Cu single atoms embedded on hollow g-C3N4 nanospheres with enhanced charge transfer and separation for efficient photocatalysis

Establishing an effective charge transfer mechanism in carbon nitride (g-C3N4) to enhance its photocatalytic activity remains a limiting nuisance. Herein, the combination design of a single Cu atom with hollow g-C3N4 nanospheres (Cu-N3 structure) has been proven to offer significant opportunities for this crucial challenge. Moreover, this structure endows two pathways for charge transfer in the reaction, namely, the N atoms in the three-dimensional planar structure are only bonded with a single Cu atom, and charge transfer occurs between the plane and the layered structure due to the bending of the interlayered g-C3N4 hollow nanospheres. Notably, Cu-N3 and hollow nanosphere structures have been certified to greatly enhance the efficiency of photogenerated carrier separation and transfer between the layers and planes by ultrafast spectral analysis. As a result, this catalyst possesses unparalleled photocatalytic efficiency. Specifically, the hydrogen production rate up to 2040 µmol h−1 g−1, which is 51 times that of pure C3N4 under visible light conditions. The photocatalytic degradation performance of tetracycline and oxidation performance of benzene is also expressed, with a degradation rate of 100%, a conversion of 97.3% and a selectivity of 99.9%. This work focuses on the structure-activity relationship to provide the possibilities for the development of potential photocatalytic materials.