Academic Research Journal•2026•DOI: 10.26599/NR.2026.94908633
Covalent organic frameworks (COFs) with highly symmetric skeletons exhibit limited O2 adsorption and weak thermodynamic driving force for the two-electron oxygen reduction reaction (2e− ORR), constraining photocatalytic H2O2 production. Here, we modulate the local arrangement of fluorine atoms in COFs, creating para- and ortho-fluorinated variants (Fp-COFs and Fo-COFs) to induce an asymmetric electronic distribution. This asymmetry provides effective O2-adsorption sites and strengthens the driving force for 2e− ORR. Theoretical analysis reveals that asymmetric fluorination delocalizes lone-pair electrons of F atoms to adjacent carbons, producing a discretized electron distribution that enhances O2 adsorption at imine bonds. The increased electron density on these carbons facilitates electron transfer into the π* orbital of adsorbed O2, accelerating ·OOH* intermediate formation and lowering the Gibbs free energy barrier of the 2e− pathway. Consequently, Fo-COFs achieve a quantum yield of 8.8% for H2O2 photosynthesis in pure water. This work provides a new approach for tuning local electron distribution in COFs, offering guidance for rational design of efficient photocatalytic materials and broadening the application prospects of asymmetric electronic structures.
Academic Research Journal•2026•DOI: 10.26599/NR.2026.94908587
Aerogels are promising for thermal insulation due to their lightweight and low thermal conductivity, yet achieving high-temperature resistance (>1000 °C) alongside robust mechanical performance remains challenging. Here, we report a cactus-inspired spiral structure strategy via freezing-assisted direct ink writing (DIW). By controlling the rotation angle (θ) and printing spacing (x), we fabricate SiO2/ZrO2 aerogels with programmable macroscopic spiral architectures. The aerogel with θ = 40° and x = 1.3 mm exhibits excellent thermal insulation (30.2 mW·m−1·K−1) but limited compressive strength (159.3 kPa at 24.2% fracture strain). To enhance mechanical properties without compromising insulation, we propose an arctangent-topological DIW strategy using αn = arctan(1/n) to create four-fold rotational symmetry. At αn = 26.6° (n = 2), the aerogel achieves a thermal conductivity of 33.9 mW·m−1·K−1 and a compressive strength of 341.7 kPa at 24.6% fracture strain, representing a significant improvement. Finite element simulations (COMSOL Multiphysics) corroborate experimental results. Demonstrations on electronic chips and flame nozzles confirm effective thermal protection. This work provides a viable route to aerogels with integrated high-temperature stability and mechanical robustness.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2026•DOI: 10.1016/j.ijmst.2026.02.003
Efficient flocculation and sedimentation of ultrafine hematite remain a key challenge in mineral processing. This study elucidates the pH-dependent flocculation behaviour of hematite with anionic polyacrylamide (APAM) using a multi-scale correlation framework integrating interfacial analysis, structural characterization, and sedimentation evaluation. Increasing pH induces progressive surface deprotonation, yielding a more negative hematite surface and enhanced APAM adsorption from 0.106 to 0.186 mg/m2. FTIR, XPS, and molecular dynamics simulations consistently reveal strengthened Fe–OOC coordination, intensified hydrogen bonding, and more stabilised polymer conformations under alkaline conditions. Microscopy, SEM, and FBRM show that alkaline conditions facilitate the formation of larger and denser flocs, with size increasing from 56 to 982 μm and fractal dimension from 1.44 to 1.87. These structural changes markedly improve sedimentation performance, reducing turbidity from 436.8 to 76.7 NTU and increasing settled solids from 35.94 to 52.43 percent. The proposed multi-scale correlation model quantitatively links interfacial chemistry, floc structural evolution, and settling behaviour, providing a unified mechanistic basis for pH-regulated hematite flocculation. This framework not only advances understanding of polymer–mineral interactions but also offers practical guidance for optimising solid–liquid separation and tailings-water recycling in fine mineral beneficiation.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01771-8
Daytime radiative cooling is an eco-friendly and passive cooling technology that operates without external energy input. Materials designed for this purpose are engineered to possess high reflectivity in the solar spectrum and high emissivity within the atmospheric transmission window. Unlike broadband-emissive daytime radiative cooling materials, spectrally selective daytime radiative cooling (SSDRC) materials exhibit predominant mid-infrared emission in the atmospheric transmission window. This selective mid-infrared emission suppresses thermal radiation absorption beyond the atmospheric transmission window range, thereby improving the net cooling power of daytime radiative cooling. This review elucidates the fundamental characteristics of SSDRC materials, including their molecular structures, micro- and nanostructures, optical properties, and thermodynamic principles. It also provides a comprehensive overview of the design and fabrication of SSDRC materials in three typical forms, i.e., fibrous materials, membranes, and particle coatings, highlighting their respective cooling mechanisms and performance. Furthermore, the practical applications of SSDRC in personal thermal management, outdoor building cooling, and energy harvesting are summarized. Finally, the challenges and prospects are discussed to guide researchers in advancing SSDRC materials.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01640-w
The large-scale use of ample marine energy will be one of the most important ways for human to achieve sustainable development through carbon neutral development plans. As a burgeoning technological method for electromechanical conversion, triboelectric nanogenerator (TENG) has significant advantages in marine energy for its low weight, cost-effectiveness, and high efficiency in low-frequency range. It can realize the efficient and economical harvesting of low-frequency blue energy by constructing the floating marine energy harvesting TENG. This paper firstly introduces the power transfer process and structural composition of TENG for marine energy harvesting in detail. In addition, the latest research works of TENG on marine energy harvesting in basic research and structural design are systematically reviewed by category. Finally, the advanced research progress in the power take-off types and engineering study of TENG with the marine energy are comprehensively generalized. Importantly, the challenges and problems faced by TENG in marine energy and in situ electrochemical application are summarized and the corresponding prospects and suggestions are proposed for the subsequent development direction and prospects to look forward to promoting the commercialization process of this field.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)67026-9
A novel SnAgCu composite solder with multi-phase and multi-scale hybrid reinforcement was developed. Initially, surface modification of nano-sized ZrO2 and micro-sized tetra-needle-like ZnO whisker (T-ZnOw) was performed using pyrolysis method. Subsequently, the modified ZrO2 and T-ZnOw were incorporated into Sn1.0Ag0.5Cu composite solders using an ultrasonic-assisted casting method. The microstructure evolution, interface between solder matrix and reinforcements, and mechanical properties were systematically investigated. The results indicated that the composite solder exhibited a high proportion of eutectic structures with minimal coarse intermetallic compounds. Furthermore, at the interface between the reinforcements and Sn1.0Ag0.5Cu, no gaps, micropores, or new phases were observed, while atomic inter-diffusion was detected. When the Zn/Zr molar ratio was set to be 2꞉3, the composite solder achieved an ultimate tensile strength of 35.9 MPa and an elongation of 31.4%, representing improvements of 30.5% and 47.4%, respectively, compared to plain Sn1.0Ag0.5Cu solder.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01353-0
The huge impact kinetic energy cannot be quickly dissipated by the energy-absorbing structure and transferred to the other vehicle through the car body structure, which will cause structural damage and threaten the lives of the occupants. Therefore, it is necessary to understand the laws of energy conversion, dissipation and transfer during train collisions. This study proposes a multi-layer progressive analysis method of energy flow during train collisions, considering the characteristics of the train. In this method, the train collision system is divided into conversion, dissipation, and transfer layers from the perspective of the train, collision interface, and car body structure to analyze the energy conversion, dissipation and transfer characteristics. Taking the collision process of a rail train as an example, a train collision energy transfer path analysis model was established based on power flow theory. The results show that when the maximum mean acceleration of the vehicle meets the standard requirements, the jerk may exceed the allowable limit of the human body, and there is a risk of injury to the occupants of a secondary collision. The decay rate of the collision energy along the direction of train operation reaches 79%. As the collision progresses, the collision energy gradually converges in the structure with holes, and the structure deforms when the gathered energy is greater than the maximum energy the structure can withstand. The proposed method helps to understand the train collision energy flow law and provides theoretical support for the train crashworthiness design in the future.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01316-5
This study decouples the material microstructure into matrix and void phases. The undamaged constitutive is derived from the matrix phase, while the void phase contributes to damage evolution. A constitutive model is established by coupling the two. According to the void-phase evolution during damage, a damage sequence interaction model is proposed. Tests on new vehicles and vehicles in service materials yield stress-strain curves of materials without and with fatigue damage and measure the apparent elastic modulus. The damage sequence interaction model accurately predicts the residual mechanical properties of undamaged materials. A trolley collision test validates the constitutive model. Collision simulations at 25, 36, and 48 km/h reveal that compared with undamaged models, the maximum vertical lift heights of moving vehicles with fatigue damage are 4.54%, 3.74%, and 9.17% lower, respectively, and the maximum longitudinal compressions of stationary vehicles are 4.76%, 14.53%, and 33.15% higher respectively. This research emphasizes the importance of considering fatigue damage in vehicle design and maintenance. The damage sequence interaction model has high engineering application value, applicable to vehicle safety checks and design, and provides a reference for improving relevant standards.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3269-5
Low-concentration coal mine methane (LC-CMM), which is predominantly composed of methane, serves as a clean and low-carbon energy resource with significant potential for utilization. Utilizing LC-CMM as fuel for solid oxide fuel cells (SOFCs) represents an efficient and promising strategy for its effective utilization. However, direct application in Ni-based anodes induces carbon deposition, which severely degrades cell performance. Herein, a medium-entropy oxide Sr2FeNi0.1Cr0.3Mn0.3Mo0.3O6−δ (SFNCMM) was developed as an anode internal reforming catalyst. Following reduction treatment, FeNi3 nano-alloy particles precipitate on the surface of the material, thereby significantly enhancing its catalytic activity for LC-CMM reforming process. The catalyst achieved a methane conversion rate of 53.3%, demonstrating excellent catalytic performance. Electrochemical evaluations revealed that SFNCMM-Gd0.1Ce0.9O2−δ (GDC) with a weight ratio of 7:3 exhibited superior electrochemical performance when employed as the anodic catalytic layer. With H2 and LC-CMM as fuels, the single cell achieved maximum power densities of 1467.32 and 1116.97 mW·cm−2 at 800°C, respectively, with corresponding polarization impedances of 0.17 and 1.35 Ω·cm2. Furthermore, the single cell maintained stable operation for over 100 h under LC-CMM fueling without significant carbon deposition, confirming its robust resistance to carbon formation. These results underscore the potential of medium-entropy oxides as highly effective catalytic layers for mitigating carbon deposition in SOFCs.