Synthesis of Ta3N5/Bi2MoO6 core–shell fiber-shaped heterojunctions as efficient and easily recyclable photocatalysts

Abstract

Developing efficient and easily recyclable photocatalysts has drawn much attention. Herein, we report the design and synthesis of Ta₃N₅/Bi₂MoO₆ core–shell fiber-shaped heterojunctions as a kind of efficient and easily recyclable photocatalyst. Ta₃N₅ nanofibers have been prepared by an electrospinning–calcination–nitridation method, and then in situ growth of Bi₂MoO₆ on their surfaces is realized by a solvothermal method. The resulting Ta₃N₅/Bi₂MoO₆ heterojunctions are composed of porous Ta₃N₅ nanofibers (diameter: ∼200 nm) whose surfaces are decorated with Bi₂MoO₆ nanosheets (length: 100–200 nm; thickness: ∼15 nm). They exhibit remarkably enhanced photocatalytic activities for the degradation of rhodamine B (RhB) and para-chlorophenol (4-CP) under visible light, compared with pure Bi₂MoO₆ or Ta₃N₅. In particular, the heterojunction with a Ta₃N₅/Bi₂MoO₆ molar ratio of 1/1 achieves the highest photodegradation efficiency of RhB (99.5%), which is about 1.85 times that (53.7%) of Bi₂MoO₆ and 1.66 times that (60.1%) of the mechanical mixture (49.8 wt% Bi₂MoO₆ + 50.2 wt% Ta₃N₅). The superior photocatalytic properties can be attributed to the efficient separation of photo-induced electron–hole pairs and the high BET surface area. The dominant active species are determined to be superoxide and the photogenerated holes. More importantly, the Ta₃N₅/Bi₂MoO₆ heterojunction can be easily recycled by simple sedimentation while maintaining good stability. This work offers more valuable insights into the design of efficient and easily recyclable photocatalysts for environmental remediation.