Synthesis of cake-like Ti-Bi bimetallic MOFs-derived OV-rich A-TiO2/β-Bi2O3 heterojunctions for photodegradation of ciprofloxacin

Abstract

The cake-like Ti-Bi bimetallic MOFs and MOFs-derived oxygen vacancy-rich (OV-rich) A-TiO2/β-Bi2O3 heterojunctions were synthesized by solvothermal and high-temperature calcination techniques and applied to the degradation of ciprofloxacin (CIP). The cake-like morphology of the inherited parent MOFs allowed the A-TiO2/β-Bi2O3 heterojunctions to expose more active sites, which facilitated the enrichment of CIP. Under visible light, the synergistic effect of abundant oxygen vacancies (OV) and heterojunction results in stronger photo-responsiveness, higher photogenerated carrier separation efficiency and low recombination rate of A-TiO2/β-Bi2O3. The results of EPR as well as photodegradation CIP experiments show that heterojunction A-TiO2/β-Bi2O3 has more abundant OV and superior photocatalytic activity compared with monometallic MOFs derivatives (A/R-TiO2 and α-Bi2O3). Theoretical calculations reveal that OV can modulate the electronic and energy band structure of the material surface. In this study, new bimetallic MOFs were prepared, and OV-rich heterojunctions derived from MOFs were developed for the efficient degradation of pollutants under visible light.