Enhanced g-C3N4 for sustainable solar degradation of 1,3-diphenylguanidine (DPG) in wastewater: Investigating the effects of precursor, temperature, and potassium doping

Abstract

Sustainable methods for wastewater treatment offer promising solutions to address pressing environmental challenges. This study investigates the potential of graphitic carbon nitride (g- C3N4) as an environmentally friendly photocatalyst for wastewater treatment. The research involves the systematic exploration of various precursors (melamine, urea, and dicyanamide), different polymerization temperatures (500, 550, and 600 °C), and varying K-doping levels (1 %, 3 %, and 5 % KOH), providing valuable insights into the properties of g-C3N4. This study marks a significant advancement by reporting, for the first time, the successful degradation of 1,3-Diphenylguanidine (DPG) in wastewater. UCN-K1, a urea-derived g-C3N4 doped with 1 % KOH, displayed exceptional performance, achieving nearly 95 % DPG removal within 6 h under solar radiation and utilizing a remarkably low dose (0.1 g/L). Furthermore, the research offers a comprehensive understanding of reaction kinetics, a detailed analysis of K-doping effects, and profound insights into the degradation mechanism of DPG, including potential transformation products.