Photocatalytic Activity of Boron-Doped Bulk and Crystalline Graphitic Carbon Nitride in Visible Light-Driven Hydrogen Production

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. Under optimized conditions, the effective quantum yield of hydrogen production reaches Ф = 96 % at λopt = 405 nm.