Advances in the Synthesis of Mesoporous Carbon Nitride Materials

Graphitic carbon nitride (g-C3N4) is a new metal-free material. Owing to its multiple unique physicochemical properties, g-C3N4 has promising applications in various research fields, including heterogeneous catalysis, photocatalysis, fuel cells, and gas storage. Compared with bulk g-C3N4 prepared via direct thermal condensation, mesoporous g-C3N4 possesses a higher surface area and abundant accessible mesoporous pores. These features expose many more surface active sites, thereby improving the performance of this material in catalysis as well as in other applications. Thermal condensation is the most convenient strategy to prepare g-C3N4 and, when fabricating mesoporous g-C3N4, one may employ hard-, soft-, or non-templating method. This paper reviews recent advances in the synthesis of mesoporous g-C3N4 using all three routes. Specifically, several crucial issues regarding the hard-templating method are discussed with regard to the synthetic mechanism associated with various precursors and the physicochemical properties of the g-C3N4 products. Novel soft- and non-templating approaches for the preparation of mesoporous g-C3N4 are also addressed and a detailed comparison to the hard-templating method is provided. Finally, future prospects for the development of mesoporous g-C3N4 materials are also assessed.