Characterisation and application of bismuth ferrite - bismuth vanadate p-n heterojunction in the photoelectrocatalytic degradation of ciprofloxacin in water

Towards the photoelectrocatalytic degradation of ciprofloxacin, BFO/BVO heterojunction was constructed to improve the performance of the individual semiconductors. The enhanced performance of the heterojunction photoanode was attributed to increase in visible light harvesting, greater current mobility leading to higher current density, low charge transfer resistance, and low recombination rate of photogenerated electron and hole. The BFO, BVO and BFO/BVO photoanodes prepared were immobilized on fluorine doped tin oxide coated glass and characterised using x-ray diffractometry, scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), UV–vis diffusive reflectance spectroscopy, photocurrent measurement, ultra performance liquid chromatography- mass spectrometry (UPLC-MS). The percentage removal of ciprofloxacin using BFO, BVO and BFO/BVO photoanodes were 56%, 49% and 80.3% respectively. The current density of the heterojunction photoanode were markedly improved when compared to the individual performances of the photoanodes. Also, the BFO/BVO heterojunction photoanode showed stability after repeated usages. Data from UPLC-MS studies was used to propose the degradation pathway, products, and mechanism of the degradation process.