Bismuth Sulfide Doped in Graphitic Carbon Nitride Degrades Nitric Oxide Under Solar Irradiation

This study developed and evaluated the application of bismuth sulfide doped on graphitic carbon nitride (Bi 2 S 3 @g-C 3 N 4 ) in the degradation of NO under solar irradiation. Bi 2 S 3 @g-C 3 N 4 was prepared through the grinding method. The morphological structure and chemical properties of the synthesized photocatalyst were analyzed before the degradation tests. After doping with Bi 2 S 3 , the bandgap was reduced to 2.85 eV, which increased the absorption of solar light. As a result, Bi 2 S 3 @g-C 3 N 4 achieved higher NO degradation (55%) compared to pure Bi 2 S 3 (35%) and g-C 3 N 4 (45%). The trapping test revealed that electrons were the primary species responsible for most of the NO degradation. The photocatalyst was stable under repeated solar irradiation, maintaining degradation efficiencies of 50% after five consecutive recycling tests. The present work offers strong evidence that Bi 2 S 3 @g-C 3 N 4 is stable and efficient catalyst for photocatalytic oxidation of NO over solar irradiation.