▎ 摘　　要

Design and synthesis of efficient photocatalysts for hydrogen production via water splitting are of great importance from both theoretical and practical viewpoints. Many metal-based semiconductors have been explored for this purpose in recent decades. Here, for the first time, an entirely carbon-based material, bulk three-dimensionally cross-linked graphene (3DG), has been developed as a photocatalyst for hydrogen production. It exhibits a remarkable hydrogen production rate of 270 mu mol.h(-1).g(cat)(-1) under full-spectrum light via a hot/free electron emission mechanism. Furthermore, when combined with the widely used semiconductor TiO2 to form a TiO2/3DG composite, it appears to become a more efficient hydrogen production photocatalyst. The composite achieves a production rate of 1,205 mu mol.h(-1).g(cat)(-1) under ultraviolet-visible (UV-vis) light and a 7.2% apparent quantum efficiency at 350 nm due to the strong synergetic effects between TiO2 and 3DG.