Key Takeaways & Executive Findings
- •• • h-BN/Mg composites exhibit interface bonding features that directly influence mechanical properties; dry sliding wear behavior of Mg/BN nanocomposites shows measurable improvements in wear resistance, critical for lightweight automotive and aerospace components where friction and mass reduction are paramount. • • Field-sintered boron nitride nanotube-magnesium alloy composites demonstrate direct observation of strengthening behavior, with interface engineering yielding enhanced load transfer, essential for structural applications requiring high specific strength. • • Cu/h-BN nanocomposites synthesized via powder metallurgy achieve physico-mechanical and tribological property enhancements, with h-BN acting as a solid lubricant; this is industrially relevant for electrical contacts and bearings where friction and wear reduce service life. • • Boron nitride nanosheet/copper nanocomposites via molecular-level mixing show enhanced mechanical properties, and TiN transition interface in BNNS/Cu composites cooperatively enhances mechanical and tribological properties, addressing the bottleneck of weak interfacial bonding in metal matrix composites.
China Clean Energy & Battery Radar
Get verified English translations, SEM micrographs & open-access PDF alerts from China's leading state key laboratories delivered to your inbox every Monday at 08:00 EST.
Abstract
Hexagonal boron nitride (h-BN) possesses a unique combination of high thermal conductivity, superior hardness, outstanding chemical stability, and a wide bandgap (~5.5–6 eV), rendering it indispensable for high-temperature lubrication, thermal management, electronic devices, and superhard tools. The performance of h-BN/metal systems is fundamentally governed by interfacial characteristics, including atomic structure, chemical bonding, electronic band alignment, and defect states. This review systematically analyzes interface engineering in h-BN/metal systems via two primary routes: in situ growth and ex situ compositing. During in situ growth of h-BN thin films on metal substrates (e.g., Cu, Ni), the metal substrate and growth conditions exert multifaceted influences on film quality through interfacial coupling, directly impacting contact resistance, operational stability, and noise characteristics in devices such as field-effect transistors and photodetectors. For ex situ preparation of h-BN/metal composites, interface construction is synergistically determined by h-BN dimension, matrix properties, and fabrication process. Empirical studies on Mg/BN and Cu/BN composites demonstrate that interface engineering, including surface modification and transition layers (e.g., TiN), significantly enhances mechanical and tribological properties. This review elucidates fundamental principles and unique mechanisms of h-BN/metal interface control, providing strategic insights for designing advanced h-BN-based functional devices and composites.
1. Introduction
Commercial deployment of h-BN/metal systems has been impeded by inadequate interfacial control, leading to premature failure in electronic devices and composites. In h-BN-based field-effect transistors and photodetectors, metal contacts often exhibit high contact resistance and instability due to poor h-BN/metal interface quality, limiting on-off ratios and increasing noise. Similarly, in metal matrix composites, the chemically inert nature of h-BN results in weak bonding with metal matrices, causing inefficient load transfer and degraded mechanical performance. Existing approaches, such as simple mechanical mixing or unoptimized growth, fail to address the atomic-level structural and chemical discontinuities that govern charge transfer and mechanical integrity.
This review confronts these bottlenecks by systematically analyzing interface engineering in h-BN/metal systems through two distinct pathways: in situ growth and ex situ compositing. For in situ growth, the metal substrate and growth conditions are shown to dictate h-BN crystallinity, planarity, and topological structure via interfacial coupling. For ex situ composites, interface construction is synergistically determined by h-BN dimension, matrix properties, and fabrication process. By elucidating fundamental principles and unique mechanisms, this work provides strategic insights for designing advanced h-BN-based devices and composites with optimized interfacial properties.
Loading authentic research manuscript (Pages 1–5)...
Jian Yang, Shaoqiang Zhu, Dongdong Zhao, Xudong Rong, Xiang Zhang, Naiqin Zhao, Chunnian He (2025). Interface engineering in hexagonal boron nitride/metal systems: from in situ growth to metal matrix composites. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-025-3592-5
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What are the primary failure mechanisms at h-BN/metal interfaces under mechanical or thermal stress?
Failure mechanisms include weak van der Waals bonding leading to interfacial debonding, and chemical incompatibility causing void formation. In Mg/BN nanocomposites, dry sliding wear tests reveal that inadequate interfacial bonding results in pull-out of BN reinforcements, accelerating wear rates. For Cu/h-BN composites, without interface engineering, h-BN acts as a stress concentrator, reducing tensile strength. Surface modification and transition layers (e.g., TiN) mitigate these by forming chemical bridges that enhance load transfer and thermal stability.
How does the dimension of h-BN (nanotube vs. nanosheet) affect composite performance?
BN nanotubes (BNNTs) provide high aspect ratio and continuous reinforcement, leading to significant strengthening in Mg alloys, as observed in field-sintered BNNT-Mg composites. BN nanosheets (BNNSs) offer large interfacial area for load transfer but may agglomerate; molecular-level mixing in Cu/BNNS composites achieves uniform dispersion and enhanced mechanical properties. Hybrid BNNT/BNNS reinforcements in AZ91 Mg composites exploit both dimensional advantages, improving microstructure and mechanical properties synergistically.
What are the scalability and cost bottlenecks for industrial production of h-BN/metal composites?
Scalability is hindered by the high cost of high-quality h-BN (especially nanotubes and nanosheets) and the complexity of achieving uniform dispersion. Powder metallurgy routes for Cu/h-BN nanocomposites are scalable but require careful control of sintering parameters to avoid interfacial reactions. In situ growth on metal substrates is limited by substrate size and batch uniformity. Cost parity with conventional composites requires reducing h-BN synthesis costs and optimizing fabrication processes to minimize waste and energy consumption.
How does interface engineering impact tribological properties in h-BN/metal composites?
Interface engineering directly influences tribological performance by controlling the formation of lubricious tribofilms and load-bearing capacity. In Cu/h-BN composites paired with C/C-SiC, h-BN modifies the friction coefficient and wear rate by forming a transfer film. TiN transition interfaces in BNNS/Cu composites enhance both mechanical and tribological properties by improving interfacial bonding and preventing h-BN pull-out. For Mg/BN nanocomposites, dry sliding wear tests show reduced wear volume with optimized interfaces.
What are the key challenges in characterizing h-BN/metal interfaces at the atomic scale?
Challenges include the buried nature of interfaces, electron beam sensitivity of h-BN, and the need for correlative techniques. Advanced methods such as high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) can reveal atomic structure and bonding, but sample preparation is critical. In situ studies during growth or deformation are essential to understand dynamic interfacial processes, yet remain technically demanding.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.