SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3592-5
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.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3397-0
Carbon-supported single-atom catalysts (C-SACs) have been demonstrated as a strategy to promote the reversible conversion reaction of metal sulfide anodes in sodium-ion batteries (SIBs). However, the design principle of promising C-SACs remains lacking for obtaining highly reversible metal sulfide anodes. We designed a phosphorus-doped carbon-supported single-atom Mn catalyst (PC-SAMn) with an asymmetrical dual active center. The sulfiphilic Mn and sodiophilic P active centers adsorb discharged Na2S through Mn–S d-p and P–Na s-p orbital hybridizations. The asymmetrical dual active center induced the asymmetrical adsorption configuration of Na2S, which efficiently weakened Na–S bond strength and facilitated the decomposition of Na2S during charging. As a result, the designed catalyst enables typical MoS2 with a record-high compositional reversible degree of 89.61% and a low capacity decay ratio of only 0.18% per 100 cycles during 2000 cycles. The research establishes the “orbital hybridization–molecular structure–catalytic activity” relationship for guiding the design of highly reversible conversion-type materials.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3561-3
Nanoscale segregation of alien solute atoms at grain boundaries (GBs) can enhance the stability and mechanical properties of the GB. Systematic molecular dynamics simulations were conducted to clarify the strengthening effect of Cu segregation on Al Σ9 (221)[11̄0] GB. The predicted negative segregation energy indicates a strong driving force for Cu segregation at Al GBs, which is expected to improve GB stability and strength. Detailed structural analysis during uniaxial tensile testing reveals that Cu segregation reduces the free volume of GB atoms and restricts GB atomic displacement, thereby retarding dislocation nucleation and increasing the tensile strength of the GB. The suppressed atomic migrations by Cu doping also give rise to exceptional stability of E structures at the GB, which retain their kite shape against structural transition during straining. With Cu segregation, the pattern of dislocation nucleation from the GB shifts from a shuffling-assisted regime to a collective-migration regime, the latter necessitating higher critical stress. Furthermore, Cu doping elevates the GB shear strength by blocking shear-coupled GB migration under shear deformation. The enhanced GB resistance against shear straining is attributed to the stabilized E structures with Cu segregation featuring reduced atomic free volume. This study provides atomic-scale insights into the stabilizing and strengthening effect of Cu segregation on Al GBs.