Structural engineering and nitrogen doping of graphitic carbon nitride for photocatalytic degradation of organic pollutants under visible light

The ultrathin and porous graphitic carbon nitride (g-C₃N₄) nanosheets with structural design and abundant nitrogen dopants were synthesized via a one-step calcination procedure. The exfoliated and doped g-C₃N₄ (NT-CN) displayed enhanced photocatalytic activity for degradation of hydrochloride tetracycline and rhodamine B degradation in the complex water matrixes with different pH values or even in the presence of various anions (Cl⁻, CO2–3, NO- 3, and SO2–4). N-doped porous structure provided an extremely high surface area and enhanced basicity, enabling NT-CN catalyst to adsorb the abundant active species and pollutants. Moreover, NT-CN exhibited a wide band gap with a strong negative CB minimum of −1.07 eV that facilitated the formation of more photoexcited electrons. During the reaction process, the generated electrons reacted with dissolved O₂ to produce the ·O₂⁻ species, and then transformed into highly reactive and stable ¹O₂ species, which play a predominant role in eliminating pollutants.