Facile synthesis of novel three-dimensional Bi2S3 nanocrystals capped by polyvinyl pyrrolidone to enhance photocatalytic properties under visible light

Abstract Exploitation of novel photocatalysts for highly efficient degradation of organic dyes and reduction of hexavalent chromium is of significance to reduce environmental pollution. Herein, a novel three-dimensional flower-like Bi2S3 nanocrystals composed of two-dimensional Bi2S3 nanosheets were prepared by one-pot hydrothermal method with polyvinyl pyrrolidone (Mw = 1300000) as a capping agent. The experimental results show that polyvinyl pyrrolidone has evident enhanced effect on the photocatalytic performance of Bi2S3, and the polyvinyl pyrrolidone modified three-dimensional Bi2S3 (Bi2S3-1) displays extraordinary catalytic activity for photodegradation of rhodamine B and photoreduction of Cr(VI) under visible light. The rates of photodegradating rhodamine B and photoreducing Cr(VI) with Bi2S3-1 can reach 93.9% in 30 min (k = 0.07675 min−1) and 95.2% in 5 min (k = 0.47351 min−1), respectively. The photocatalytic performance of polyvinyl pyrrolidone modified three-dimensional Bi2S3 is much better than those of previously reported bismuth-based nanostructures. This work provides a new insight into the development of inorganic photocatalysts for both degradation of organic dyes and reduction of heavy metal ions.