<p>Plasmon-assisted graphitic carbon nitride (g-C₃N₄)–based nanomaterials have emerged as efficient photocatalysts for environmental remediation, particularly in degrading antibiotics, dyes, pesticides, and heavy metals from wastewater. The plasmonic metals, such as Ag, Au, Cu, or Pt, were formed by various routes and decorated on host matrices, including polymeric organic frames, glass composites, and 2D structures like graphene, carbon borides, carbon nitrides, and metal sulfides. The present review article presents a systematic methodology for developing plasmonic Ag and Au nanoparticle–based 2D carbon nitrides (CN)/graphitic carbon nitrides (g-C₃N₄) nanomaterials. Moreover, this review also compiles recent advances in the synthesis, structural modifications, and photocatalytic mechanisms of Ag- and Au-doped 2D carbon nitrides. The incorporation of noble metal nanoparticles enhances surface plasmon resonance, which promotes visible light absorption, bandgap tuning, and charge separation efficiency. Studies have revealed significantly improved degradation rates of pollutants up to 97% for antibiotics and over 98% for dyes, through synergistic interactions with dopants such as Cu, Pd, and rGO. Particularly, Ag-g-C₃N₄ composites achieved a reduction of up to 99.9% of Cr(VI) to Cr(III), while Pd/g-C₃N₄ nanostructures exhibited high selectivity and reusability. The review also emphasizes the impact of molecular structure on degradation efficiency and outlines future challenges in catalyst stability, scalability, and performance optimization. These findings emphasize the promise of plasmon-enhanced 2D g-C₃N₄ materials in sustainable wastewater treatment technologies.</p>