Bioinspired Rod‐In‐Hollow‐Tube Structure With Linear Contact MoO 3 @NiMoO 4 Interface Boosting Charge Transfer and Surface Reactivity for Enhanced Triethylamine Sensing

ABSTRACT Inspired by the efficient mass transport and interfacial exchange of natural vascular bundles, this study presents a bioinspired rod‐in‐hollow‐tube architecture, MoO 3 @NiMoO 4 ‐TH, engineered via precise kinetic control of the Kirkendall effect. This unique structure features a highly ordered, high‐curvature linear heterointerface between the MoO 3 core and NiMoO 4 shell, which significantly enhances charge transfer and reaction dynamics. The optimized heterostructure demonstrates exceptional triethylamine (TEA) sensing performance, achieving a remarkable response (R a /R g = 513.5 ± 3.8, n = 3 at 50 ppm TEA and 210°C) and ultrafast response/recovery times (7 s/51 s) with linear detection ranges from 0.5 to 200 ppm TEA and a low detection limit of 137 ppb. In situ spectroscopic analysis and finite element simulations reveal that the well‐defined heterointerface promotes directional electron migration, enriches reactant concentration via confinement effects, and facilitates efficient activation of oxygen species. Compared to randomly distributed heterostructures, the rod‐in‐hollow‐tube configuration exhibits high surface energy and accelerated charge separation, thereby optimizing adsorption and oxidation kinetics. Practical application in monitoring fish freshness further underscores the reliability of sensors. This work establishes a generalized strategy for designing biomimetic nanomaterials with tailored interfaces, advancing high‐performance sensors for real‐time environmental monitoring and food safety.