Non-stoichiometric semiconductors with localized surface plasmon resonance (LSPR) properties exhibit strong absorption of near-infrared (NIR) light, offering promising potential for designing sunlight-driven photocatalysts. In this study, 2D/1D S-scheme heterojunction photocatalysts made of Bi2Sn2O7 nanosheets and W18O49 nanorods were synthesized to improve the degradation of organic pollutants under visible light. The morphology, microstructure, and optical properties of the Bi₂Sn₂O₇/W18O49 heterojunction were analyzed. The Bi2Sn2O7/ W18O49-20 composite showed the highest TC degradation efficiency, removing 96 % in 2 h under visible light, which is 2.59 and 1.84 times higher than that of pristine W18O49 and pure Bi2Sn2O7, respectively. Kinetic studies revealed that degradation followed pseudo-first-order kinetics, with the rate constant for the composite being significantly higher than that for the individual components. Improved charge separation and transfer across the heterojunction were confirmed by photoluminescence and photocurrent measurements. Scavenger tests identi fied holes (h⁺) and superoxide radicals (•O2⁻) as the main reactive species responsible for degrading TC. Addi tionally, the catalyst demonstrated good stability and could be reused multiple times, indicating its practical potential. The Bi2Sn2O7/W18O49 composite was developed to effectively remove TC from aqueous solutions, presenting a novel approach for wastewater purification using materials with LSPR properties.
