molecular hydrogen

The current state of research on photocatalytic systems based on crystalline graphitic carbon nitride (CCN) for H₂ evolution from aqueous solutions of electron-donating substrates is considered. Methods of CCN synthesis and photocatalytic properties of different samples of CCN-undoped with a controlled defect structure and doped with metals and non-metals are discussed. Possible directions for further research of such CCN-based photocatalytic systems are outlined.

Boron-doped bulk samples of graphitic carbon nitride (B-g-C₃N₄) were synthesized by pyrolysis of melamine-boric acid mixtures, followed by their subsequent annealing in a eutectic melt of potassium and lithium chlorides, resulting in the formation of crystalline g-C₃N₄ (B-CGCN). The obtained materials demonstrate significantly higher activity in hydrogen evolution from aqueous-ethanolic solutions under visible light irradiation compared to undoped g-C₃N₄ and CGCN.