Molten salts-assisted synthesis is widely used in the construction of high efficiency graphitic carbon nitride (g-C3N4) photocatalysts, and two isotypes g-C3N4 have been synthesized by such method, namely poly (heptazine imide) (PHI) (triazine (PTI). However, understanding structural changes taking place during molten salt process structure–activity relationship polymorphs remain blurred. Herei...