Boosting the hydrogen evolution reaction of N-C@CoP through an N atom induced p-d orbital coupling

It is necessary to develop a highly efficient and stable catalyst in hydrogen evolution reaction (HER) to satisfy the demands for green hydrogen production. Herein, we find that an unconventional p-d orbital coupling exists in the interface between the N-C layer and CoP of the core-shell structured N-C@CoP, leading to a near-zero hydrogen adsorption energy of 0.16 eV. The doped N heteroatoms in carbon layer decrease the electrons on the adjacent C atoms, thus activating these C atoms as active sites for HER. Moreover, the activated three carbon atoms can interact with the Co atom in CoP, resulting in electron transfer from the p-orbital of C to the d-orbital of Co. Under this p-d orbital interaction, the N-C@CoP exhibits a eta 10 value of 35 mV and excellent long-term durability, which rivals the commercial Pt/C catalyst. This work provides a unique avenue for the design of composite catalysts with strong interaction.