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

Abstract

Ta ₃N ₅/Bi ₂MoO ₆ core–shell fiber-shaped heterojunctions have been prepared, and they can be used as efficient and easily recyclable photocatalysts for environmental remediation.

Abstract

Developing efficient and easily recyclable photocatalysts has drawn much attention. Herein, we report the design and synthesis of Ta ₃N ₅/Bi ₂MoO ₆ core–shell fiber-shaped heterojunctions as a kind of efficient and easily recyclable photocatalyst. Ta ₃N ₅ nanofibers have been prepared by an electrospinning–calcination–nitridation method, and then in situ growth of Bi ₂MoO ₆ on their surfaces is realized by a solvothermal method. The resulting Ta ₃N ₅/Bi ₂MoO ₆ heterojunctions are composed of porous Ta ₃N ₅ nanofibers (diameter: ∼200 nm) whose surfaces are decorated with Bi ₂MoO ₆ 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 Bi ₂MoO ₆ or Ta ₃N ₅. In particular, the heterojunction with a Ta ₃N ₅/Bi ₂MoO ₆ molar ratio of 1/1 achieves the highest photodegradation efficiency of RhB (99.5%), which is about 1.85 times that (53.7%) of Bi ₂MoO ₆ and 1.66 times that (60.1%) of the mechanical mixture (49.8 wt% Bi ₂MoO ₆ + 50.2 wt% Ta ₃N ₅). 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 Ta ₃N ₅/Bi ₂MoO ₆ 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.