▎ 摘　　要

Mesoporous materials have attracted considerable interest due to their huge surface areas and numerous active sites that can be effectively exploited in catalysis. Here, 2D mesoporous graphitic-C3N4 nanolayers are rationally assembled on 2D mesoporous graphene sheets (g-CN@G MMs) by in situ selective growth. Benefiting from an abundance of exposed edges and rich defects, fast electron transport, and a multipathway of charge and mass transport from a continuous interconnected mesh network, the mesh-on-mesh g-CN@G MMs hybrid exhibits higher catalytic hydrogen evolution activity and stronger durability than most of the reported nonmetal catalysts and some metal-based catalysts.