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

Abstract

This study developed and examined the application of bismuth sulfide doped on graphitic carbon nitride (Bi2S3@g-C3N4) in the degradation of NO under solar irradiation. Bi2S3@g-C3N4 was prepared through the calcination method. The morphological structure and chemical properties of the synthesized photocatalyst were analyzed before the degradation tests. After doping with Bi2S3@g-C3N4, the bandgap was reduced to 2.76 eV, which increased the absorption of solar light. As a result, the Bi2S3@g-C3N4 achieved higher NO degradation (55%) compared to pure Bi2S3 (35%) and g-C3N4 (45%). The trapping test revealed that the 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 Bi2S3@g-C3N4 is a stable and efficient catalyst for the photocatalytic oxidation of NO over solar irradiation.