Fabrication of one-dimensional Bi2O3–Bi14MoO24 heterojunction photocatalysts with high interface quality

Abstract

Novel, one-dimensional Bi₂O₃–Bi₁₄MoO₂₄ heterostructures with high interface quality were synthesized by high temperature calcination of Bi₂MoO₆–Bi(OHC₂O₄)·2H₂O precursors in air at 400 °C for 2 h. Bi₁₄MoO₂₄ grew on the Bi₂O₃ porous rods by crystallographic-oriented epitaxial growth, which increased the interface quality and then provided the smallest penetration barrier for electron–hole pair transfer between Bi₂O₃–Bi₁₄MoO₂₄ interfaces. The photocatalytic activity of the as-prepared products was evaluated by the degradation of methyl orange (MO) and phenol under solar/visible light irradiation. The results show that Bi₂O₃–Bi₁₄MoO₂₄ heterostructures display higher photocatalytic activity than that of the pure phase Bi₂O₃ and Bi₁₄MoO₂₄, and 100% phenol (10 mg L⁻¹) can be degraded in 80 min under visible light irradiation using the Bi₂O₃–Bi₁₄MoO₂₄ (DS-2) heterostructure as photocatalyst. This enhanced photocatalytic performance is ascribed to the synergistic effect of the suitable band alignment of the Bi₂O₃ and Bi₁₄MoO₂₄, high interface quality and one-dimensionally ordered nanostructure. Radical scavenger experiments proved that the photogenerated holes and ˙O₂⁻ play key roles during the photodegradation process. This work offers an effective route to the design and fabrication of the junction structures with high interface quality for photocatalytic applications.