Flower-like Bi2S3–In2S3 heterojunction for efficient solar light induced photoreduction of Cr(VI).

To develop Bi 2 S 3 -based heterojunction for efficient solar light induced photoreduction of Cr(VI), flower-like Bi 2 S 3 –In 2 S 3 composites consisted of nanorods were prepared via a microwave-assisted hydrothermal route. In contrast with pure Bi 2 S 3 , Bi 2 S 3 –In 2 S 3 composites exhibited the enhanced photoreduction activity while the decreased adsorption capacity for Cr(VI) removal. The best removal efficiency of 70 mg L−1 Cr(VI) solution (99.86%) was achieved by the optimal 3-Bi 2 S 3 –In 2 S 3 with a Bi/In molar ratio of 4:1 within 140 min. It's ascribed to the narrow band gap for strengthened visible-light response, the tight interface between Bi 2 S 3 and In 2 S 3 for rapid transfer and separation of charge carriers, and the enough S vacancies for highly-efficient active sites of adsorption-photoreduction. However, the long-term photo-corrosion resulted in the slightly inferior reusability of 3-Bi 2 S 3 –In 2 S 3 under solar light irradiation after five cycles. [Display omitted] • Flower-like Bi 2 S 3 –In 2 S 3 was prepared by microwave-assisted hydrothermal route. • Bi 2 S 3 –In 2 S 3 composite presents the enhanced removal efficiency of Cr(VI). • Narrow band gap of Bi 2 S 3 –In 2 S 3 promotes the carrier separation and migration. [ABSTRACT FROM AUTHOR]