Internal electric field-modulated charge migration behavior in atom co-sharing Bi2S3/Bi2Sn2O7 heterojunction for efficient

Developing highly efficient and visible-light responsive Bi2Sn2O7-based photocatalysts for diverse pollutants removal has attracted considerable attention. In this work, Bi2S3/Bi2Sn2O7 heterostructure photocatalyst with co-shared Bi atoms was fabricated through an in-situ sulfuration process. Experimental studies and theoretical calculations verified that the co-sharing of Bi atoms through O-Bi-S bonds across the interface and the internal electric field (IEF) between Bi2Sn2O7 and Bi2S3 can transform the type-I charge transfer process into an IEFmodulated charge migration behavior, significantly enhancing charge separation efficiency. Additionally, the incorporation of Bi2S3 broadened the visible light absorption range. Consequently, the optimal Bi2S3/Bi2Sn2O7 heterostructure exhibited a remarkable enhancement in photocatalytic tetracycline degradation activities compared to pure Bi2S3 and Bi2Sn2O7. This work provides valuable guidance for the rational design of highly-efficient Bi-based heterojunctions for photocatalytic environmental remediation.