Crystalline carbon nitride nanosheets for improved visible-light hydrogen evolution

We present the one-step aqueous exfoliation of the layered carbon nitride poly(triazine imide), which leads to colloidally stable suspensions of ultrathin crystalline nanosheets of 1–2 nm in height. Successful delamination was verified by AFM and TEM. The exfoliation process was investigated by ssNMR of ¹⁵N-enriched PTI nanosheets. The nanosheets show a significantly enhanced photocatalytic activity for hydrogen evolution from water as compared to their bulk counterpart, which is testament to the importance of morphology control in photocatalytic water splitting.