ZIF-8 derived ZnS/ZnO type-II heterojunction for efficient photocatalytic hydrogen peroxide production and norfloxacin degradation

Developing efficient heterojunction structures is of critical importance for boosting solar energy conversion in photocatalysis. Herein, a ZnS-ZnO heterojunction is fabricated via pyrolysis of zeolitic imidazolate framework-8 (ZIF-8) followed by in-situ sulfidation. Due to the formation of heterojunction, the separation efficiency of photogenerated carriers can be efficiently enhanced. As a result, the as-fabricated ZnS-ZnO heterojunction exhibited a H₂O₂ formation rate of 6.88 mmol g⁻¹ h⁻¹, which is 3.75-fold that of ZnO. The mechanism revealed that •OH and •O₂^- were active species involved in the photocatalytic H₂O₂ production process. Moreover, the as-prepared samples have been successfully applied to degrade norfloxacin and exhibited excellent removal efficiency. This work provides an efficient route to develop highly efficient photocatalyst based on metal-organic frameworks (MOF).