Carbon nitrides are emerging as an important class of materials with a variety of technical applications The focus of this study are polytriazine imide (PTI) materials, which are the only crystalline graphitic carbon nitrides that can be synthesised readily and reproducibly. These comprise a 2D network composed of planar layers with voids in these layers which form channels filled with Li+ and Cl- ions. A recent observation has been that the lithium and chlorinte can be removed from the PTI materials by washing with water. We can rversibly intercalate wate into these structures and the goal of this study is to establish the mobility of hydrogen within these modifoed and unmodified materials, both within channels formed by the triazine layers and between graphitic layers. Overall the the goal is to understand the influence of these guest atoms on the materials properties