One-step hydrothermal synthesis of N-S-GQDs/Bi2S3 microrods with highly photocatalytic performance for Cr(VI) reduction

Abstract Develop new method to deal with heavy metal pollution is one of important topics in environmental protection. In this work, we prepared novel N,S co-doped graphene quantum dots (N,S-GQDs) modified Bi2S3 microrods (N,S-GQDs/Bi2S3) via a facile one-step hydrothermal method. In hydrothermal process, the produced N,S-GQDs were synchronously doped into Bi2S3 crystals. The introduction of N,S-GQDs largely increases the specific surface area of the catalyst and accelerates the migration of photogenerated carriers. Moreover, N,S-GQDs doping significantly enhanced the light absorption of Bi2S3 crystals in the range of 200–800 nm. The photocatalytic performance of the prepared catalyst was evaluated by photocatalytic reduction removal of aqueous Cr(VI). The results showed that the performance of the composite N,S-GQDs/Bi2S3 microrods was significantly improved compared with bare Bi2S3. With optimum molar ratio of N,S-GQDs to Bi2S3, the reduction rate for Cr(VI) to Cr(III) over N,S-GQDs/Bi2S3 reaches 70.3% in 80 min. This work provides a simple route for constructing graphene quantum do-s doped metal sulfide semiconductor as a highly efficient photocatalyst for chromium reduction under light irradiation.