Photocatalytic removal of pollutants via exfoliated carbon nitride: Advances and challenges

The current level of water contamination, the reduction of freshwater sources, and new regulations enforce the need for efficient water remediation alternatives. Using graphitic carbon nitride (g-C 3 N 4 ) in the photocatalytic degradation of contaminants of emerging concern (CECs) is a treatment alternative with proven good results. However, g-C 3 N 4 typical low surface area caused by the structure of the stacked layers hinders further improvement in its performance. Catalyst exfoliation is an interesting method to overcome these known drawbacks, aiming at the delamination and separation of the packed sheets of the material. Different techniques may be applied, such as chemicals, temperature, and equipment, to break the weaker interactions that connect the catalyst’s layers. Within this review, the recent approaches for g-C 3 N 4 exfoliation and their application for contaminants are evaluated. The exfoliation methods and their effects on key properties of the catalyst are critically analyzed. • g-C 3 N 4 is a promising visible-light-driven catalyst, but its dense structure requires optimization. • Exfoliation is an easy alternative to improve surface area and other parameters to boost g-C 3 N 4 activity. • Multiple exfoliation methods may be applied, with different effects over the catalyst structure. • A critical comparison of exfoliation methods has been made, aiming for a better selection in future applications.