Heterostructured materials, featured by two or more distinct zones with unique properties and intricate interactions at hetero-zone boundaries, showcase a remarkable strength-ductility synergistic effect for achieving superior mechanical properties surpassing their conventional homogeneous counterparts. Benefiting from the basic characteristics, such as complex composition, high configurational entropy and local distortion, multi-principal element alloys offer a fruitful playground for creating diverse heterostructures. Laser-based techniques such as laser surface treatment and laser additive manufacturing provide facile solutions with advantages such as high-energy density, rapid solidification rate, and precise control over processed zones and shapes, making them promising for the advancement of heterostructured multi-principal-element alloys. This review primarily highlights the nanoscale microstructural characteristics of various heterostructured multi-principal element alloys fabricated by laser-based techniques, along with their enhanced mechanical properties and other relevant service attributes. Moreover, it sheds light on the challenges and opportunities in harmonizing microstructural features to optimize the mechanical behavior of heterostructured multi-principal element alloys for industrial applications.

Single atom catalyst (SAC) show significant promise in electrocatalytic carbon dioxide reduction reaction (eCO₂RR) to produce valuable chemicals, representing one of the most promising ways to achieve a carbon neutral cycle. Methane is one of the many valuable products from eCO₂RR. Rational design of SAC through deliberate coordination regulation and controlled synthesis at low temperatures toward methane production remains very limited. Herein in this paper, Cu SAC with coordination of four oxygen atoms (Cu-O₄) were prepared by soaking Cu nanocrystals on carbon support in acetic acid solution at 60 °C for 12 h. The coordination structure was revealed by extended X-ray absorption fine structure spectrum and X-ray photoelectron spectroscopy. Cu-O₄ SAC demonstrates excellent activity and selectivity towards methane production, with a Faradaic efficiency (FE) of 63.0% and partial current density of 200.5 mA cm^-2. Theoretical calculation indicates less positive charge of Cu center and stronger charge delocalization in Cu-O₄ SAC than Cu-N₄ SAC due to the stronger π bonding interaction in Cu-O₄ SAC, which stabilizes the methane intermediates and lowers the potential determining step on Cu-O₄ SAC. Strong hydrogen adsorption on Cu-O₄ SAC suppresses hydrogen evolution and may favor hydrogenation of reaction intermediates to methane. The limiting potential indicates that methane is more favored on Cu-O₄ SAC than CO, methanol and formate, corroborating the high selectivity of methane production on Cu-O₄ SAC. This work highlights the importance of regulation of the coordination environment in SAC in steering products in eCO₂RR.

Noble-metal single-atom catalysts (SACs) have arisen as a research hotspot in heterogeneous catalysis resulting from superior noble-metal-atom utilization, well-defined catalytic centers, and tunable microenvironments. Recently, the advent and rise of noble-metal SACs supported by layered double hydroxides (LDHs) have injected fresh vitality and vigor into this research field. LDHs offer distinct advantages as the support of SACs, such as an ordered and adjustable crystal structure, a two-dimensional layered structure possessing a large specific surface area, facile synthesis with cost-effectiveness, and strong co-catalytic metal-support interaction between LDHs and noble-metal single atoms. In this review, we classified and comprehensively outlined the current synthesis strategies of noble-metal SACs supported by LDHs, and conducted an in-depth analysis of the specific mechanisms underlying each strategy. Subsequently, considering the critical role of the microenvironment of SACs in affecting their catalytic-related properties, we discussed the current microenvironment regulation strategies of LDH-supported noble-metal SACs. We also provide an introduction to the characterization techniques for noble-metal singe-atom sites in LDH-supported noble-metal SACs. Furthermore, we outlined the diverse applications of LDH-supported noble-metal SACs in various catalytic fields and discussed the roles played by noble-metal atoms and LDHs in relevant catalytic processes. Finally, we delineated the challenges and future research directions for the development of LDH-supported noble-metal SACs.

Developing efficient and economical electrocatalysts for hydrogen generation at high current densities is crucial for advancing energy sustainability. Herein, a self-supported hydrogen evolution reaction (HER) electrocatalyst is rationally designed and prepared on a nickel foam through a simple two-step chemical etching method, which consists of Pt quantum dots (Pt_QDs) coupled with nickel-iron layered double hydroxide (NiFe LDH) nanosheets (named Pt_QDs@NiFe LDH). The characterization results indicate that the introduction of Pt_QDs induces more oxygen vacancies, thereby optimizing the electronic structure of Pt_QDs@NiFe LDH. This modification enhances the conductivity and accelerates the adsorption/desorption kinetics of hydrogen intermediates in Pt_QDs@NiFe LDH, ultimately resulting in exceptional catalytic performance for the HER at large current densities. Specifically, Pt_QDs@NiFe LDH delivers 500 and 2000 mA·cm^-2 with remarkably low overpotentials of 92 and 252 mV, respectively, markedly outperforming commercial Pt/C (η₅₀₀ = 190 mV, η₂₀₀₀ = 436 mV). Moreover, when employing NiFe LDH precursor and the prepared Pt_QDs@NiFe LDH catalyst as the anode and cathode, respectively, in an overall water electrolysis system, only 1.66 V and 2.02 V are required to achieve 500 and 2000 mA·cm^-2, respectively, while maintaining robust stability for 200 h. This study introduces a feasible approach for developing HER electrocatalysts to achieve industrial-scale current densities.

Oxygen vacancies (V_O) play a crucial role in the stability of the ferroelectric orthorhombic (o-) phase of hafnium dioxide (HfO₂)-based thin films. However, the stability of the ferroelectric phase of HfO₂ under the action of V_O and the mechanism of ferroelectric phase transition are still unclear. In this work, V_O concentration in Hf_0.5Zr_0.5O₂ (HZO) thin films is tuned through electron beam irradiation inside a transmission electron microscope. For the crystalline HZO thin films processed through rapid thermal annealing, the increase of the V_O concentration during in situ electron beam irradiation facilitated the phase transition from the non-polar monoclinic (m-) and tetragonal (t-) phases to the polar o-phase. For the amorphous HZO thin films, the nucleation and growth process of the m- and o-phases are observed during in situ electron beam irradiation. The phase transition from m-phase to o-phase is accompanied by the evolution from tensile to compressive strain. These results help to clarify the mechanism of ferroelectric phase transition under the action of V_O, and guide the control of the ferroelectric properties and phase stability of HfO₂-based thin films.

Some transition-metal oxides such as Ca₂RuO₄, BiNiO₃, and V₂OPO₄ harbor smaller volume and higher entropy states by role sharing of the spin, charge, and orbital degrees of freedom. Effect of lattice distortions on the various charge/orbital patterns can be analyzed by d-p models with full degeneracy of the transition-metal d and oxygen 2p orbitals. Based on the mean-field analyses on the d-p models for Ca₂RuO₄, BiNiO₃ and V₂OPO₄, possible mechanisms of negative thermal expansion with charge and orbital degrees of freedom are discussed. In Ca₂RuO₄ and BiNiO₃, orbital and/or charge states are rearranged across their insulator-metal transitions, and the metallic phases with orbital and/or charge fluctuations can be stabilized at high temperatures relative to the insulating phases without them. In V₂OPO₄, the charge/orbital disordered state can keep relatively smaller volume due to orbital-dependent hybridization in the face-sharing VO₆ octahedron chain.

Flexible dielectric composites stand as a promising candidate in high-power energy storage technology, but their practical application is hindered by low energy storage density (U_e), efficiency (η), and poor thermal stability at elevated temperatures. Herein, core-shell nanoparticles using barium strontium titanate coated with cadmium sulfide (BST@CdS) are designed and incorporated into polyetherimide (PEI) matrices as fillers to fabricate nanocomposite films. The CdS on the surface of BST nanoparticles, with its moderate dielectric constant, alleviates electric field mismatch between BST nanoparticles and PEI, while also introducing additional interfacial polarization. Additionally, the electron traps formed at the CdS/PEI interface can capture free and injected electrons. These features concurrently lead to an enhanced dielectric constant, reduced dielectric loss, and suppressed leakage current density, thereby boosting the energy storage performance of nanocomposite films. Accordingly, the optimized PEI/BST@CdS nanocomposite boasts an outstanding U_e of 9.4 J cm^-3 and an η of 93.9% at 600 kV mm^-1 and 25 °C. Remarkably, even at 150 °C, it still achieves superior energy storage performance with a U_e of 4.4 J cm^-3 and an η of 90.7% at 400 kV mm^-1. This study presents a viable approach for fabricating high-performance dielectric energy storage capacitors.

Flexible thermoelectric (TE) materials and their devices have gained increasing attention due to the flexibility and lightness of flexible TE technology for low-temperature waste heat collection. In recent decades, various efforts have been devoted to the impressive efficiency of flexible TE technology including the synthesis, design, and integration of flexible TE generators. In this regard, the urgent need for eco-friendly, stable, and durable power sources motivates the booming market for integrated electronics. This review comprehensively summarizes the state-of-the-art development of flexible TE materials, device types, fabrication techniques, and the fundamentals behind their applications. In addition, the employed methods for moderate physical properties including theoretical analysis, experimental prospects, and importantly the challenges of flexible TEs are introduced. Moreover, we summarized the applications of flexible TEs in textiles, wearable electronics, waste heat utilization, and their applications in sensors, the Internet of Things, health monitoring, etc. We believe that this review addresses the current research challenges and their future directions to the researchers for choosing potential materials to explore flexible TE technology.

Ultrawide bandgap (UWBG) semiconductors, with bandgaps exceeding 3.4 eV of gallium nitride, offer the potential to overcome the limitations of conventional semiconductors and drive innovations in electronics and photovoltaics. However, discovering such materials remains a huge challenge due to the prohibitive cost of trial-and-error-based experiments and the complexity of cutting-edge quantum mechanical approaches. Here, we develop the Multistage Ensemble Learning Rapid Screening Network (MELRSNet), a data-driven hierarchical machine learning framework integrated with high-throughput first-principles calculations, designed for swift identification of UWBG semiconductors. Trained on the Materials Project dataset, MELRSNet utilizes elemental and structural features to classify, regress, and validate potential candidates. Its efficacy is underscored by the accurate prediction of bandgaps in UWBG oxides and the revelation of metric-bandgap relationships, aligning closely with first-principles calculations. Furthermore, MELRSNet's reliability is bolstered through the identification of eight novel ternary oxide compounds, derived from monoclinic hafnium oxide crystals, exhibiting high stability, desirable band gaps, and strong ultraviolet light absorption, marking them promising candidates for lab synthesis and subsequent applications. MELRSNet not only streamlines the discovery of UWBG semiconductors but also paves the way for high-throughput computational screening of other functional materials.

A multilayer hard ceramic layer coated Ti composite was prepared through plasma electrolytic oxidation (PEO) combined with microwave hydrothermal (MH) treatment. After PEO and PEO-MH treatment, the in-situ formed ceramic coating significantly affected the deformation behavior of the Ti matrix, and the deformed slip bands appeared at a greater deformation on the Ti matrix during the tensile process; the deformation texture was also observed. Additionally, compared to pure Ti, the tensile strength, yield strength and elongation of the PEO and PEO-MH exhibited slight increases. The presence of the hard ceramic layer effectively inhibited crack propagation at the substrate/coating interface. Moreover, the self-interlocking effect at the coating/substrate interface generated by the corrosion grooves further optimized the stress distribution at the coating/substrate interface, and the ratio of amorphous to crystalline phases also played a crucial role in adjusting the deformation behavior of the Ti matrix. After MH treatment, the PEO-MH possessed more titania nanocrystalline clusters and a multilayer structure, promoting more uniform deformation of the Ti composite. Notably, an intriguing crystalline-to-amorphous phase transformation process was observed through in situ tensile tests and molecular dynamics simulation. This phase change, which occurs at the crack tip, effectively alleviates the stress concentration phenomenon, resulting in lattice distortion that ultimately enhances the strength of the Ti composite. This research provides crucial insights into the application of Ti composite in high-load environments and establishes a solid foundation for their broader utilization in the future.

Among the reported non-precious-metal catalysts, metal-nitrogen-carbon (M-N-C) catalysts have emerged as a research cornerstone in the field of electrocatalysis, showcasing unparalleled activity in oxygen reduction reactions that rivals or even exceeds that of commercial Pt catalysts. Despite boasting high atom utilization and adjustable effective activity centers, M-N-C catalysts suffer from inadequate long-term stability under high-pressure and harshly acidic conditions within proton exchange membrane fuel cells (PEMFCs). This drawback poses a significant challenge that critically limits their potential for widespread applications. From this perspective, we commence by delineating the pivotal strategies to augment the performance of M-N-C catalysts at the microscopic level, including the tuning of the intrinsic activity of individual active sites and the manipulation of their quantity. Furthermore, we delve into the benefits derived from the synergistic effects unleashed by the incorporation of multi-component active sites. At the mesoscopic level, this perspective engages with the design principles aimed at enhancing the activity and stability of M-N-C catalysts within the intricate three-phase boundary of PEMFCs. Ultimately, we prospect the opportunities and challenges facing the future evolution of M-N-C catalysts, with the aim of offering comprehensive guidance for the design and advancement of highly stable M-N-C catalysts tailored for PEMFC applications.

High-entropy alloys in which the face-centered cubic structure is dominant cannot meet practical engineering application requirements due to their insufficient strength. Traditional strengthening methods can improve strength of materials, but they inevitably lead to decreased ductility. In this work, mechanical properties of a face-centered cubic-structured FeMnCoCrCu high-entropy alloy were improved by doping a substantial amount of carbon and employing a processing route that combines cold rolling and annealing. A dual-heterostructure characterized by both bimodal grain-size distribution and non-uniform distribution of nanoscale precipitates was constructed. The average grain sizes were 21.6 and 5.9 μm for the coarse and fine grains, accounting for 56.6% and 43.4% of the material, respectively. On the other hand, the finer M₂₃C₆ precipitates in the grain interior had an average size of 73.1 nm, constituting 3.4% of the coarse-grained region and 10.7% of the fine-grained region. The larger M₂₃C₆ precipitates at grain boundaries had an average size of 182.4 nm, with an overall volume fraction of 1.5%. This heterogeneous microstructure endowed the alloy with superior strength and work-hardening capacity compared to the carbon-free alloy. The yield and tensile strengths reached 500 MPa and 979 MPa, respectively, while maintaining a uniform elongation of 42%. This study not only identifies the origin of strengthening and micromechanism of plastic deformation in the carbon-alloyed dual-heterostructured alloy but also elucidates the formation of the specified microstructure. The findings provide theoretical guidance for developing advanced alloys with both high strength and good ductility.

The cyclability and reversibility of aqueous zinc-ion batteries (AZIBs) are severely hampered by the safety concerns arising from the Zn dendrite growth. Therefore, a stable anode with inhibited dendrites and side reactions is crucial for AZIBs. Herein, we utilized methyl acetoacetate (MA) as an additive to prevent dendrite growth and enable highly reversible Zn anodes. Benefiting from the nucleophilic groups (carbonyl groups) in MA, MA molecules can preferentially adsorb on the anode/electrolyte interface (AEI), forming a molecular protective layer. Such MA layers can not only regulate the migration and deposition of zinc ions, but also inhibit side reactions induced by the decomposition of free H₂O molecules at AEI. Therefore, the symmetric cell with the addition of MA achieves a long-term cycling stability of 1,500 h at 2 mA cm^-2 with a capacity of 2 mAh cm^-2. In addition, the Zn//NVO full cell using MA-contained electrolyte demonstrates a high specific capacity (138.4 mAh g^-1) with an outstanding capacity retention (92.8% after 600 cycles) at 1 A g^-1. This work provides a principle for the use of ester-based additives with nucleophilic groups to suppress Zn dendrite growth for highly durable zinc metal anodes.

Over two decades have passed since the successful exfoliation of graphene, which initiated the exploration of two-dimensional (2D) materials. Since then, this vibrant group has expanded to encompass a variety of new materials. Among these, molybdenum (Mo)-based oxides with 2D structures have attracted growing interest. Due to their remarkable properties, 2D Mo-based oxides have ensured their prominent position in cutting-edge scientific domains, including energy applications, catalysis and electronic devices. This review systematically examines recent advancements in the synthesis, structural regulation, and applications of 2D Mo-based oxides. Firstly, a detailed overview of various synthesis techniques is given, including but not limited to hydrothermal methods, physical vapor deposition, and chemical vapor deposition, enabling the production of high-quality 2D Mo-based oxides. Subsequently, strategies are presented for structural regulation through doping, interface engineering, and interlayer tuning. Finally, recent application developments in energy conversion and storage, catalysis, sensing, and optoelectronic devices are highlighted. Furthermore, an outlook on potential future trends is provided at the conclusion of the review, aiming to advance the practical deployment of 2D Mo-based oxides in emerging technologies.

Magnesium (Mg)-based metallic glasses have emerged as a promising class of biomaterials for various biomedical applications due to their unique properties, such as high strength-to-weight ratio, good biocompatibility and biodegradability. The development of Mg-based metallic glass scaffolds is of particular interest for tissue engineering and regenerative medicine applications. However, the rate of biodegradability of the materials is not well controlled and requires extensive research for efficient tissue/bone regeneration. This review provides a comprehensive overview of the recent advancements in the development of Mg-based metallic glass scaffolds and their tuneable biodegradability with different compositions and thin film coatings. It discusses the structural and biological properties, mechanical and biodegradation behavior, and various fabrication techniques employed to produce Mg-based bulk metallic glass scaffolds. Furthermore, the review explores surface modification of permanent implants with Mg-based thin film biodegradable metallic glasses to simulate tissue regeneration on the implants. Optimization of scaffold design to increase tissue growth and healing by understanding the complex interactions between the scaffold and biological tissues and predicting the long-term implant behavior using computational models are reviewed. The challenges and future research directions in this field are also discussed, providing insights into the potential of Mg-based metallic glass scaffolds for various biomedical applications, including bone tissue engineering, wound healing, and cardiovascular implants.

The proton exchange membrane (PEM) fuel cell (FC) represents a new and efficient form of clean energy, offering unique advantages such as high power density and long service life. It is considered to be a promising new generation technology for addressing energy crises and environmental issues. However, the commercially available Nafion PEM continues to encounter issues such as insufficient water retention and elevated costs. It is imperative to develop PEM materials that exhibit high proton conductivity and superior stability. The optimal PEM material exhibits high proton conductivity, high chemical stability, superior mechanical properties, easy preparation, and low cost. These materials can be incorporated into H₂/O₂ fuel cells to enhance the practical application of metal-organic framework (MOF)-based proton-conductive materials in electrochemical devices. In recent years, MOFs have attracted considerable attention in the field of proton conduction owing to their tunable structure and high crystallinity. The incorporation of MOFs into polymer matrices has been shown to enhance the proton transfer path within the membrane, providing valuable insights into the mechanism of proton transfer in hybrid membranes. This review summarizes recent research on the advantages of using MOF materials for proton transfer and their composite membranes. It is crucial to develop PEM materials that exhibit high proton conductivity and outstanding stability.

At present, using biomass materials to modify graphene oxide (GO) to enhance the anticorrosion performance of coatings meets the requirements of future sustainable development. In order to endow lignin/GO coatings with self-healing function to reduce maintenance costs and avoid accidents caused by material corrosion failure, this work utilized electrostatic interactions to load zinc ions onto lignin/GO (Zn@LGO). Experimental results indicated that the cured coating exhibited both self-healing anticorrosion and photothermal conversion properties. When the content of Zn@LGO was 0.4 wt%, the surface temperature of the cured coating rose to 139.2 °C after 180 s of near-infrared radiation. The cured coating was left for 100 days in salt water, the Z_0.01Hz value of coating VER-3 was up to 1.3 × 10⁹ Ω cm², which was two orders of magnitude higher than that of pure resin coating, and fewer corrosion products were observed on the metal surface. The scratch test showed that the damaged coating was soaked in 3.5 wt% sodium chloride for 72 h; the charge transfer impedance of coating VER-3 was 2.61 × 10⁴ Ω cm², which was one order of magnitude higher than that of pure resin coating. This was mainly because during metal corrosion, the hydroxide generated by the combination of hydroxide ions at the cathode and zinc ions covered the damaged area of cured coating, hindering the penetration of the corrosive medium. All in all, this research promoted the application of lignin, and also provided a reference for the design of composite coatings with both photothermal conversion and self-healing anticorrosion properties.

Microstructured surfaces play a pivotal role in fluid manipulation, leveraging their unique chemical and physical properties to exert precise control over fluid behavior. These structures significantly influence fluid wettability, adhesion, mobility, and dynamic behavior, offering broad prospects in microfluidics, biomedicine, energy, materials science, and other fields. Despite existing challenges related to stability, wear resistance and manufacturing processes, the field of microstructured fluid control holds substantial promise for future advancements. This review surveys the latest advancements in microstructured surface fluid control technology, spanning from the design and fabrication of microstructured surfaces to their applications and deployment across various domains. We initially explore the design principles and fabrication methods of microstructured surfaces, and delve into the strategies employed for fluid manipulation by modulating surface chemistry and morphography. Additionally, the applications of microstructured surfaces in microfluidic control, biomedical engineering, energy harvesting, and environmental monitoring are further emphasized and discussed, showcasing the significant contributions to technological innovation. Finally, the current technical challenges and potential applications of liquid manipulation on microstructured surfaces are featured, and their prospects are discussed based on the current development.

The existence of biomass materials as the only renewable carbon source is an extremely important resource in the realm of modern energy and materials science. Biomass-derived carbon composites (BDCCs), with their unique advantages and applications, such as wide sources, low cost, high carbon content and tunable structure, have promoted progress and innovation in several technological fields and played an indispensable part in mitigating environmental pollution and promoting sustainable development in energy storage and conversion applications. Phase change materials (PCMs), which possess latent heat storage and release properties, have been widely applied in the field of energy storage and utilization. Nonetheless, several obstacles limit the application of PCMs, including the occurrence of leakage during operation and the relatively low thermal conductivity. The porous structure of BDCCs enhances the thermal conductivity of PCMs and effectively prevents leakage. Consequently, there has been growing interest among researchers in BDCCs/PCMs. Nevertheless, there is a paucity of literature providing a comprehensive and detailed introduction to BDCCs and their applications in PCMs. On this basis, this review will provide an overview of the feedstock classes and synthesis methods based on recent research advances, followed by an investigation of the potential functional applications of BDCCs. Ultimately, this paper provides a targeted summary of the development advantages and challenging opportunities of BDCCs in functional applications based on the current state of research and emerging needs, providing constructive references for the future development and efficient utilization of BDCCs/PCMs.

Graphene, with its two-dimensional structure, offers high mechanical flexibility and excellent conductivity, but its tendency to stack and aggregate in practical applications reduces the effective surface area, resulting in rapid capacity degradation. To overcome this, we in situ grow rod-like Co₃S₄ structures on graphene oxide graphene oxide (rGO), forming a highly conductive and mechanically stable composite. The Co₃S₄ nanoparticles serve as active sites for redox reactions, significantly improving the specific capacitance, while the rGO matrix enhances electron transport and mitigates the issues of volume expansion during charge/discharge cycles. The Co₃S₄/rGO composite is synthesized via a two-step hydrothermal process, and the effects of sulfuration temperature and time on electrochemical performance are systematically explored. The results show that the Co₃S₄/rGO-160-8 composite, synthesized at 160 °C for eight hours, achieves a specific capacitance of 1442.5 F·g^-1 at 1 A·g^-1 and exhibits a capacity retention of 93.3% after 5000 cycles at 4 A·g^-1. Furthermore, the Co₃S₄/rGO-160-8//activated carbon asymmetric supercapacitor delivers an energy density of 47.0 Wh·kg^-1 at 749.8 W·kg^-1 power density, with only an 8.9% capacity loss after 5000 cycles, demonstrating excellent cycling stability. This novel composite material offers a promising approach for high-performance supercapacitors, balancing high energy density, excellent rate performance, and long-term stability.