Hierarchical ZnO–Graphite Films Enabling Durable Antifouling and Corrosion Protection of Electrochemical Electrodes in Harsh Wastewater Environments

In microbial electrochemical coupled treatment technology, the performance of electrodes critically affects the overall efficiency of wastewater treatment systems. Electrochemical electrodes in harsh wastewater often fail due to coupled organic fouling and corrosion. Herein, hierarchical ZnO–graphite composite films are developed as durable active interfaces. Fabricated via scalable spraying, the films feature coral-like architectures composed of ZnO nanoparticles interconnected by a conductive graphite network. Characterization confirms uniform elemental integration and preserved ZnO crystallinity. The films exhibit strong hydrophilicity, facilitating a stable hydration layer for effective underwater oleophobicity. Crucially, electrochemical tests in aggressive simulated landfill leachate demonstrate significant corrosion suppression and fouling resistance. Simultaneously, the embedded graphite phase ensures stable electrical conductivity (<5% variation) over prolonged immersion. This work establishes a robust interfacial design strategy for durable electrochemical sensors in complex wastewater environments.