To facilitate the accessibility of clean energy, the design of innovative materials to store and produce energy for continuous usage is crucial.^1–3  The increasing demands for, but reducing supply of, old-style batteries and fuel cells have motivated research to develop environmentally-friendly, abundant, and cheap energy storage and production devices.¹  Different catalysts or materials' electrodes have been used to enhance the storage and production efficiencies. Graphitic carbon nitride (gCN)-based devices have attracted attention due to their interesting characteristics, structures, and performance.^1,4,5  Graphitic carbon nitrides (gCNs) are one of the earliest used synthetic polymers in the scientific arena and have various chemical and structural properties. Some current reports in the literature have been described as reporting on g-C₃N₄ materials; however, this is not always the case. Most of the compounds discussed do not have a ratio 3 : 4 for C : N. They usually contain large contents of O and H atoms.⁶  gCNs attract interest as robust metal-free compounds. An exciting class of gCNs involves graphene-like carbons, graphitic carbon, or carbon nanotubes. They possess metallic properties^7,8  and can be synthesized with different N content.^7,9  The largest CNs class includes various polymeric or graphitic systems with chemical compositions between C₃N₄ and C₂N₃H in the phase diagram of ternary C–N–H.¹  They can be synthesized by condensing melamine, urea, or dicyandiamide following thermal treatment at 500–700 °C.¹⁰  Research into these compounds has become a fascinating hotspot in different fields, including water purification,^11,12  photocatalysis,^13–15  fuel cells,^16,17  and gas conversion reactions, on account of the facile preparation, earth-abundant nitrogen (N) and carbon (C), and environmentally–friendly properties.^18–27