Construction of the rapid spatial charge migration core/shell heterostructure by ZnIn2S4 nanosheet-surface-loaded β-Bi2O3 for improved photooxidative performance

Abstract

The development of novel heterojunctions with optimized interface contact is essential for realizing the highly efficient solar conversion in photocatalysis. In this work, a series of β-Bi2O3/ZnIn2S4 (BO/ZIS) nanocomposite photocatalysts were firstly fabricated via a facile self-assembly process, in which a large number of ZnIn2S4 nanosheets were tightly loaded on β-Bi2O3 nanoparticles to form the unique core/shell heterostructure. The produced core/shell BO/ZIS hybrid heterojunction with larger contact areas could provide more high-speed charge transmission nanochannels for better spatial charge separation. The boosted charge carrier migration, extended spectral adsorption and increased surface areas were favorable for the enhancement of efficiency, thus contributing to the significantly improved tetracycline hydrochloride (TCH) photodegradation performance. In particular, the experimental results showed that the as-synthesized BO/ZIS-2 hybrid possessed the optimal degradation efficiency and its rate constant was about 1.84 and 2.49 times higher than those of bare β-Bi2O3 and Znln2S4, respectively. Furthermore, in accordance with the trapping analysis and HPLC–MS results, the predominant active specie acted during the reaction process and the degradation intermediate products of TCH were proposed. Finally, the possible reaction mechanism was put forward. This study verified that the construction of β-Bi2O3-based core/shell heterostructure was an effective strategy to improve its photocatalytic performance for its practical application.