Lignin, one of the most abundant and renewable components of biomass, represents a promising feedstock for sustainable biofuel production. Photocatalytic conversion offers an efficient, environmentally benign, and mild route for lignin depolymerization. Transition-metal-based photocatalysts, in particular, enable precise modulation of photogenerated charge carriers and the creation of highly active catalytic sites, thereby facilitating selective lignin transformation while preserving its valuable aromatic motifs. Despite rapid advances, comprehensive reviews on transition metal-based photocatalysts for lignin-to-fuel conversion remain limited. This review systematically summarizes recent progress in transition-metal-based photocatalytic lignin valorization for both gaseous fuels and liquid fuel precursors. We analyze the key bond-cleavage mechanisms using lignin model compounds, uncovering structure-activity relationships between transition-metal catalysts design and lignin depolymerization behavior, and highlight the current challenges hindering practical applications. Furthermore, the synergistic interactions between photocatalytic routes to liquid and gaseous fuels are discussed. Finally, strategies for upgrading lignin-derived intermediates into usable fuels are evaluated, with attention to their technical, economic, and environmental feasibility. Overall, this review offers new insights and theoretical guidance for advancing transition metal-based photocatalytic systems toward efficient and sustainable lignin-to-biofuel conversion.

Ultrafast erbium-doped fiber lasers (EDFLs) operating at 1.5 mu m were essential for advanced photonic applications. Beyond merely pursuing the shortest pulse width, developing EDFLs with robust environmental adaptability and reliable operation under practical conditions has become a critical challenge for real-world deployment. We reported an erbium-doped fiber laser based on a novel carbon nanotube saturable absorber (CNT-SA), which achieved self-starting mode-locking at a pump power as low as 40 mW and, more importantly, exhibited exceptional robustness against cavity dispersion variations-a critical yet often overlooked attribute for practical ultrafast laser sources. The CNT-SA, engineered via hydrothermal synthesis using an AFI zeolite template, not only provided the laser with a low threshold advantage but, more importantly, its broadband response and ultrafast recovery dynamics enabled the laser to maintain stable mode-locked operation even when the cavity length was actively adjusted by over 40 m, with a spectral shift of less than 4 nm. This ability to combine low-power self-starting with superior dispersion tolerance had not been reported in previous studies, offering an ideal solution for applications requiring long cavities or environmental stability, such as distributed sensing and high-energy pulse accumulation systems. This work, therefore, prioritizes the balance among low threshold, high stability, and strong dispersion tolerance, aiming to bridge the gap between laboratory performance benchmarks and application-ready ultrafast sources.

For the next generation of lithium metal batteries of high energy density and high-power density, the protection of cathodes is vital, which requires a uniform cathode-electrolyte interphase (CEI) layer with an excellent mechanical strength upon cycling. Here, we introduce closo-type borohydride Li2B12H12 as an effective electrolyte additive, via a synergistic decomposition that [B12H12]2- and [PF6]- of commercial electrolytes undergo at voltages ∼3.3 V, constructing a CEI layer rich in both fluorides and borides. The modulated CEI layer is as thin as ∼10 nm with a high Young's modulus of 8.77 GPa. This CEI enhances the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode, as well as other ultrahigh-voltage cathodes like Li-rich Mn-based (LRMO) cathodes. The Li||LRMO battery not only reaches an outstanding rate performance at 10 C, but also reaches an energy density of 392 Wh kg-1 in a 3 Ah-class pouch cell. This synergistic decomposition strategy of the closo-type borohydride additive effectively provides a reference for the modulation of an ultrathin and strong CEI, balancing both energy density and power density of the battery.

Zinc-air batteries are considered promising candidates for the next generation of batteries due to their significant advantages in theoretical specific capacity, safety, and environmental friendliness. The combination of gel polymer electrolytes and zinc-air batteries further expands future energy storage applications. However, traditional alkaline gel zinc-air batteries are usually constructed by post-stacking methods, and their poor interfacial contact and weakened long-term durability in the ambient air hinders practical applications. Here, we synthesized a non-alkaline gel electrolyte with a liquid-solid phase transition mechanism utilizing agar, and constructed an integrated gel zinc-air battery by direct injection and encapsulation methods. This strategy realizes the integrated assembly of non-alkaline gel zinc-air full batteries, thereby obtaining all-round high stability. The agar gel electrolyte endows the battery with outstanding performance, including a high output specific capacity (706 mAh g Zn-1), a long discharge duration (270 h at 0.1 mA cm(-2)), and a significant operational life (850 h at 0.2 mA cm(-2)). Importantly, the integrated zinc-air pouch battery can achieve a high zinc utilization rate of over 80% in various discharge states and exhibit satisfactory cycling stability (>200 h at 0.1 mA cm(-2)). This technology alleviates the current challenges of gel zinc batteries, and highlights the direction for the development of non-alkaline gel zinc-air full batteries.

Mg-based hydrides are highly promising solid-state hydrogen storage materials due to their high theoretical capacity, natural abundance, and low cost. However, their widespread implementation is constrained by inherent thermodynamic stability, sluggish kinetics, and progressive capacity fade during cycling. This review provides a comprehensive assessment of three primary modification strategies: alloying, catalytic modification, and nanoengineering. Alloying strategies, encompassing both intermetallic and disproportionation-type alloys, regulate thermodynamic stability by weakening Mg─H interactions through electronic structure modulation and lattice distortion while improving kinetics by inducing grain refinement and establishing high-density phase boundaries. Catalytic modification employs transition metals, metal oxides, and MXenes to establish multivalent active centers that accelerate reaction kinetics by facilitating hydrogen interfacial transport, lowering activation barriers via the dissociation and migration of atomic hydrogen, and destabilizing Mg─H bonds through interfacial electron transfer, while providing continuous diffusion channels and inducing heterogeneous nucleation. Nanoengineering strategies are able to thermodynamically destabilize the hydride phase through surface energy effects, shorten hydrogen diffusion paths, and increase accessible active sites for efficient hydrogen storage. By correlating these mechanisms, this work outlines prospective research directions, such as the development of integrated multi-mechanism systems, stable catalytic materials, and external field-assisted techniques to achieve hydrogen storage at near-room temperature.

Long-duration energy storage is critical for integrating renewable energy, yet few technologies simultaneously achieve low cost, long cycle life and high safety. Here we report a flowing Zn slurry (FZS) battery in which nanoscale Zn particles dispersed within a conductive network undergo reversible Zn/Zn2+ redox conversion with enhanced stability. Ligand-assisted confinement coordinates onto Zn nanoparticle surfaces, suppressing excessive Zn growth and parasitic reactions, enabling uniform, monodisperse Zn nanocrystal deposition throughout the slurry. In FZS | |Cu asymmetric cells at 8 mA cm-2, it achieves a Coulombic efficiency of 99.94%, whereas symmetric cells operate reversibly for 5,128 h at 22.5 mA cm-2, 135 mAh cm-2 under continuous flow. Extending from these results, FZS | |MnO2 full cells retain 81.1% capacity after 5,500 cycles at 10 A g-1, and FZS | | O2 full cells deliver 1.65 Ah over 100 h at 1.35 mA cm-2. This work demonstrates the viability of FZS for long-duration energy storage, providing a framework for scalable, stable metal-slurry-based flow battery systems.

ABSTRACT Dodecahydro‐N‐ethylcarbazole (12H‐NEC) is a promising liquid organic hydrogen carrier (LOHC), yet its practical application is still constrained by slow dehydrogenation kinetics and extreme reliance on external heating even over most effective Pd‐based catalysts. Here we identify that the hydrogen removal step with a high barrier is the precise kinetic bottleneck of 12H‐NEC dehydrogenation, which remains underexplored. To effectively overcome this limitation, we report a light‐activated dual‐site hydrogen removal pathway using Pd nanoparticles supported on defective N‐doped TiO 2 . Under irradiation, charge transfer from the support to Pd weakens Pd‐H interactions, while accumulated holes on the support promote hydrogen spillover to Ti defect sites, generating weakened Ti‐H species alongside Pd‐H. This thereby initiates a new hydrogen formation dual‐site pathway by combining Pd‐H and Ti‐H with an overall dehydrogenation barrier of 0.46 eV only, 0.74 eV lower than the conventional thermal Pd‐localized pathway, resulting in a 42‐fold higher H 2 release rate relative to dark conditions at 140°C. Even under concentrated natural sunlight without external heating, near‐complete dehydrogenation with a capacity of 5.65 wt.% H 2 within 1 h is achieved from 12H‐NEC. This work charts a promising course for practical hydrogen storage applications of LOHCs without secondary energy input.

Silicon (Si) is a premier candidate for high-energy-density lithium-ion batteries due to its exceptional theoretical capacity, low lithiation potential, and high abundance. However, the severe volume expansion of silicon during lithiation/de-lithiation leads to particle pulverization and electrical isolation, resulting in the accumulation of inactive “dead silicon” with subsequent rapid capacity decay. This issue will be significantly exacerbated in all-solid-state batteries (ASSBs) when using microscale silicon (micro-Si) anodes, where the mechanical mismatch and contact loss are further intensified. Herein, we report a smart binder based on gallium nitride (GaN) integrated into silicon electrodes, where GaN undergoes an irreversible reaction to form in situ liquid gallium (Ga) and lithium nitride Li3N. This smart binder GaN establishes a synergistic environment where the self-healing liquid metal maintains micro-Si adhesion and the Li3N provides rapid ion transport, collectively sustaining a stable, localized ion-electron conductive framework during cycling. In contrast to the rapid decay of capacity in half-cells with Si electrode after 20 cycles, micro-Si electrode with the aid of GaN delivered excellent cycling stability at 0.1C, retaining a specific capacity exceeding 2100 mAh g−1 after 100 cycles.

Electrocatalytic CO2 reduction reaction (CO2RR) is crucial for carbon recycling and neutrality, yet its efficiency is hampered by the high-energy oxygen evolution reaction (OER). Paired electrolysis has emerged as a promising strategy to simultaneously lower energy consumption and enhance product value by replacing OER with value-added organic oxidation reactions. This review summarizes recent advances in CO2RR coupled with alternative anode reactions. It begins with CO2RR mechanisms and product control strategies, analyzing influences of catalyst properties, electrolyte environments, and reaction conditions. Then, the core integration strategies of paired electrolysis systems are elaborated in terms of selection and integration of anode reaction, thermodynamic/kinetic matching, electron-proton transfer synergy, pH compatibility, system stability, and optimal reactor design. A detailed review of the application of heterogeneous electrocatalyst pairs and homogeneous electrocatalyst pairs in coupled systems from the perspective of electrode material design is presented, and the relationship sbetween their structure-activity and synergistic mechanism is also discussed. Finally, the existing technical problems in this field are summarized, including the bottlenecks of product value addition, system energy consumption, system stability, and large-scale integration. This review provides theoretical guidance and technical reference for designing an efficient system of paired electrolysis in the future.

This study describes a fully organic, biomass-derived donor-acceptor (D-A) photocatalyst in which perylene diimide (PDI) units assembled on chitosan (CS) form a it-conjugated supramolecular network with g-C3N4 (CN). XANES, KPFM, fs-TAS, and theoretical calculations collectively disclose that the engineered D-A architecture of CN@PDI-CS significantly strengthens visible light absorption (with the absorption edge red-shifted to 750 nm), enhances interfacial charge transfer, and reinforces redox capabilities. Furthermore, the extensive it-electron delocalization within CN@PDI-CS promotes rapid transport of photogenerated electrons, enabling efficient generation of reactive free radicals, achieving 96.23% degradation of pesticide imidacloprid, with a reaction rate constant (0.095 min-1) 3.0 times and 2.5 times greater than those of PDI-CS and CN, respectively. In situ spectroscopy and control experiments identify superoxide radicals (center dot O2-) and singlet oxygen (1O2) as dominant reactive species, and the degradation pathway is systematically elucidated by combined experimental-theoretical analysis. Comprehensive toxicity evaluations further confirm the high purification efficiency and environmental benignity of this system. This work demonstrates a rational D-A modulation strategy for designing high-performance biomass-derived photocatalysts, establishing a sustainable approach for efficient water purification that advances beyond conventional photocatalytic systems by simultaneously addressing broadspectrum absorption, interfacial compatibility, and directional charge transport challenges.

Precious metals such as Pt are favoured as catalysts for the hydrogen evolution reaction (HER) due to their excellent catalytic activity. However, the scarcity and high cost of precious metals have prompted researchers to explore cheaper alternatives such as Cu. Nevertheless, Cu shows poor catalytic performance due to weak binding with intermediates. Here the catalytic activity of pure Cu is activated via electroreduction-driven modification of the local structure, achieving a HER catalytic performance superior to commercial Pt/C catalysts for working current densities greater than 100 mA cm−2 in acid electrolyte. Activation involved two steps. First, polycrystalline Cu2O nanoparticles were prepared via pulsed laser ablation, resulting in grain boundaries within the Cu2O particles as observed using electron microscopy. Next, the Cu2O particles were electroreduced to pure Cu, inducing the formation of distorted nanotwins and edge dislocations. These local structures induce high lattice strain and decrease the Cu coordination number, enhancing the interaction between Cu and intermediates—as calculated using density functional theory—leading to the excellent catalytic activity and durability of the catalyst. Our observations show that low-cost pure Cu can be a promising HER catalyst for large-scale industrial applications. Low-cost Cu catalysts for the hydrogen evolution reaction (HER) can transform industrial water electrolysis, but pure Cu typically exhibits a negligible HER. Here, combining pulsed laser ablation and subsequent electroreduction, Cu nanotwins form that enable the HER at an overpotential of 301 mV, with 125 h of stable operation at a current density of 500 mA cm−2.

Conversion electrodes typically have high theoretical specific capacity, but mostly suffer large structural changes during charge/discharge and result in poor cycling stability. The optimization of the polycrystalline materials is the mostly used strategy, however, these polycrystalline materials are intrinsically vulnerable to grain-boundary (intergranular) fracture caused by the anisotropic volume change during sodiation/desodiation, resulting in rapid impedance growth and capacity decay. Herein, we propose an alternative pathway to design single-crystal materials as potential conversion anodes. As an example, SnO2 with different crystallinities is successfully synthesized via solvothermal methods and compared to determine the implications of different crystallinity for the electrochemical properties of conversion anodes. It is demonstrated that the single-crystal SnO2 not only has faster Na+ diffusion dynamics but also maintains structural stability via topotactic reaction. Further optimization of the electron conduction and structural robustness is realized by uniformly covering a graphitic carbon shell on the surface of singlecrystal SnO2 nanosheets. The modified single-crystal SnO2 exhibits a high reversible capacity of 436.2 mA h g-1 and maintains a high capacity of 257.1 mA h g-1 and remarkable capacity retention of about 98.9 % after 90 0 0 cycles at 50 0 0 mA g-1 . The deep understandings of the topotactic reaction in single crystal conversion anode in this work provide a theoretical foundation and new direction for further developing electrode materials with excellent electrochemical performance, especially high rate capabilities, and long cyclability. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Magnesium hydride (MgH2) is a promising hydrogen storage material for its high hydrogen capacity of 7.6 wt.%. However, the further application is severely hampered by the sluggish reaction kinetics and stable thermodynamics. Introducing catalysts is an effective method to improve the reaction rate, but the catalytic activity tends to decrease with an increasing number of reaction cycles, due to the highly reductive Mg and H species. Herein, the spring effect has been observed in the P doped Li3VO4, in which both V & horbar;P and V & horbar;V bonds undergo compression and elongation during hydrogen absorption and desorption, respectively. Such a unique self-regulation spring effect not only improves the reaction kinetics of MgH2, but also maintains the high activity of P doped Li3VO4, thereby ensuring the hydrogen capacity of MgH2 even after 100 loops. This spring effect of chemical bonding, stretched-recovered-stretched with the motion between the highly reductive Mg and H species, will provide insight into catalyst design for hydrogen-related industries.

Self‐healing anodes, enabled by liquid metals, stand out among alkali‐ion storage materials due to their spontaneous repairing capability. Nevertheless, a fundamental understanding of the underlying self‐healing mechanism, particularly from the perspective of stress evolution, remains elusive. Herein, a self‐derived stress‐release phase strategy is proposed to elucidate the intrinsic role of liquid gallium (Ga) in achieving self‐healing behavior and high‐performance sodium storage. Specifically, Ga 2 Se 3 is selected as a model system, where liquid Ga is self‐derived during the conversion reaction, as confirmed by theoretical calculations and in situ XRD analysis. Abnormal peak shifts of Na 2 Se observed during cycling are explained by a unit‐cell “breathing” mechanism induced by the liquid Ga, which functions as a stress‐release phase. This process not only heals cracks but also alleviates misfit strains, thereby mitigating structural degradation and enabling long‐term electrochemical stability. As anticipated, Ga 2 Se 3 demonstrates superior cycling performance in both half (≈200 mAh g −1 at 10 A g −1 ) and full cells (a high‐capacity retention of 91.5% after 150 cycles), highlighting its potential for practical sodium‐ion batteries. The findings provide direct evidence that self‐derived stress‐release phases are key to self‐healing electrodes, offering a new paradigm for designing high‐performance sodium storage systems.

The rapid development of energy storage systems with high energy density and safety is crucial to meet the increasing demand for renewable energy storage and portable electronics. Li/Mg‐based hydrides have gained significant attention for both hydrogen and lithium storage due to their lightweight composition and high hydrogen content. Recent advancements in catalytic design, thermodynamic tuning, nanostructuring, and external field‐driven methods have markedly enhanced their hydrogen storage performance. For lithium storage, strategies to optimize ion transport and structural stability have improved ionic conductivity, reaction kinetics, and reversibility, enabling the development of high‐performance energy storage systems. This review provides a detailed analysis of the progress, challenges, and opportunities in Li/Mg‐based hydrides. It emphasizes breakthroughs in material modification, innovative synthesis methods, and performance optimization, showcasing their potential in hydrogen and lithium storage applications. Key challenges include balancing catalytic and thermodynamic regulation and exploring new driving methods for hydrogen storage, while enhancing ionic conductivity and refining doping techniques for lithium storage remain critical. By integrating insights into their dual roles, this work lays a strong foundation for the continued development and application of Li/Mg‐based hydrides in next‐generation energy storage technologies.

The electrolyte-electrode interface serves as the foundation for a myriad of chemical and physical processes. In battery chemistry, the formation of a well-known solid-electrolyte interphase (SEI) plays a pivotal role in ensuring the reversible operations of rechargeable lithium-ion batteries (LIBs)1,2. However, characterizing the precise chemical composition of the low crystallinity and highly sensitive SEI presents a formidable challenge3. Here, taking lithium fluoride (LiF)-a widely studied and considered crucial SEI component4-7-as an example, we use 19F solid-state nuclear magnetic resonance (NMR) and identify that LiF formed in SEI (LiFSEI) has fruitful spectroscopy features that originated from the formation of limited LiF-LiH solid solutions: H-rich phase (LiH1-yFy) and F-rich phase (LiF1-xHx), which is further validated by 6Li isotope NMR, synchrotron X-ray diffraction and cryo-electron microscopy (cryo-EM). By characterizing SEI formed in various electrolytes, we confirm the dominance of LiH1-yFy in high-coulombic-efficiency electrolyte, which can be rationalized by the fact that LiF-LiH solid solution shows improved ionic conductivity over LiF. As a proof of concept, we demonstrate that LiH1-yFy-rich coating layer presents obvious advantages compared with LiF-rich coating layer in lithium-metal batteries. This revised understanding of the heterogeneous nature of SEI components would provide new insights for electrode-electrolyte interface design.

Chitosan, a versatile alkaline polysaccharide rich in amine and hydroxyl groups, has garnered significant research interest due to its abundance, low toxicity, biodegradability, and antibacterial properties. With rising concerns over energy scarcity and environmental pollution from fossil fuels, chitosan-based composites offer a promising solution for sustainable development. The unique coordination chemistry of chitosan enables it to form stable composites with various functional materials, enhancing its properties and broadening its applications, particularly in advancing a circular economy. This review provides a comprehensive overview of chitosan extraction and modification techniques, focusing on its applications in environmental remediation, energy conversion and storage, and biomedicine. We begin with an overview of common extraction and modification methods for chitosan, followed by an in-depth analysis of preparation techniques and operational parameters that influence the material properties and performance of chitosan-based composites in specific applications. This review presents the most thorough analysis to date, utilizing a novel classification framework to help readers systematically grasp the latest research developments. Additionally, we assess the economic and environmental impacts of chitosan-based composite applications, offering insights into their feasibility. Finally, we summarize the challenges and future directions for chitosan-based composites, providing valuable guidance for practitioners and decision-makers.

A small amount of Mg2+ doping can show a significant effect on the surface protection and structural stability of the nickel-rich layered oxide cathode, but the traditional doping process involves completely changing the initial raw material proportions with subsequent trial and error adjustments. Herein, a concept of Mg2+ release film is proposed, in which Mg2+ can easily permeate into various layered oxide cathodes during cycling. Meanwhile, to realize this concept, MgV2O4 with mobile Mg2+ in the structures and then fabricated a self-supporting MgV2O4 membrane are synthesized. As a protective layer for cathode, the MgV2O4 membrane release Mg2+ in situ during the electrochemical process, providing structural reinforcement to the cathode surface as a "pillar" within the lattice. Thanks to the MgV2O4 membrane, the cycle life of LiNio.8Co0.1Mn0.1O2(NCM811) coupled with the MgV2O4 interlayer at 1.0 C is increased by 1.9 times compared to bare NCM811. Furthermore, this novel Mg2+ releasing film demonstrates excellent versatility, enabling other nickel-based layered oxide to achieve a high-capacity retention of 86.4% after 800 cycles at 1.0 C. This approach provides scalable cathode protection and repair strategies for commercially viable batteries.