Modification of crystalline graphitic carbon nitride for improve efficiency in photocatalytic destruction of volatile organic compounds (VOCs) under visible light irradiation

In this study, we show that the use of a mixture of melamine and oxalic acid during the synthesis of acid-treated crystalline graphitic carbon nitride samples significantly enhances its photocatalytic activity in VOCs destruction processes. The rate of photocatalytic ethanol destruction with the participation of modified crystalline graphitic carbon nitride obtained under optimal conditions is 67.1 μmol h⁻¹, which is almost twice higher than sample synthesized in the absence of oxalic acid, and is two orders of magnitude higher than the activity of bulk g–C₃N₄. The synthesized materials were characterized using XRD, FT-IR, UV–Vis, PL, SEM, and EDXA methods. The high activity of the modified carbon nitride samples is attributed to increased light absorption in the visible region of the spectrum and better crystallinity, which can lead to more efficient separation and transport of photogenerated charges. To our knowledge, the effect of the simultaneous use of melamine and oxalic acid for obtaining acid-treated crystalline graphitic carbon nitride is, shown for the first time.