▎ 摘　　要

The two-dimensional catalyst for water splitting is a hot topic in this decade, since searching for low-cost candidates to replace rare Pt-based catalysts is the key to solving the energy issue. In this work, the electronic structure of graphene is well adjusted with hybridized halogen and oxyacid radical (SO4, SeO4, MoO4) groups, which improves its catalytic activity for water splitting. Especially, the G-SO4 shows high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Moreover, the catalytic activity of functionalized graphene is strongly dependent on the interfacial charge transfer and pz band center of carbon active sites. Generally, our work provides a new idea for predicting and designing potential carbon-based catalysts for overall water splitting.