Mortise-and-tenon joints enable isomorphic nanocluster superstructures: Ethyl groups as locking pins for benchmark photocatalytic H ₂ O ₂ production

Precise control over the isomorphic self-assembly of nanocluster superstructures via weak interactions remains a fundamental challenge in materials science, primarily due to the lack of directional guidance. Inspired by the ancient mortise-and-tenon joint, we herein report a series of crystalline nanocluster superstructures (MTC-1 and MTC-2) that are exclusively assembled by such molecular joints, representing the first paradigm of its kind. Despite alterations in functional groups (methyl vs. ethyl), the supramolecular packing motif remains invariant, underscoring the robustness of this directed assembly strategy. Notably, the ethyl groups in MTC-2 serve as "locking pins", resulting in MTC-2 a fascinating Luban lock-like construction. This ingenious design endows MTC-2 with enhanced photogenerated charge migration and superior O2 adsorption capability, achieving a record-high photocatalytic H2O2 production rate (19978 μmol·g-1·h-1) among all isolated crystalline cluster-based materials, an order-of-magnitude enhancement over existing benchmarks. This work not only presents a record-breaking photocatalyst but also establishes a general assembly strategy, the mortise-and-tenon joint, which is expected to guide the rational design of functional superstructures across diverse nanocluster systems.