Carbon Dots–Implanted Graphitic Carbon Nitride Nanosheets for Photocatalysis: Simultaneously Manipulating Carrier Transport in Inter- and Intralayers

摘要

Carbon dots (CDs) present unique photoinduced charge transfer and reservoir properties, showing promising application potential in photocatalysis. The in situ preparation of CDs in a graphitic carbon nitride (g-C_3N_4) matrix provides not only a new approach for electronic structure modulation and heterostructure construction but also an effective way to improve their photocatalytic performance. However, incorporating CDs into ultrathin g-C_3N_4 remains a challenge. Moreover, simultaneously tuning their carrier transport in inter- and intralayers is difficult but significant for their application as efficient photocatalysts. Herein, an unprecedented Se-chaperoned thermal polymerization method for the synthesis of zero-dimensional CD-implanted g-C_3N_4 nanosheets (CCNS) is reported. The CCNS simultaneously facilitate carrier transport and suppress recombination because of the seamless bonding heterostructure of CDs within the in-plane domains of the g-C_3N_4 nanosheets. Accordingly, the photocatalytic rates of water splitting for H_2 evolution and CO_2 reduction are enhanced 3.1 and 4.1 times, respectively. In addition, the photocatalytic RhB degradation efficiency dramatically increases 18 times. This work presents a promising solution to solving the current worldwide energy shortage and environmental pollution issues.