Fluorinated Organic Cations Derived Chiral 2D Perovskite Enabling Enhanced Spin‐Dependent Oxygen Evolution Reaction

Abstract Chirality‐induced spin selectivity observed in chiral 2D organic–inorganic hybrid perovskite holds promise to achieve spin‐dependent electrochemistry. However, conventional chiral 2D perovskites suffer from low conductivity and hygroscopicity, limiting electrochemical performance and operational stability. Here, a cutting‐edge material design is introduced to develop a stable and efficient chiral perovskite‐based spin polarizer by employing fluorinated chiral cation. The fluorination approach effectively promotes the charge carrier transport along the out‐of‐plane direction by mitigating the dielectric confinement effect within the multi‐quantum well‐structured 2D perovskite. Integrating the fluorinated cation incorporated spin polarizer with BiVO₄ photoanode considerably boosts the photocurrent density while reducing overpotential through a spin‐dependent oxygen evolution reaction. Furthermore, the hydrophobic nature of fluorine in spin polarizer endows operational stability to the photoanode, extending the durability by 280% as compared to the device with non‐fluorinated spin polarizer.