▎ 摘　　要

Efficient water splitting demands highly active, low cost, and robust electrocatalysts. In this study, we report the synthesis of penroseite (Ni,Co)Se-2 nanocages anchored on 3D graphene aerogel using Prussian blue analogues as a precursor and further their applications in overall water splitting electrolysis. The synergy between the high activity of (Ni,Co)Se-2 and the good conductivity of graphene leads to superior performance of the hybrid toward the water splitting in basic solutions. The (Ni,Co)Se-2-GA only requires a low cell voltage of 1.60 V to reach the current density of 10 mA cm(-2), making the (Ni,Co)Se-2-GA hybrid a competitive alternative to noble metal based catalysts for water splitting.