Boosting the Selectivity in Oxygen Electrocatalysis Using Chiral Nanoparticles as Electron-Spin Filters

Controlling the electron spin of oxygen-containing intermediates is crucial for efficient oxygen electrocatalysis toward clean energy technologies such as fuel cells and water electrolysis. Current strategies for controlling the electron spins rely mainly on tuning the chemical structure of the oxygen electrocatalyst, which is often hardly achieved for metal and oxide electrocatalysts. The chiral-induced spin selectivity (CISS) effect, a significant discovery in chiral spintronics, represents an alternative approach for tuning the spin selectivity of oxygen electrocatalysts. Here we demonstrate the use of intrinsic chiral nanoparticles as electron-spin filters to tune the selectivity in oxygen electrocatalytic reactions. Chiral Au nanoparticles with a concave vortex cube structure were employed as the chiral substrate, exhibiting highly tunable optical chirality and intriguing CISS-like effect. As model systems, the catalytically active components such as Pt or Ni(OH) 2 are overgrown onto chiral Au nanoparticles to construct the chiral hybrid electrocatalysts. Remarkably, both cases show chirality-dependent tunable activities over oxygen reduction/evolution reactions, respectively. The insights gained from this work not only shed light on the underlying mechanisms dictating the CISS-enhanced oxygen electrocatalysis by chiral nanoparticles but also provide an important knowledge framework that guides the rational design of chiral electrocatalysts toward oxygen electrocatalysis.