Beyond van der Waals: Modular Identification of 2D Materials in Strongly Bonded Layered Crystals

Abstract

Abstract Top‐down exfoliation of layered solids has revolutionized materials innovation by enabling unprecedented access to atomically thin architectures. To expand the frontier of two‐dimensional (2D) materials, it is imperative to systematically identify non‐van der Waals (non‐vdW) layered systems with strong interlayer bonding. While conventional atomic distance‐based algorithms effectively identify vdW materials, they are considerably limited when applied to chemically bonded non‐vdW systems due to their inherent bonding complexity. Here, we introduce a structural modularity paradigm that resolves dimensional identification challenges by removing specific elements from strongly bonded crystals to construct artificial substructures from residual atoms. Coupled with the appropriate layer‐recognition algorithms for vdW lattices, this approach reveals 8,889 hidden 2D modules across 30,147 ternary compounds, of which 80.6% are undetectable by traditional layer‐detection approaches. These findings show that non‐vdW layered solids significantly outnumber vdW counterparts (1,383), highlighting a vast chemical space for 2D materials exploration. High‐throughput thermodynamic screening of 15,312 ternary oxides identifies 1,083 chemically stable 2D modules exfoliable via a proton exchange‐assisted method. Validation against 15 experimentally reported 2D oxide nanosheets, along with the first synthesis of ultrathin H x RuO 3 nanosheets from non‐vdW Na 2 RuO 3 crystal, confirms the reliability and predictive strength of this method for both known and previously unexplored systems.