Hexagonal hollow porous tubular graphitic carbon nitride with rich-π-electrons for enhanced photocatalytic hydrogen evolution

It is greatly desirable to simultaneously modulate the micromorphology and pi-electrons of graphitic carbon nitride (GCN) to achieve highly photocatalytic hydrogen (H-2) evolution activity. Here, hexagonal hollow porous tubular GCN with rich-pi-electrons (GCNT) was successfully fabricated via a simple self-assembly engineering coupled with a thermal polymerization approach. Compared with bulk GCN, incorporation of pyridine groups into the skeleton of GCNT not only significantly increased the specific surface area, exposed more active sites, and improved utilization of photons, but also expanded the pi-electrons density, optimized the electronic band structure, promoted the rapid separation/migration of charge carriers. As a result, GCNT exhibited superior photocatalytic activity, with a H-2 evolution rate of 20.1 mu mol h(-1) under visible light irradiation (lambda > 420 nm), which was approximately 6.1 times higher than that of bulk GCN. The enhancement photocatalytic activity is ascribed to the hexagonal hollow porous tubular morphology and rich-pi-electrons synergistic effect. The present study proposes a promising strategy for exploiting the highly efficient photocatalytic H-2 evolution of GCN by modulating microscopic morphology and pi-electrons.