Carbon Dot Composite Mixed Ionic‐Electronic Device Based on Oxygen‐Proton Coupling Catalytic Mechanism

ABSTRACT Here, we report a memristive device based on a carbon dot‐polyaniline (CDot‐PANI) composite, working with an oxygen/proton coupled catalytic mechanism. Under external proton and oxygen stimulation, CDots catalyze a proton‐assisted oxygen reduction reaction (ORR), which accelerates electron/proton transfer and dynamically modulates the ES/PNB redox transition of PANI. This coupled ORR‐oxidation pathway enables fully reversible, catalyst‐driven switching between high‐ and low‐conductance states. The CDot‐PANI composite exhibits strengthened electronic transport, high structural stability, and pronounced hysteretic switching behavior. Importantly, the coupled oxygen/proton stimuli trigger a spectrum of synaptic functions, including tunable short‐ and long‐term plasticity (STP‐LTP) and brain‐like learning‐forgetting dynamics, demonstrating that neuromorphic behaviors originate from electrochemically mediated catalytic processes rather than conventional filamentary or vacancy‐based mechanisms. A fully coupled Poisson‐Nernst‐Planck (PNP) and Butler‐Volmer (B‐V) kinetic model further reveals the formation of ORR‐induced proton concentration gradients, nonuniform potential distributions, and deep ion penetration arising from cascade oxygen‐proton redox reactions. These simulations suggest that the memristive switching stems from catalytic reaction‐driven ionic redistribution within the composite. This work establishes a mechanistic basis for metal‐free mixed ionic‐electronic devices and a design strategy for neuromorphic electronics.