In-situ constructing Bi2S3 nanocrystals-modified Bi12O17Cl2 nanosheets with features of rich oxygen vacancies and reinforced photocatalytic performance

For the first time, a facile in-situ anion exchange strategy by using pure carbon disulfide (CS2) as a direct sulfur source was adopted to construct various Bi2S3 nanocrystals-modified two-dimensional (2D) Bi12O17Cl2 nanosheets binary composites at room temperature. The preparation was a simple, energy-efficient, and easy operation procedure in comparison to conventional treatments. These bi-phased composites were thoroughly characterized by a batch of analytical techniques. FT-IR, Raman, EDS, and XPS spectra verified the coexistence of both components in composites, where Bi2S3 was evenly distributed on exposed surface of Bi12O17Cl2 nanosheets as irregular-shaped nanocrystals to create intimate interfacial contacts at heterojunction domains by TEM and HRTEM observations. Interestingly, oxygen vacancies could be generated during sulfuration processes. The as synthesized Bi2S3-Bi12O17Cl2 composites exhibited reinforced photocatalytic removal efficiency of Rhodamine B and tetracycline hydrochloride under visible light irradiation, mainly attributing to appropriate phase composition, suitable morphological structure, strengthened visible-light response, presence of oxygen vacancies, and efficient separation of charge carriers driven by the well -matched band structures of both parties. Moreover, a feasible photocatalysis mechanism was presumed and reusability test was also carried out. This study shed light on the construction of robust Bi2S3-containing composites with ample oxygen vacancies and enhanced photocatalytic capacities by a facile procedure under moderate conditions.