Sub-grain Boundaries by Cold-Rolling Copper Nanoparticles for Boosting Alkaline HER

Abstract

We demonstrate a cold-rolling strategy that generates a high density of sub-grain boundaries in Cu nanoparticles, predominantly at particle interfaces. Experimental and theoretical analyses show that these sub-grain boundaries act as major contributing sites, facilitating interfacial water dissociation and lowering the energy barrier, thereby enhancing alkaline HER performance.