Bridging the plasmonic copper and N-Doped graphitic carbon by embedding conductive honeycomb-like carbon sphere mediators for highly efficient photocatalytic hydrogen evolution

Improving the separation of photogenerated electron-hole pairs is considered an effective approach to enhance the photocatalytic activities. Herein, Cu nanoparticles (NPs) are loaded on N-doped graphitic carbon (NGC)/honeycomb-like carbon sphere (HCS), where HCSs is dispersed on the NGC layer, obtaining a novel NGC/HCS/Cu NPs (GCPC) hierarchical structure for photocatalytic hydrogen evolution under simulated sunlight. The intercalation of HCS as the interface mediator plays an important role in effectively enhancing the migration and separation of the hot electrons generated by the surface plasmon resonance (SPR) of Cu NPs for water photosplitting. Interestingly, the near-infrared photoluminescence for GCPC was observed under 500 nm light excitation. The optimized NGC/HCS/Cu NPs hierarchical structure reveals a remarkable photocatalytic H₂ evolution rate (2.721 mmol g^-1 h^-1), which is much higher than those of NGC/Cu NPs (VCPC0.25) and carbonized carbon sphere/Cu NPs (GCC), and exhibits high stability after multiple photocatalytic cycles.