Tri‐s‐triazine‐Based Crystalline Carbon Nitride Nanosheets for an Improved Hydrogen Evolution

Tri‐ s ‐triazine‐based crystalline carbon nitride nanosheets (CCNNSs) have been successfully extracted via a conventional and cost‐effective sonication–centrifugation process. These CCNNSs possess a highly defined and unambiguous structure with minimal thickness, large aspect ratios, homogeneous tri‐ s ‐triazine‐based units, and high crystallinity. These tri‐ s ‐triazine‐based CCNNSs show significantly enhanced photocatalytic hydrogen generation activity under visible light than g‐C 3 N 4 , poly (triazine imide)/Li + Cl – , and bulk tri‐ s ‐triazine‐based crystalline carbon nitrides. A highly apparent quantum efficiency of 8.57% at 420 nm for hydrogen production from aqueous methanol feedstock can be achieved from tri‐ s ‐triazine‐based CCNNSs, exceeding most of the reported carbon nitride nanosheets. Benefiting from the inherent structure of 2D crystals, the ultrathin tri‐ s ‐triazine‐based CCNNSs provide a broad range of application prospects in the fields of bioimaging, and energy storage and conversion.