Spin-Polarization Tailored Oxygen Evolution of Chiral Gold Nanocrystals Probed by Single-Particle Electrochemistry

The chiral-induced spin selectivity (CISS) effect presents a promising avenue for enhancing electrocatalytic processes through spin-polarized electron transfers. However, a comprehensive understanding of how nanoscale chirality influences catalytic activity has remained elusive. In this study, we employ scanning electrochemical cell microscopy (SECCM) to directly investigate the oxygen evolution reaction (OER) at individual chiral Au nanocrystals featuring precisely tunable helicoidal morphologies. Such a single-chiral-particle measurement allows the decoupling of the CISS effect from other influencing factors on the intrinsic OER activity. Our finding reveals that chiral D- and L-Au nanocrystals exhibit a 70% increase in OER activity compared to their achiral counterparts. Furthermore, the increasing OER activities of chiral nanocrystals with different helicities were statistically significant ( p < 0.001, ANOVA), leading to a positive correlation between spin polarization and chiral-enhanced activity. This single-chiral nanoparticle electrochemical measurement not only provides mechanistic insight into CISS-mediated electrocatalysis but also establishes a design principle for the development of highly efficient spin-selective catalytic nanomaterials.