Enhanced d-π overlap in a graphene supported Ni/PtNi heterojunction for efficient seawater hydrogen evolution.

d-π overlap, which represents overlap between metal-d and graphene-π orbitals to facilitate electron transfer, has rarely been reported. Ni/PtNi-G 2 exhibits exceptional performance in seawater hydrogen evolution due to the electron-rich surface on Pt resulting from enhanced d-π overlap and subsequent electron transfer from graphene and Ni to Pt.