM AUTHOR]

Interface engineering in transition metal oxide heterostructures not only gives rise to exotic physical phenomena, but also has potential applications in spintronics. In this study, we demonstrate the appearance of strong interfacial coupling in 5 d paramagnetic SrIrO 3 and 3 d ferromagnetic La 0.67 Sr 0.33 MnO 3 bilayers, which manifests itself in the dramatic enhancement of coercivity by about 70 times larger than that of the single La 0.67 Sr 0.33 MnO 3 layer and the observation of an unexpected exchange bias effect up to 40 K. Systematic magnetic analysis further reveals the emergence of an interfacial spin glass state in this 5 d -3 d oxide bilayer. This interfacial-coupling-induced spin glass state is the underlying origin of the unconventional exchange bias effect rarely observed in paramagnetic/ferromagnetic heterostructures. • High-quality 5 d SrIrO 3 /3 d La 0.67 Sr 0.33 MnO 3 bilayers have been epitaxially grown. • An unexpected exchange bias effect is observed for the first time in the bilayer. • The exchange bias effect is driven by interfacial spin glass. [ABSTRACT FROM AUTHOR]

The disadvantages of layered double hydroxides (LDHs) such as easy stacking, poor inherent conductivity, and limited versatility hinder their application in splitting water and zinc-air batteries (ZABs). Interface engineering to regulate the electron distribution of LDHs by introducing another component is a way to compensate for the poor electron transport capacity of LDHs during catalysis. Herein, a hierarchical structure is synthesized by assembling CoFe-LDH nanosheets onto the surface of layered N-doped porous carbon (NPC), CoFe-LDH@NPC, by using an interface engineering strategy. CoFe-LDH@NPC has high catalytic activity for the oxygen/hydrogen evolution reaction (OER/HER) with overpotentials of 280/100 mV, respectively. The two-electrode water splitting catalyzed by CoFe-LDH@NPC only needs 1.61 V to drive a current density of 10 mA cm -2 for 60 h. The theoretical results show that there is an electron-deficient/electron-rich interface between the NPC substrate and the CoFe-LDH in CoFe-LDH@NPC. The electrons on the coupling interface are easily transferred, which results in a change of the adsorption behavior of the reaction intermediates and improves the catalytic activity for the OER and HER. In addition, CoFe-LDH@NPC-catalyzed rechargeable flexible ZABs have excellent performance with low charge-discharge polarization (0.87 V) and a long-term stability of 65 h.

We have prepared a composite of ferrimagnetic ferrite Co 1.75 Fe 1.25 O 4 and non-magnetic oxide BaTiO 3 . The ferrite composition Co 1.75 Fe 1.25 O 4 has been prepared by chemical co-precipitation and subsequently heated at different temperatures. The heat treated ferrite powder has been mixed with BaTiO 3 powder with mass ratio 1:1 and the mixed powder has been finally heated at 1000 °C to form composite material. Structural phase of the composite material has been confirmed by high quality Synchrotron X-ray diffraction pattern and Micro-Raman spectra. The grain surface morphology and elemental composition have been studied by Scanning electron microscope and Energy dispersive X-ray analysis. The distribution of magnetic exchange interactions and blocking behavior of the ferrimagnetic grains in composite samples has been understood by analyzing the temperature and magnetic field dependence of dc magnetization. Finally, information on modified micro-structure and ferrimagnetic parameters in composite samples has been obtained as the variation of annealing temperature of the ferrite component before making composite. [ABSTRACT FROM AUTHOR]

Here, crystal structure, electronic structure, chemical substitution, pressure-dependent superconductivity, and thickness-dependent properties in FeSe-based superconductors are systemically reviewed. First, the superconductivity versus chemical substitution is reviewed, where the doping at Fe or Se sites induces different effects on the superconducting critical temperature (Tc). Meanwhile, the application of high pressure is extremely effective in enhancing Tc and simultaneously induces magnetism. Second, the intercalated-FeSe superconductors exhibit higher Tc from 30 to 46 K. Such an enhancement is mainly caused by the charge transfer from the intercalated organic and inorganic layer. Finally, the highest Tc emerging in single-unit-cell FeSe on the SrTiO3 substrate is discussed, where electron-phonon coupling between FeSe and the substrate could enhance Tc to as high as 65 K or 100 K. The step-wise increment of Tc indicates that the synergic effect of carrier doping and electron-phonon coupling plays a critical role in tuning the electronic structure and superconductivity in FeSe-based superconductors.

The flow of an upper shear-driven Newtonian fluid above an otherwise still non-Newtonian fluid is considered. The lower fluid is modelled as a generalized Newtonian fluid and set into motion by interfacial shear. By means of similarity transformations, the governing partial differential equations for the two-fluid problem transform exactly into two sets of ordinary differential equations coupled only at the interface. The successful transformation of the two-fluid problem is applied to the particular case when the lower fluid obeys power-law rheology. The resulting three-parameter problem is solved numerically for some different parameter combinations by means of a direct integration approach with the density ratio fixed to unity. We observed that the interfacial velocities decreased with increasing values of the power-law index n in the range from 0.6 to 1.4 whereas the shear-induced motion of the lower fluid penetrates far deeper into a shear-thinning ( n < 1) than into a shear-thickening ( n > 1) fluid. This phenomenon is ascribed to a corresponding increase of the non-linear viscosity function with lower n-values. [ABSTRACT FROM AUTHOR]

Elaborate engineering of heterostructure and composition to regulate the electroactivities remains a pronounced challenge. Herein, a self-supported 2D/2D heterostructure monolith is constructed by interlinked FeCo-hydroxides nanosheets tightly interlacing with aligned Cu 0.76 Co 2.24 O 4 nanoplates. Due to the well-defined hierarchical nanoarrays and desirable interfacial coupling, the monolithic catalyst can guarantee the rapid charge transfer and mass transport pathways for accelerated surface kinetics, leading to manifestly improved electroactivities and stability toward trifunctional catalysis. Both experimental and theoretical calculations unravel the enriched multimetal active sites for intermediates adsorption and the synergistic interplay of the heterostructure to achieve enhanced catalytic efficiency. Consequently, the heterostructure catalyst contributes to high-performance rechargeable/flexible all-solid-stated Zn-air batteries and water electrolyzer with an ultralow potential of 1.51 V. Moreover, self-powered water splitting system driven by flexible Zn-air batteries delivers a high H 2 generation rate. This cost-effective heterostructure monolith could open an intriguing avenue for advancing all-in-one films toward portable energy conversion/storage. [Display omitted] • A self-supported 2D/2D heterostructure monolith with rich multi-metal active sites is constructed from CuCo-oxides. • The monolithic catalyst exhibits superior multifunctional activities for HER/OER/ORR. • Rechargeable ZABs obtain high specific energy and excellent cycling stability for 400 h. • The overall water splitting cell delivers an ultralow potential of 1.51 V to achieve 10 mA cm−2. • Self-powered water splitting system driven by flexible ZABs is developed for H 2 production. [ABSTRACT FROM AUTHOR]

The interfacial coupling in epitaxially grown bilayers composed of paramagnetic CaIrO 3 and ferromagnetic LaMnO 3 bilayers has been shown to give rise to an unexpected exchange bias effect. Systematic magnetic measurements ascribe this effect to the existence of an interfacial spin-cluster-like state in the bilayers. Furthermore, by tuning the epitaxial strains in the bilayers with different growth sequences, a much stronger exchange bias effect is observed in the CaIrO 3 /LaMnO 3 bilayer rather than the LaMnO 3 /CaIrO 3 bilayer, revealing the indispensable role of epitaxial strains in engineering the interfacial coupling. [ABSTRACT FROM AUTHOR]

In this study, nickel-iron sulfide (NiFeS) nanosheets were immobilized on Ti 3 C 2 MXene-decorated nickel foam (Ti 3 C 2 MXene/NF) by hydrothermal reaction (NiFeS@Ti 3 C 2 MXene/NF). The morphology of NiFeS and interactions with Ti 3 C 2 MXene resulted in electronic coupling that optimized the adsorption energies of water, protons, and oxygen atom for the HER (180 mV@20 mA cm-2) and OER (290 mV@20 mA cm-2). The NiFeS@Ti 3 C 2 MXene/NF catalyst showed good water splitting performance in an alkaline membrane water electrolyzer, yielding a current density (j) of 401 mA cm-2 at 1.85 V with 67.65 % cell efficiency, performance comparable to Pt/C||RuO 2 cells. From a commercial point of view, our electrolyzers are the best because of their low loading of catalysts (ca. 1.25 mg cm-2) and low operating temperatures (50 °C), resulting in low capital and operating costs. Our findings will aid the development of commercial green hydrogen production and offers an alternative to PEMWE. We demonstrate the excellent activity and stability of an electrolyzer system based on NiFeS@Ti 3 C 2 MXene/nickel foam self-standing anodes and cathodes. [Display omitted] • Ti 3 C 2 MXenes/NF decorated with NiFeS nanosheets to yield electrocatalyst. • Electronic coupling of NiFeS with Ti 3 C 2 MXenes promotes catalytic activity. • Current density of 20 mA cm-2 at overpotentials of 180 mV (HER) and 290 mV (OER). • Alkaline anion-exchange membrane water electrolyzer (AEMWE) tested. • AEMWE suitable for commercial production of green hydrogen. [ABSTRACT FROM AUTHOR]

This work fabricated highly flexible and piezoelectric nanofiber with coaxial and hierarchical architecture, which integrated polydopamine-modified BaTiO 3 nanowires into polymeric P(VDF-TrFE) matrix. The assembled flexible and wearable piezoelectric nanogenerator had excellent sensitivity and stability for self-powered physiological multimodal sensing. [Display omitted] • Development of organic–inorganic coaxial piezoelectric nanogenerator (PENG). • The reinforced interfacial coupling improved the piezoelectric response. • The mechanism of interfacial enhancement was deeply investigated. • High sensitivity (4.3 V N−1) and rapid response time (20.4 ms) were achieved. The relatively low sensitivity of flexible piezoelectric nanogenerators (PENG) is the most urgent problem to be solved for their applications in internet of things and artificial intelligences. To improve the piezoelectricity of polymeric fibers without discount of flexibility, BaTiO 3 nanowire (BTNW) with high aspect ratio is introduced into the piezoelectric P(VDF-TrFE) (denoted as PT) electrospun fibers to form coaxial composite nanofibers for improving the sensitivity towards external mechanical loads. To reinforce the organic–inorganic interfacial interaction for the improvement of the piezoelectric response, a nanolayer of polydopamine (PDA) is uniformly coated on the surface of BTNW (denoted as pBTNW) to form PT/pBTNW nanofibers. The introduction of 7 wt% pBTNW into the fibers significantly improves the polymeric β-phase conformation and mechanical properties, simultaneously, resulting in an optimal piezoelectric output of 18.2 V under an impact force of 5 N with excellent sensitivity of 4.3 V N−1. Through both theoretical simulation and experimental characterization, the PT/pBTNW-based PENG exhibits a higher electrical output than the equivalent nanoparticle-based PENG. The optimized PENG sensor can be used for self-powered and sensitive biomonitoring of physiological movements, finger identification and voice recognition. Overall, this work offers a reliable method for enhancing piezoelectricity of flexible polymeric nanofiber and designing high-performance PENG for wearable fabric-based sensors. [ABSTRACT FROM AUTHOR]

Continuous photocatalysis is achieved by using light-storing assisted photocatalytic composites, but little is known about the interactions between photocatalysts and long afterglow materials. g-C 3 N 4 /Sr 2 MgSi 2 O 7 :(Eu,Dy) with a sustained reaction activity was prepared by pyrolysis polymerization, and its optical-photocatalysis behaviors were studied. It was found that the light absorption ability and NO removal effect were improved, but the luminescence-afterglow performance became worse. The interface model of g-C 3 N 4 /Sr 2 MgSi 2 O 7 :(Eu,Dy) was constructed for the first time. On the basis of experimental analyses, its electronic structure and carrier transfer paths were studied by First-principles calculations, and reasons behind the changes in macro performance were revealed. The results showed that Eu 4 f electrons are difficult to return to the Eu 5d orbits after being captured by C 2p orbits, leading to the reduction of light energy radiation; the built-in electric field and energy band offsets between g-C 3 N 4 and Sr 2 MgSi 2 O 7 :(Eu,Dy) promote the transfer of photoinduced carriers, which follows a traditional type-II mechanism, resulting in enhanced photocatalytic activity and decreased luminescence-afterglow performance. This paper reveals the relationship between optical-photocatalysis behaviors and the electronic structure of g-C 3 N 4 /Sr 2 MgSi 2 O 7 :(Eu,Dy). It provides a reference for designing and optimizing light-storing assisted photocatalytic composites. • After turning off the light, the catalytic reactions of g-C 3 N 4 /Sr 2 MgSi 2 O 7 :(Eu,Dy) can continue. • Sr 2 MgSi 2 O 7 :(Eu,Dy) phosphor has the ability of photocatalytic removal of NO. • The interface model of g-C 3 N 4 /Sr 2 MgSi 2 O 7 :(Eu,Dy) was constructed for the first time. • The capture of Eu 4 f electrons by C 2p orbits leads to the reduction of light energy radiation. • The carrier transfer in g-C 3 N 4 /Sr 2 MgSi 2 O 7 :(Eu,Dy) follows a type-II mechanism. [ABSTRACT FROM AUTHOR]

In this work, composites based on polyester resin and silica sand were elaborated. Partial substitution of silica sand by waste Tetra Pak particles from discarded beverage containers was carried out, namely 1, 2, 4 and 6% by weight. As is well known, Tetra Pak packaging have six layers: four of polyethylene, one of cellulose and one of aluminum. Modified composites were irradiated with gamma rays at doses from 100 to 500 kGy in order to improve the mechanical properties of composites through a better interfacial coupling between the matrix and Tetra Pak particles caused by the irradiation process. The results shown an improvement of 15% on the compressive strength and 16% on the flexural strength, when 1% of Tetra Pak particles and irradiation dose of 100 kGy were used. Higher compressive and flexural deformation was also observed (until 34% higher); therefore a ductile material was obtained, which is not common for these kinds of composites. By increasing the irradiation dose to 200 kGy and concentration higher than 2% of waste Tetra Pak particles, mechanical properties of the composites decreased considerably. [ABSTRACT FROM AUTHOR]

Interfaces with subtle differences in atomic and electronic structures in perovskite ABO3 heterostructures often yield intriguingly different properties, yet their exact roles remain elusive. Here, we report an integrated study of unusual transport, magnetic, and structural properties of Pr0.67Sr0.33MnO3 film on SrTiO3 substrate. The variations in the out-of-plane lattice constant and BO6 octahedral rotation across the Pr0.67Sr0.33MnO3/SrTiO3 interface strongly depend on the thickness of the Pr0.67Sr0.33MnO3 film. In the 12 nm film, a new interface-sensitive ferromagnetic polaronic insulator (FI′) phase is formed during the cubic-to-tetragonal phase transition of SrTiO3, apparently due to the enhanced electron-phonon interaction and atomic disorder in the film. The transport properties of the FI′ phase in the 30 nm film are masked because of the reduced interfacial coupling and smaller interface-to-volume ratio. This work demonstrates how thickness-dependent interfacial coupling leads to the formation of a theoretically predicted ferromagnetic-polaronic insulator, as illustrated in a new phase diagram, that is otherwise ferromagnetic metal (FM) in bulk form. [ABSTRACT FROM AUTHOR]

Tin selenide (SnSe 2 ) is considered a promising anode of the lithium-ion battery because of its tunable interlayer space, abundant active sites, and high theoretical capacity. However, the low electronic conductivity and large volume variation during the charging/discharging processes inevitably result in inadequate specific capacity and inferior cyclic stability. Herein, a high-throughput wet chemical method to synthesize SnSe 2 /SnSe heterostructures is designed and used as anodes of lithium-ion batteries. The hierarchical nanoflower morphology of such heterostructures buffers the volume expansion, while the built-in electric field and metallic feature increase the charge transport capability. As expected, the superb specific capacity (≈911.4 mAh g -1 at 0.1 A g -1 ), high-rate performance, and outstanding cyclic stability are obtained in the lithium-ion batteries composed of SnSe 2 /SnSe anodes. More intriguingly, a reversible specific capacity (≈374.7 mAh g -1 at 2.5 A g -1 ) is maintained after 1000 cycles. The internal lithium storage mechanism is clarified by density functional theory (DFT) calculations and in situ characterizations. This work hereby provides a new paradigm for enhancing lithium-ion battery performances by constructing heterostructures., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

The spin-wave resonance (SWR) frequency in a ferromagnetic bilayer or triple-layer film (for bilayer or triple-layer films, including symmetric and asymmetric films) with single-ion anisotropy has been studied by using the linear spin-wave approximation and Green’s function technique. The effects of interfacial coupling, surface anisotropy, interface anisotropy, bulk anisotropy and external magnetic field on the SWR frequency have been investigated. For a ferromagnetic bilayer or triple-layer film, the SWR frequencies (for the same spin-wave modes) all increase with increasing external magnetic field, surface anisotropy, interface anisotropy and bulk anisotropy and with decreasing film thickness. As the interfacial coupling increases, the SWR frequencies of some modes increase, while the SWR frequencies of the other modes do not change. The SWR frequencies of a triple-layer film are different from those of a bilayer film and the SWR frequencies of an asymmetric film are also different from those of a symmetric film. The present results show the method to enhance and adjust the SWR frequency of ferromagnetic multi-layer films. [ABSTRACT FROM AUTHOR]

The combination of micro-scale architecture design and atomic-level interfacial engineering is of significant importance for developing advanced noble-metal-free catalysts toward efficient energy conversion. Herein, we report novel chrysalis-like hydrophilic-carbon-shell supported abundant metallic Ni nanoparticles (O-C@Ni) as a promising oxygen electrocatalyst toward electrochemical oxygen reduction reaction (ORR), which is derived from a unique organic-metal framework (MOF) based core-shell structure. Thanks to the superiorly hydrophilic affinity of oxygen-dopant-rich carbon-shell and the well-designed hollow architecture, this as-obtained O-C@Ni catalysts could deliver excellent ORR activity with a decent half-wave potential of 0.83 V and a small Tafel slope of 76 mV dec−1, comparable with commercial Pt/C catalysts and being one of the most active transition-metal based ORR electrocatalysts reported. In particular, robust methanol endurance and excellent electrocatalytic stability are evidently observed for O-C@Ni catalysts during a long-term ORR operation, superior to commercial Pt/C catalysts. X-ray absorption fine structure (XAFS) spectroscopy combined with water contact angle analyses reveals that the strong interfacial metal-support effect together with superiorly hydrophilic affinity enable O-C@Ni catalysts with promoted catalytic kinetics towards efficient ORR performance. [Display omitted] ● Novel chrysalis-like carbon with superior hydrophilic property is developed. ● These carbon-shells are derived from unique core-shell structures. ● Superior hydrophilicity and interfacial coupling promote electrochemical kinetics. ● The obtained O-C@Ni sample is promising as an active oxygen electrocatalyst. [ABSTRACT FROM AUTHOR]

Ultrathin amorphous-crystalline biphasic δ -MnO 2 / ε -Fe 2 O 3 nanosheets have been developed through tandem alkali hydrolysis and hetero-epitaxial growth protocol. The in situ reconstructed interlayer results in the ameliorated interfaces for boosting water oxidation kinetics. A proof-of-concept prototype using Zn-MnO 2 battery as power to drive δ -MnO 2 -based water splitting cell has been demonstrated. [Display omitted] • Ultrathin hetero-nanosheets have been fabricated through facile alkali hydrolysis of coordination polymers. • The hetero-epitaxial growth protocols have been proposed for the formation of hetero-nanosheets. • The hetero-nanosheets possess extraordinary alkaline OER activity and remarkable long-term stability. • The in situ interlayer reconstruction during OER has been disclosed for performance enhancement. Developing high-performance and low-cost oxygen evolution reaction (OER) electrocatalysts is critical for implementing industrial H 2 production. Herein, ultrathin Fe-Mn-O hetero-nanosheets consisting of crystalline ε -Fe 2 O 3 intercalated in amorphous Fe-doped δ -MnO 2 have been fabricated through facile alkali hydrolysis of FeMn-based coordination polymer. Abundant Mn3+ active sites and oxygen vacancies are generated in Fe-doped δ -MnO 2 layer due to in-layer/interlayer reformations, where interstitial ε -Fe 2 O 3 is engineered to reinforce stability and conductivity. The optimal 0.5Fe-Mn-O nanosheets exhibit superb activity with low overpotentials of 258 (322) mV at 10 (300) mA cm−2 for OER together with strong stability under large current density over 100 h, ranking it among the best MnO 2 -based electrocatalysts. Importantly, in situ interlayer reconstruction from ε -Fe 2 O 3 to β -FeOOH during OER has been unveiled, the evolved β -FeOOH triggers strong interfacial electronic coupling, which synergizes with oxygen vacancies and Fe3+ dopants to modulate surface electronic structure of δ -MnO 2 for intermediates adsorption. [ABSTRACT FROM AUTHOR]