Hollow Cobalt Phosphide with N-Doped Carbon Skeleton as Bifunctional Electrocatalyst for Overall Water Splitting.

The development of cost-effective, high-performance, and robust bifunctional electrocatalysts for overall water splitting remains highly desirable yet quite challenging. Here, by selecting appreciate precursors of dopamine and a Co-containing metal-organic framework of ZIF-67, we subtly couple their reaction processes to develop a facile approach for the synthesis of a hollow CoP nanostructure with N-doped carbon skeleton (H-CoP@NC). Benefiting from the highly porous nanostructure and conductive carbon skeleton, H-CoP@NC is capable of working as highly active and durable bifunctional electrocatalyst for both hydrogen and oxygen evolution reaction. When further used as the electrocatalyst for overall water splitting, H-CoP@NC delivers excellent activity (cell voltage of 1.72 V at a current density of 10 mA cm), close to that of the noble-metal-based benchmark catalyst couple of Pt/C||RuO. Our work thus provides new insights into the development of transitional metal phosphides based hollow hybrid nanostructures, particularly those with multiple functionalities in sustainable energy conversion technologies and systems.