Recently, various lightweight materials with diverse nanomorphologies that contain heteroatoms such as nitrogen, boron, or fluorine have been actively pursued because of their unusual properties, such as in catalytic applications or as semiconductors. [1] For example, ordered and disordered modifications of carbon nitride (C 3 N 4 ) extend the property profile of carbon nanostructures and have numerous potential areas of applications ranging from semiconductors to fuel cells. [1a] A large number of reports deals with the synthesis of different modifications of bulk C x N y materials. [2] The synthesis of these nitrogen-rich species generally includes thermal condensation of nitrogen-rich precursors, often from molecules containing or generating triazine rings. For example, through a solid-state reaction of 2,4,6-triamino-1,3,5-triazine with 2,4,6-trichloro-1,3,5-triazine at high pressure and high temperature, Wolf and co-workers obtained a well-characterized and highly crystalline graphitic carbon nitride derivative. [3] However, it was shown that the more ideal bulk carbon nitride solids perform rather weakly in some catalytic processes, while more disordered, polymeric versions showed nice activity, as structural defects or surface terminations seemed to play a key role for the catalytic activation. [4] To enhance the performance of carbon nitride both as a support and as a catalyst, the specific surface had to be enhanced, and nanocasting with hard templates using porous silicas has been explored recently for the replication of porous carbon nitride materials with controlled mesopore structures.