SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4394-x
Spiral graphene, characterized by Bernal-stacked layers and unique electronic properties, holds promise for advanced quantum and optoelectronic devices. However, its controlled synthesis remains challenging. Here, we report the self-assembly growth of single-crystal spiral graphene on a liquid heterogeneous substrate via chemical vapor deposition (CVD). A 50-μm-thick Cu foil was placed on a Ni support and heated to 1083 °C, the melting point of pure Cu, ensuring a fully molten Cu layer on solid Ni. Growth proceeded for 30 minutes under optimized conditions. The resulting spiral graphene exhibits a uniform Bernal stacking configuration, as confirmed by transmission electron microscopy and selected-area electron diffraction. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling and isotope-labeling experiments reveal that carbon incorporation occurs predominantly at the spiral step edges, following a self-assembly mechanism driven by the liquid substrate's dynamic surface. Control experiments on solid Cu-Ni alloys yield no spiral morphology, underscoring the critical role of the liquid phase. The liquid heterogeneous substrate facilitates rapid carbon diffusion and step-edge attachment, enabling the growth of high-quality single-crystal spirals with controlled layer number. This work provides a scalable route to synthesize spiral graphene with tailored stacking, advancing its application in twistronics and high-performance electronics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3633-5
High-temperature interfacial diffusion in Half-Heusler (HH) thermoelectric devices poses significant challenges for practical applications, particularly the diffusion of Ag from conventional solders, which degrades material performance and device stability. This study reveals anomalous Ag diffusion through a Cr powder barrier layer into Ti0.5Zr0.5NiSn0.98Sb0.02, driven by Sn phase penetration. In contrast, employing a Cr foil barrier layer pre-densified the material, effectively preventing Sn phase penetration and eliminating Ag diffusion pathways, thereby preserving junction integrity. After aging at 973 K for 30 days, the Cr foil junction maintained a clean interface with a low contact resistivity of 0.27 μΩ cm2. Benefiting from this interfacial design, a Hf-free HH module achieved a high conversion efficiency of 10.4% at a hot-side temperature of 976 K, alongside long-term stability. This work addresses critical bottlenecks in developing high-performance, low-cost HH modules, facilitating their commercial application in waste heat recovery.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509067
Marine litter poses a significant threat to coastal ecosystems globally, necessitating a comprehensive understanding of its multi-compartment distribution and driving mechanisms for effective management. This study investigated the occurrence, composition, and sources of beach, sea surface, and seafloor litter in the northeastern Daya Bay, a semi-enclosed bay, during August–October 2024. Sampling included 11 beach transects, 6 surface transects, and 25 seafloor transects. Results showed that the mean density of large and very large beach litter was 4.41×10^5 items·km−2, while medium beach litter reached 5.39×10^6 items·km−2. Surface litter densities were 5.82×10^2 and 9.90×10^3 items·km−2 for large/very large and medium fractions, respectively. Seafloor litter averaged 5.20×10^3 items·km−2. Plastics dominated all compartments, accounting for 74.0% (beach), 96.0% (surface), and 78.8% (seafloor) of total litter. Source apportionment using NOWPAP methodology indicated that beach and surface litter primarily originated from coastal recreational activities, whereas seafloor litter was mainly derived from shipping and fishing. Beach quality assessment revealed that 63.6% of beaches were moderately clean or better (grade II–IV), and 90.9% were moderately safe or better (grade I–III). Hotspots included tourism beaches, tidal gyre areas, coral reef zones, and fishing grounds. The study underscores the need for targeted management, including improved waste collection on tourist beaches, dynamic cleaning protocols, and port reception facilities for fishing waste.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025030501
Coastal areas serve as critical ecological interfaces for the migration of terrestrial microplastics (MPs) into the ocean, and characterizing their pollution is essential for integrated coastal management. This study investigated the occurrence, sources, and ecological risks of MPs in surface waters of nearshore areas and river estuaries around Hainan Island, a typical tropical tourist island. MPs abundance ranged from 316.67 to 1300 n·m−3 in seawater and from 400 to 5416.67 n·m−3 in river water. In seawater, the dominant polymer was polyethylene terephthalate, with fibers being the predominant shape, size class 500–1000 μm, and white/transparent color. In river water, polypropylene-ethylene copolymer dominated, also as fibers, but with size class 100–500 μm and white/transparent color. Seawater MP abundance showed a significant positive correlation with tourist numbers, and distribution across functional areas followed: tourism areas > natural areas > aquaculture areas > residential areas. Multiple correspondence analysis identified household plastic waste, laundry wastewater, aquaculture, and fishery products as primary sources of seawater MPs. Principal component analysis indicated homologous characteristics between seawater and river MPs, suggesting rivers are a major pathway for terrestrial MP transport to coastal zones. Ecological risk assessment revealed low pollution loads, with potential ecological risks moderate for seawater and medium-low for river water. Notably, 15% of seawater sampling sites exhibited polymer risk level Ⅳ, primarily driven by polyacrylonitrile's high biological toxicity. These findings provide a scientific basis for developing MP pollution control strategies in Hainan Island.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4067-4
Confined growth of metal halide perovskite quantum dots (QDs) in porous matrices yields improved stability and sensitivity for their implementation in luminescent chemical sensing applications. Here, we realized the synthesis of highly stable (water, photo, and thermal) and luminescent CsPbX3 QDs within nanoporous glass (NG). This is achieved by a nano-confined aqueous synthesis of CsPbBr3 QDs in Pb-anchored NG. Benefiting from strong Pb–O–Si chemical bonding between the perovskite QDs and the NG matrix, the stability of the encapsulated perovskite QDs is significantly enhanced. The emission of the perovskite NG can be tuned from 440 to 760 nm. By integrating green- and red-emitting perovskite NG onto a blue LED chip, stable WLEDs were successfully fabricated. This facile approach enables the integration of ultra-stable perovskite QDs within transparent porous monoliths toward diverse luminescent chemical sensing applications.