▎ 摘　　要

Graphitic C3N4 (g-C3N4) is used as a low-cost organic oxygen evolution reaction (OER) electrocatalyst. The integration of ultrathin g-C3N4 nanosheets with graphene leads to g-C3N4/graphene composites with high OER activity and good durability. X-ray photoelectron spectroscopy (XPS) studies suggest that the OER activity results from pyridinic-N-related active sites. This catalyst provides an alternative to OER catalysts based on transition metals.