Increasing electron transfer and light absorption in graphited nanocarbon-conjugated g-C3N4 nanosheet heterostructure for photocatalytic hydrogen evolution

Accelerating the charge separation and transfer as well as increasing the visible light absorption is of great importance for photocatalysts to realize efficient photocatalytic hydrogen evolution via water splitting. Herein, for the first time, we fabricated in-plane graphited nanocarbon-conjugated polymeric carbon nitride (GNC-C3N4) nanosheet heterostructure photocatalyst from melamine and hexaketocyclohexane octahydrate mixture via an amino-carbonyl reaction. The incorporation of GNC into conjugate network of C3N4 can not only dramatically enhance the light harvesting but also significantly promote the charge separation and transfer by the built-in electric field and intimate interface in the coplanar GNC-C3N4 heterostructure. Accordingly, the optimal GNC-C3N4 photocatalyst demonstrates a more than 15-fold enhancement for photocatalytic hydrogen evolution from water under visible light irradiation, compared to C3N4.