A high-performance g-C₃N₅/Bi₂SiO₅ heterojunction photocatalyst induced by constructing S-scheme electron-highways

We have developed a novel S-scheme mechanism to expand the photoresponse range of Bi₂SiO₅. This study reports the successful creation of a CN/BS heterojunction photocatalyst, which is composed of g-C₃N₅ and Bi₂SiO₅. The synthesis was achieved through a simple two-step procedure, involving hydrothermal treatment and subsequent calcination. The 10% CN/BS exhibits superior photocatalytic efficiency. When exposed to visible light, the CN/BS heterojunction photocatalyst achieves a removal rate of 98.8% regarding the breakdown of Rhodamine B (RhB), outperforming Bi₂SiO₅ by a factor of 5 and g-C₃N₅ by a factor of 3. Furthermore, the removal rate for Ciprofloxacin (CIP) reaches 96.0%, which is double that of Bi₂SiO₅ and 14 times higher than that of g-C₃N₅. It is evident that the photodegradation efficiency of 10% CN/BS towards organic pollutants significantly surpasses that of the precursor composite materials. The improved photocatalytic performance is likely due to the larger specific surface area, more efficient light harvesting, and the construction of an heterojunction. Crucially, the proposition of an S-scheme hypothesis for charge transport within the CN/BS heterojunction photocatalyst marks a pivotal advancement. This concept is of substantial importance for both the theoretical exploration and the practical deployment of photocatalytic materials.