Bioinspired Ion‐Gated Microscale Fe ⁰ for Selective Reductions with Targetable Proton and Electron Transfer

ABSTRACT The longstanding trade‐off between reactivity and electron utilization efficiency in zero‐valent iron (ZVI) presents a formidable barrier to their application in advanced wastewater treatment. Herein, inspired by the biological gating effect, we introduce an ion‐selective interaction‐gated proton‐coupled electron transfer (ISG‐PCET) strategy via surface phosphorylation engineering, which reconciles the conventional antagonism among reactivity, selectivity, and stability. The phosphorylated microscale ZVI (mZVI) forms distinct interactions: phosphate groups engage in hydrogen bonding with water molecules and ion–dipole interactions with pollutant molecules. Hydrogen bonding networks facilitate efficient proton transfer, while terminal oxygen atoms of the phosphate groups form ion–dipole interactions with the electron‐deficient carbon centers of trichloroethylene, activating the carbon–chlorine bond and orchestrating site‐specific nucleophilic electron attack and precise proton delivery. Biochar modification was employed to activate microelectrolysis to promote electron release. This sophisticated interfacial chemistry confers exceptional hydrodechlorination performance, as reflected by up to 28.4‐fold and 87.5‐fold improvements in removal efficiency and reaction kinetics, respectively, alongside a notable electron utilization efficiency of 79%, effectively suppressing parasitic hydrogen evolution. This work demonstrates the capability to precisely regulate interfacial proton‐electron synergy via the phosphorylation‐gated PCET, thereby establishing a promising platform for rationally designing efficient interfaces for selective reductive remediation.