CTAB-regulated Bi/Bi2WO6 heterojunction with effectively enhanced visible light photocatalytic degradation of pollutants

The surface plasmon resonance (SPR) effect demonstrated by noble metal nanoparticles has been shown to significantly boost the photocatalytic activity of semiconductors under visible light. However, the high cost limits their practical use. Recent studies have found that bismuth (Bi), a non-noble metal, exhibits similar SPR properties. In this work, we developed a new synthesis method for Bi/Bi 2 WO 6 photocatalysts using a secondary solvothermal process. The metallic Bi was reduced in situ with tartaric acid as the reducing agent, while hexadecyltrimethyl ammonium bromide (CTAB) served as a surfactant to control the morphology. The Bi/Bi 2 WO 6 heterojunction prepared with an optimal CTAB amount (0.02 g) showed much better light absorption, achieving 100% degradation of Rhodamine B (RhB) within 15 min under visible light, representing a 57% improvement over pure Bi 2 WO 6 . Recycling tests confirmed the exceptional photochemical stability and recyclability. The high performance in RhB degradation can be linked to the SPR effect of metallic Bi, which improves light absorption, produces active sites and reactive species, and speeds up carrier transfer. Additionally, the formation of the Bi/Bi 2 WO 6 Schottky heterojunction promotes carrier separation and prevents recombination of photogenerated electron–hole pairs. This study also offers a clear mechanism for the photodegradation process of the synthesized photocatalyst. Overall, this work presents a new and affordable strategy for developing high-performance photocatalytic systems, with great potential for practical applications in environmental cleanup and pollutant removal.