One-step construction of sulfur-vacancy-rich SnS/Bi2S3 Z-scheme heterostructure photocatalyst for significant removal of hazardous Cr(VI)

The construction of green and efficient photocatalysts for the treatment of heavy metals in wastewater through simple strategies is still an extremely huge challenge. Herein, SnS/Bi₂S₃ Z-scheme heterostructure photocatalyst with abundant sulfur vacancies was fabricated by one-pot hydrothermal approach and exploited for the efficient elimination of hexavalent chromium (Cr(VI)). Due to the tight contact interface of the in-situ heterostructures, charge transfer was carried out quickly and photogenerated carrier separation was accelerated. Moreover, the unique charge transmission path of the Z-scheme can efficiently inhibit the reorganization of active carriers. The abundant sulfur vacancies can further improve the photogenerated carrier separation efficiency. SnS/Bi₂S₃-2 can achieve effective reduction of Cr(VI) with the efficiency of 91.6 % under 30 min visible light illumination. This study provides a promising photocatalyst for the treatment of chromium hexavalent sewage, and effectively promotes the exploration of one-step construction of heterostructure photocatalyst in the field of water environment remediation.