A Non‐van der Waals Superlattice Breakthrough: Engineered Atomic Layer Assemblies

Artificial superlattices assembled from two-dimensional (2D) atomic layers have emerged as a transformative platform for developing materials with superior properties. However, currently, the majority of artificial superlattice systems are van der Waals (vdW) in nature, limited by weak interlayer coupling, constraining their groundbreaking technological applications. In a recent Nature report, Zhao et al. introduce an innovative stiffness-mediated rolling-up strategy that transforms MAX-phase-derived MXenes into hydrogen-bonded, non-vdW superlattices of carbides and carbonitrides. By modulating the bending stiffness through controlled metal-vacancy formation, the authors achieve one-dimensional scrolls with robust interlayer electronic coupling and exceptionally high charge-carrier density. This approach transcends conventional exfoliation-based stacking, unveiling a new class of 2D superlattices stabilized beyond the vdW interaction, where non-vdW hydrogen-bond-mediated coupling enables strong interlayer coherence and significantly enhanced charge mobility. These non-vdW superlattices deliver remarkable electrical conductivity (∼30,000 S cm−1, almost 22 times higher than conventional counterparts) and exceptional electromagnetic interference (EMI) effectiveness (124 dB), setting a new benchmark for artificial superlattice systems of comparable thickness. The field of 2D materials has undergone a remarkable transformation over the past decade, with artificial superlattices emerging as a critical frontier in materials science. These intricate atomic layer assemblies offer unprecedented opportunities to engineer materials with properties that far surpass traditional bulk counterparts. Historically, superlattices have been predominantly constructed from vdW atomic layers derived from materials such as graphite, transition metal sulfides, and other layered compounds [1, 2]. These systems have demonstrated fascinating phenomena, particularly in moiré superlattices, including unconventional superconductivity [3, 4], ferromagnetism [5], and correlated insulating behavior. Yet despite their conceptual novelty and technological advancements, fundamental challenges have persistently limited the potential of existing superlattice approaches. The weak interfacial coupling inherent in vdW systems restricts charge transfer and electronic interactions, whereas their fabrication is always difficult and challenging to scale up, constraining performance and practical application potential. Bridging this coupling gap has therefore become a critical challenge. Researchers have long sought strategies to overcome these limitations, exploring various approaches to enhance interlayer interactions and create more sophisticated artificial material systems [6]; however, a generalizable route to 2D superlattices that are structurally robust and support strong interlayer electronic transport has yet to be realized. Zhao et al. now present a conceptually distinct route for constructing novel artificial superlattices [7]. By introducing a “stiffness-mediated rolling-up” strategy, the researchers have developed a series of non-vdW superlattice materials with robust hydrogen-bonded interlayer coupling, successfully addressing traditional limitations of vdW superlattices. The core innovation lies in a precise manipulation of atomic layer mechanics, achieved through metal-vacancy engineering in MAX phase (where M represents an early transition metal, A denotes an element from Groups 13–16, and X is C and/or N) slabs. The synthetic protocol involves a complex process of customizing the bending stiffness of atomic layers, triggering an ordered rolling-up mechanism through rapid delamination and flexural deformation [8, 9]. This assembly route not only circumvents the need for complex manual stacking or epitaxial alignment but also yields robust interlayer electronic coupling, transforming a purely physical assembly process into one that is chemically anchored. Impressively, the strategy supports a compositionally diverse library of superlattices, with 17 distinct nanoscrolls demonstrated across vanadium, titanium, niobium, and tantalum-based carbides and carbonitrides. Among these diverse compositions, the V2CTx system offers particularly insightful perspectives into the fundamental mechanisms and functional characteristics of these novel materials. By strategically selecting V2AlC (MAX phase) as a precursor and employing an innovative in situ etching procedure with variable valence vanadium states, Zhao et al. achieve a remarkable multilayer MXene delamination and rolling-up process within 0.3 s using tetrabutylphosphonium hydroxide (TBPH). The intricate transformation from V2AlC-phase-derived atomic layers to hydrogen-bonded scrolls unveils a sophisticated mechanism of material engineering, showcasing how precise atomic-scale manipulation can lead to emergent material properties. The detailed characterization (Figure 1A) reveals a theoretical roll-up model that illuminates the critical role of hydrogen bonding in forming these non-vdW superlattices. Transmission electron microscopy (TEM) images (Figure 1B) showcase uniformly distributed nanoscrolls with diameters ranging from 20 to 100 nm, demonstrating the precise control over material architecture. The high-resolution transmission electron microscopy (HRTEM) (Figure 1C) unveils a fascinating moiré periodic pattern with hexagonal unit cells, providing visual evidence of the sophisticated layer arrangement. Hierarchical evolution and functional characteristics of V2CTx non-vdW superlattices. (A) A roll-up model of a single atomic layer at a stable state (Ef ≤ 0), in which hydrogen bonding is presented between adjacent atomic layers. (B) TEM image of the superlattices. (C) The corresponding HRTEM image, exhibiting a Moiré periodic pattern with hexagonal unit cells (orange hexagon). The inset shows the corresponding moiré superlattice model. (D) Current–voltage curve of a single superlattice measured by the four-probe method. The inset shows a magnified SEM image of a single superlattice device. (E) Comparison of SSE/t of V2CTx superlattice films with the reported shielding materials. Reproduced with permission from Ref. [7]. Copyright 2025, Springer Nature. The electrical characteristics (Figure 1D) illustrate the current-voltage curve of a single V2CTx superlattice, confirming the high conductivity and linear charge transport behavior through four-probe measurements. The non-vdW superlattices demonstrate an unprecedented charge-carrier concentration of 1022 cm−3, enabling an exceptional electrical conductivity of approximately 30,000 S cm−1, which is a remarkable leap forward in material performance. The practical implications of this research extend far beyond fundamental materials science. When applied to EMI shielding, these superlattices achieve an unprecedented 124 dB shielding effectiveness, the highest reported for synthetic materials of similar thickness [10]. The specific shielding effectiveness (SSE/t) reaches around 200,000 dB cm2 g−1, about three times that of reported Ti-based MXenes (Figure 1E). This extraordinary result substantially outperforms existing synthetic materials, highlighting the transformative potential of the non-vdW superlattice approach. The unique structural characteristics arise from the strong hydrogen bonding and elimination of rotational disorder typical in vdW superlattices. This work represents more than just a scientific advancement: It offers a new paradigm for 2D superlattice material design. By demonstrating the ability to create controlled, robust interlayer coupling, the researchers have opened a new frontier in artificial material construction. The strategy promises transformative advances across multiple technological domains, from advanced electronics to energy storage and conversion systems. Future research directions are numerous and exciting. Scientists can explore expanded material combinations, delve deeper into understanding the intricate interfacial dynamics, and investigate broader application landscapes. The demonstrated rolling-up strategy provides a versatile blueprint for creating artificial material systems with unprecedented functionalities. The non-vdW superlattice approach exemplifies the power of strategic interface engineering. By challenging existing limitations and introducing a novel atomic layer assembly mechanism, this research illuminates a new path in materials science. It demonstrates how precise control of atomic interactions can unlock extraordinary material properties, offering a glimpse into a future where materials can be designed with unprecedented sophistication and performance. As the boundaries of materials science continue to expand, this work stands as a testament to human ingenuity and the endless possibilities of atomic-scale engineering. Qingmei Hu contributed to conceptualization, writing – original draft, funding acquisition. Xiang Miao contributed to manuscript structure, scientific interpretation, review and editing, funding acquisition. Jiadong Zhou contributed to project supervision, strategic insights, writing – review and editing, project administration, funding acquisition. This work was financially supported by the National Key R&D Program of China (Grant Nos. 2022YFA1203901 and 202221855043), the National Natural Science Foundation of China (Grant Nos. 62174013, 92265111, 12104050, 12404547, and 52502208), the National Science Foundation for Distinguished Young Scholars (Grant No. JQ23007), the Beijing Natural Science Foundation (Grant No. L233003), and the Funding Program of Beijing Institute of Technology (Grant No. 3180021502353). The authors acknowledged Analysis and Testing Center in Beijing Institute of Technology. The authors declare no conflicts of interest. The authors have nothing to report.