Enhanced photocatalytic ability and easy retrievable photocatalysts of Bi2WO6 quantum dots decorated magnetic carbon nano-onions

Bi2WO6 quantum dots (DQs) decorated magnetic carbon nano-onions (MCNOs) were prepared via a hydrothermal method. The Bi2WO6 QDs were measured to be about 2-10 nm and anchored on the surface of MCNOs uniformly. The great paramagnetic characteristic of composites was demonstrated by hysteresis loops measurement, and this feature made it easy to recover the photocatalysts from reaction system. In addition, rhodamine B (RhB), methylene blue (MB), and phenol were used to examine the photocatalytic performance of composites under visible light irradiation, and the reasons for the enhanced photocatalytic performance of composites compared with pure Bi2WO6 QDs were discussed by active trapping measurement and photocurrent response experiment. Results showed that MCNOs acted not only a magnetic supporter to prevent Bi2WO6 QDs from aggregation but also an electronic transmitter to decrease the recombination of photogenerated electron-hole (e(-)-h(+)). The easy-retrievable photocatalysts with high photocatalytic performance will hold a great promise to be widely used in the field of water purification. (C) 2020 Elsevier B.V. All rights reserved.