Trace samarium doped graphitic carbon nitride photocatalytic activity toward metanil yellow dye degradation under visible light irradiation

In this study, graphitic carbon nitride (g-C3N4) is synthesised under the optimised conditions and doped with samarium. The synthesised photocatalysts were characterized using appropriate techniques and applied for the photodegradation of metanil yellow (MY) dye under visible light irradiation. The UV-vis spectrometry and UHPLC/Q-TOF-MS were used to determine and identify MY photodegradation rate and intermediate products, respectively. From this study, the highest photodegradation of MY achieved after 6 h reaction time was 93 and 87 % using samarium doped g-C3N4 at pH 3 and 6.4, respectively. From the pH studies, acidic pH was found convenient for fast photodegradation. While scavenger studies showed superoxide radicals are the main species responsible for photodegradation of MY. Furthermore, the intermediate products were identified and the photodegradation mechanisms are proposed. Overall, based on the amount of photodegraded MY and reusability studies, the synthesised photocatalyst is efficient and stable for MY photodegradation.