Na/Cu‐Doping Engineering of Carbon Nitride for High‐Performance Visible‐Light Degradation of Iopamidol

Visible-light-driven photocatalytic generation of hydroxyl radicals provides a sustainable pathway for the photodegradation of emerging contaminants. Particularly, carbon nitride (g-C3N4) is a promising photocatalyst for the removal of emerging contaminants; however, it suffers from a limited surface area and a bandgap that restricts its visible-light photocatalytic efficiency. To overcome these limitations, this study presents a novel copper–sodium codoped graphitic carbon nitride (NaCu-g-C3N4) photocatalyst with enhanced visible-light photocatalytic activity tested for the degradation of Iopamidol, a persistent and toxic pollutant resistant to conventional wastewater treatment plants. The codoping of Na and Cu was strategically employed to reduce the bandgap energy, enhance visible-light absorption, and increase the surface area, thereby improving the photocatalytic activity of carbon nitride. When combined with the oxidizing agent H2O2, the system accelerated the formation of oxidizing radicals. The synergy of NaCu-g-C3N4 and H2O2 yielded 82.3% degradation of Iopamidol within 120 min under visible light at pH 3, marking the highest and first successful reported visible-light-driven degradation of Iopamidol. These findings highlight the potential of NaCu-g-C3N4 as a cost-effective semiconductor photocatalyst for the efficient and sustainable removal of persistent pollutants.