ABSTRACT Arranging functional units into a specific organization is a practical structural strategy for achieving fabulous performance, known as the functional unit and organization (FUO) paradigm. This paradigm offers a concise shortcut to establishing structure–performance relationships. Inspired by it, here we establish an efficient quantitative model to identify the mechanical performance of different organized nanotwin (NT) units in metals, following three critical steps. First, given the significant nonlinear elastic effect in ductile metals, we develop a bond strain‐based modulus model, which notably improves the precision of preyield response compared with the standard Cauchy–Born rule. Second, to address the inaccuracy of the traditional Schmid law in describing the critical resolved shear stress (CRSS), we systematically investigate the non‐Schmid factors, including normal stress, Escaig stress, and hydrostatic pressure, leading to a more universal yield condition. Third, the yield strengths are analytically solved without any iteration or relaxation, enabling fast structure–performance quantification. Beyond predicting elastic modulus and yield strength, this model also helps identify dominant plastic mechanisms (boundary vs. dislocation, grain growth vs. refinement), especially for textured structures exhibiting spacing‒orientation coupling. Our FUO‐based model provides a pathway to readily obtain mechanical performances of different organized nanotwins by bridging atomic simulations and continuum mechanics.
ABSTRACT Developing bifunctional electrocatalysts that combine high activity with durable operation is crucial for advancing alkaline water electrolysis toward practical hydrogen production. However, simultaneously promoting hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at high current densities remains challenging due to limited interfacial charge transfer and mass transport. Herein, we demonstrate that integrating a hollow conductive phosphide scaffold with a catalytically active nickel–iron (NiFe)‐layered double hydroxide (LDH) layer effectively regulates electron redistribution and reaction transport in bifunctional electrocatalysts. Accordingly, a hollow Co 2 P@NiFe LDH heterostructure was constructed on Ni foam (NF) via phytic‐acid‐assisted phosphidization followed by electrochemical deposition. The zeolitic imidazolate framework (ZIF)‐derived triangular hollow Co 2 P framework provides conductive pathways and an open architecture that facilitates electrolyte penetration and mass transport while forming a strongly coupled heterointerface with NiFe LDH. X‐ray photoelectron and absorption spectroscopy revealed partial Co–O(H) coordination and interfacial charge redistribution without loss of phosphide character, indicating effective electronic‐structure modulation. As a result, the H‐Co 2 P@NiFe LDH/NF electrode required overpotentials of only 165 mV for HER and 300 mV for OER to achieve 100 mA cm −2 in 1.0 M KOH. The assembled symmetric electrolyzer required only 1.79 V to deliver 100 mA cm −2 and maintained durable performance for over 50 h, demonstrating the effectiveness of hollow phosphide/LDH heterointerface engineering for efficient water splitting.
