A Promoted Charge Separation/Transfer System from Cu Single Atoms and C N Layers for Efficient Photocatalysis.

Establishing highly effective charge transfer channels in carbon nitride (C N ) for enhancing its photocatalytic activity is still a challenging issue. Herein, for the first time, the engineering of C N layers with single-atom Cu bonded with compositional N (CuN ) is demonstrated to address this challenge. The CuN is formed by intercalation of chlorophyll sodium copper salt into a melamine-based supramolecular precursor followed by controlled pyrolysis. Two groups of CuN are identified: in one group each of Cu atoms is bonded with three in-plane N atoms, while in the other group each of Cu atoms is bonded with four N atoms of two neighboring C N layers, thus forming both in-plane and interlayer charge transfer channels. Importantly, ultrafast spectroscopy has further proved that CuN can greatly improve in-plane and interlayer separation/transfer of charge carriers and in turn boost the photocatalytic efficiency. Consequently, the catalyst exhibits a superior visible-light photocatalytic hydrogen production rate (≈212 µmol h /0.02 g catalyst), 30 times higher than that of bulk C N . Moreover, it leads to an outstanding conversion rate (92.3%) and selectivity (99.9%) for the oxidation of benzene under visible light.