Chlorine-assisted synthesis of CuCoS@(Cu,Co)Cl(OH) heterostructures with an efficient nanointerface for electrocatalytic oxygen evolution.

The demand for sustainable energy sources urges the development of efficient and earth-abundant electrocatalysts. Herein, chlorine assisted ion-exchange and in-situ sulfurization processes were combined to construct CuCoS@(Cu,Co)Cl(OH) heterostructures from Cu(OH) nanoarrays. Chlorine element in the cobalt source stimulated the formation of (Cu,Co)Cl(OH) precursor, and further facilitated partial transformation of the precursor to CuCoS on the surface to achieve composite structure.