Preparation and Modification of Crystalline Carbon Nitride

As a typical two-dimensional organic polymeric semiconductor photocatalyst, graphitic carbon nitride (g-C3N4) has attracted much attention due to its visible-light-responsive property, chemical structure stability and excellent biocompatibility, indicating its promising applications in fields of energy and environment. However, there are many defects both in the bulk and on the surface of g-C3N4 due to the incomplete polymerization, which become the charge recombination centers, resulting in a poor photoreactivity. Recently, the study on the high-photoreactive crystalline carbon nitride (CCN) has elicited considerable attention. In this mini review paper, typical methods in fabrication of CCN, together with the modification strategies, are summarized. The five methods in synthesizing CCN include traditional molten, precursor-preheated molten, solid salt, solvothermal reaction and protonation synthesis, and the modification strategies include defects engineering, morphology-controlling, single-atom modification and materials hybridization. We mainly focuse on the introduction of principles, structure properties and photocatalytic performances of CCN. Finally, the methods in preparation and modification of CCN are commented, and the study of CCN in the future is also outlooked.