A nanosheet-like BiPO4/Bi2O2CO3 heterostructured photocatalyst with enhanced photocatalytic activity

Abstract

A nanosheet-like BiPO₄/Bi₂O₂CO₃ heterostructured photocatalyst with different amounts of BiPO₄ contents was successfully synthesized by the hydrothermal method. The photocatalytic activities of the BiPO₄/Bi₂O₂CO₃ composite, pure Bi₂O₂CO₃ and BiPO₄ were evaluated by the photodegradation of rhodamine B (RhB) solution under UV light irradiation. The results demonstrated that all of the as-prepared BiPO₄/Bi₂O₂CO₃ composites exhibited much higher photocatalytic activity than individual Bi₂O₂CO₃ and BiPO₄. Among the composites, the 3% BiPO₄/Bi₂O₂CO₃ showed the highest photocatalytic activity and the photodegradation efficiency of RhB could reach 92.6% within 40 min, which was about 1.7 and 2.3 times higher than that of pure Bi₂O₂CO₃ and BiPO₄, respectively. Simultaneously, the photostability and recyclability of 3% BiPO₄/Bi₂O₂CO₃ were also investigated by four cycling runs for the photodegradation of RhB and the composite exhibited no significant loss of photocatalytic performance, confirming its long-time reusability. The enhanced photocatalytic activity of the BiPO₄/Bi₂O₂CO₃ composite could be attributed to the formation of a suitable heterojunction structure, which facilitated interfacial charge transfer and improved the separation efficiency of photogenerated electron–hole pairs. Moreover, active species trapping experiments demonstrated that the holes (h⁺) played key roles in RhB degradation. On the basis of experimental and theoretical calculation results, a possible reaction mechanism of the enhanced photocatalytic activity was proposed.