Atomically-dispersed NiN4–Cl active sites with axial Ni–Cl coordination for accelerating electrocatalytic hydrogen evolution

The NiN 4 –Cl SAs/N–C electrocatalyst consisting of NiN 4 –Cl active sites with axial Ni–Cl coordination was synthesized. The axial Cl-coordination modulates the electronic configuration of Ni–N 4 sites and enhances the interaction of Ni–H efficiently.