Comparative study of KF, KCl and KBr doped with graphitic carbon nitride for superior photocatalytic degradation of methylene blue under visible light

In this study potassium salts such as KF, KCl and KBr were doped onto g-C₃N₄ to form KX-g-C₃N₄ (X = F, Cl and Br) via a thermal method. The KX-g-C₃N₄ was characterized by various instrumentation techniques such as UV–visible, FT-IR, XRD, Photoluminescence, TGA, BET, Raman, SEM, EDAX, HR-TEM, and Zeta potential. KX-g-C₃N₄ was explored for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Among them, KF-g-C₃N₄ showed excellent photocatalytic degradation of methylene blue (MB) under visible light irradiation. The KF-g-C₃N₄ significantly reduced the electrons–holes recombination rate when compared to KCl-g-C₃N₄, KBr-g-C₃N₄ and g-C₃N₄. The photocatalytic degradation mechanism was also studied with KF-g-C₃N₄.