Improved Photocatalytic H₂ Evolution over G-Carbon Nitride with Enhanced In-Plane Ordering

A series of rod-like porous graphitic-carbon nitrides (short as CNs) with enhanced in-plane ordering have been fabricated through self-assembled heptazine hydrate precursors for the first time. By controlling the calcination of the preformed precursors with different temperature-rising rates, the resulted CNs (SAHEP-CNs-1) with the most ordered and least stacked graphitic planar are showing a tremendously improved hydrogen evolution rate of 420 μmol h^-1 under visible light and a remarkable apparent quantum efficiency of 8.9% at 420 nm, which is among the highest values for C₃ N₄ -related photocatalysts in the literature. This work discloses that enhancing in-plane ordering is one critical factor for improving the photocatalytic H₂ evolution of carbon nitride, which is an effective solution to prolong the lifetime of charge carriers by accelerating the charge transport and separation within the graphitic planar. This finding would present a facial strategy for the designing of efficient organic semiconductors for photocatalysis.