Two-dimensional g-C3N4 nanosheets-based photo-catalysts for typical sustainable processes

Graphitic carbon nitride (g-C3N4) has been widely studied as a visible light responsive photocatalyst in recent years, due to its facile synthesis, low cost, high stability, and appropriate bandgap/band positions. In this review, we firstly introduce and compare various exfoliation approaches of bulk g-C3N4 into ultrathin g-C3N4 nanosheets. Then, many modification strategies of g-C3N4 nanosheets are also reviewed, including heterojunction construction, doping, defect control, and structure design. Thereafter, the charge transfer mechanism in g-C3N4 nanosheets based heterojunctions is present, e.g., Z-scheme, S-scheme and other forms. Besides, the photocatalytic applications of g-C3N4 nanosheets based photocatalysts are summarized including environmental remediation, energy generation and storage, organic synthesis, and disinfection. This review ends with a summary and some perspectives on the challenges and new directions in exploring g-C3N4 nanosheets-based photocatalysts.