Influence of Heating Rate on the Structural Optimization of g‐C 3 N 4 for High‐Efficiency Photocatalytic Degradation of Naphthol Green and Ternary Dye Pollutants

ABSTRACT Graphitic carbon nitride (g‐C 3 N 4 ) is a promising metal‐free photocatalyst due to its visible‐light activity, chemical stability, and tuneable electronic structure. In this study, g‐C 3 N 4 was synthesized via a controlled pyrolysis route with precise heating‐rate modulation, enabling tailored polymerization, and enhanced structural ordering. Structural analysis revealed improved crystallinity and interlayer stacking, while surface morphology image depicts ultrathin sheets that facilitate rapid charge transport. Elemental composition confirmed uniform C/N distribution, and spectral analysis validated intact heptazine frameworks. UV–Vis studies revealed a red shift and a reduced band gap, indicating improved visible‐light absorption and efficient charge separation. Further, optimized g‐C 3 N 4 exhibited excellent photocatalytic activity, degrading 98.7% of Naphthol Green within 5 min in the presence of Conc.HNO 3 . Also, the mixed‐dye system achieved 91.6% degradation of Congo Red, 97.2% of Rhodamine B, and 97.4% of Methylene Blue within 90 min, respectively. This work demonstrates heating‐rate engineering as an effective strategy for tailoring g‐C 3 N 4, enabling rapid and efficient degradation of single‐ and multidye pollutants, with strong potential for wastewater treatment applications.