Chirality‐Induced Spin Selectivity of Chiral 2D Perovskite Enabling Efficient Spin‐Dependent Oxygen Evolution Reaction

Abstract The sluggish and complex multi‐step oxygen evolution reaction remains an obstacle to bias‐free photoelectrochemical water‐splitting systems. Several theoretical studies have suggested that spin‐aligned intermediate radicals can significantly enhance the kinetic rates for oxygen generation. Herein, it is reported that the chirality‐induced spin selectivity phenomena can become an impressive approach by adopting chiral 2D organic–inorganic hybrid perovskites as a spin‐filtering layer on the photoanode. This chiral 2D perovskite‐based water‐splitting device achieves enhanced oxygen evolution performance with a reduced overpotential of 0.14 V, high fill factor, and 230% increased photocurrent compared to a device without a spin‐filtering layer. Moreover, combined with a superhydrophobic patterning strategy, this device realizes excellent operational stability by sustaining ≈90% of the initial photocurrent, even after 10 h.