Hydrothermal Synthesis of Novel MoS2/BiVO4 Hetero-Nanoflowers with Enhanced Photocatalytic Activity and a Mechanism Investigation

摘要

The flower-like MoS2/BiVO4 composite with heterojunction has been successfully fabricated by a two-step approach. A possible formation mechanism of this heterostructure was investigated. The calculated valence band offset (VBO) and conduction band offset (CBO) of MoS2/BiVO4 heterojunction showed that the VBO and CBO of MoS2/BiVO4 are 1.4 and 0.3 eV, respectively, implying the formation of well-defined staggered type II band alignment. The photo degradation of methylene blue (MB) was adopted to assess the photocatalytic ability of the pristine MoS2 and BiVO4 as well as MoS2/BiVO4 composites. It exhibited that the MoS2/BiVO4 composite structures performed much better than that of the pristine MoS2 and BiVO4, which was due to the staggered band alignment formed between the two structures. Besides, the corresponding mechanism of enhanced photocatalysis regarding the separation of the photogenerated electron-hole pairs for the heterojunction has also been investigated by the first-principles calculation.