Bypassing Lattice Registry: A Nonepitaxial Paradigm for Constructing Hierarchical Heteroarchitectures
Abstract
Epitaxial growth is a cornerstone of crystalline material design, yet its rigid dependence on the lattice registry fundamentally restricts the structural and compositional diversity of accessible nanoarchitectures. Here, we report a generalizable nonepitaxial growth paradigm that bypasses these atomic-scale constraints to construct complex 3D hierarchical heteroarchitectures. Using real-time liquid-phase transmission electron microscopy (LPTEM) and cryogenic-EM, we directly visualize a nonclassical crystallization sequence on AuAg alloy nanowires. The process is initiated with the rapid formation and long-range directional attachment of amorphous PdCl62– agglomerations, governed by noncontact interaction forces rather than traditional lattice matching. This is followed by condensation-driven volume shrinkage and a discrete amorphous to crystalline phase transition. Molecular dynamics simulations corroborate that these dynamics are driven by agglomeration-surface interactions, decoupling crystal growth from substrate registry. Atomic-resolution 3D electron tomography reveals a core–shell framework characterized by a dense network of grain boundaries and internal porosity (0.9%). These structural features impart enhanced oxygen reduction reaction (ORR) activity, achieving a 3-fold higher mass activity than commercial Pt/C benchmarks and a high tolerance to methanol and CO poisoning. By establishing a synthesis platform that decouples crystal growth from lattice registry, this work offers a versatile route for the precise engineering of hierarchical materials and multifunctional heteroarchitectures.