Preparation and photocatalytic properties of FeVO₄/Cu₃(BTC)₂(H₂O)₃ heterojunction

The classic Cu-MOF material Cu₃(BTC)₂(H₂O)₃, which was also named HKUST-1, was prepared by electrochemical method using Cu flakes and 1, 3, 5-benzenetricarboxylic acid as the raw materials. Furthermore, the FeVO₄/HKUST-1 heterojunction composites were prepared by room temperature deposition using HKUST-1 as the base metal organic framework material (MOFs). The crystal structure, morphology, specific surface area and optical absorption properties were characterized by XRD, SEM, BET, UV-Vis DRS, etc. The results indicate that the formation of the heterojunction between FeVO₄ and HKUST-1 is beneficial for the generation and transfer of the photogenerated electron-hole pairs. The degradation performance of target dye pollutant rhodamine B (RhB) is significantly enhanced. After visible light irradiating for 120 min, the degradation efficiency to RhB can reach 93% in the heterojunction system, while only 12% and 5% can be observed in the system of FeVO₄ or HKUST-1, respectively. In addition, the composition ratio of the composite was also optimized. When the molar ratio of FeVO₄ to HKUST-1 is 1∶1, the as-prepared FeVO₄/HKUST-1 composite has the best photocatalytic performance. Furthermore, the stability was investigated. After 5 cycles, the degradation efficiency to RhB is still above 90%, indicating good stability of the FeVO₄/HKUST-1 composite.