Highly active BiFeO3–g-C3N4 S-scheme heterojunction with improved antibiotic degradation under visible-light: revealing mechanism

The photocatalyst S-scheme BiFeO 3 –g-C 3 N 4 had been prepared by combining calcination and hydrothermal reaction. 10% BiFeO 3 –g-C 3 N 4 composite showed the greatest photocatalytic effect during tetracycline hydrochloride degradation (TC-HCl, 99.7% removal) within 100 min. Meantime, the photocatalytic efficacy was further confirmed by the removal efficiency of ciprofloxacin(CIP, 98.2% removal). The formation of S-scheme heterostructure and matching valence band and conduction band may be responsible for the improved photocatalytic efficiency of BiFeO 3 –g-C 3 N 4 . This leads to the rapid separation of photo-induced carriers, increased electronic transport capacity, and extended carrier lifetime. A study was done on the potential mechanism by employing chemical scavenger experiment revealing the paramount role of O 2 − . The composite could maintain photocatalytically stable even after five consecutive reaction cycles. The recovery efficiency of 10% BiFeO 3 –g-C 3 N 4 was high because of the magnetic property of BiFeO 3 , which was convenient for the recycling process. The produced photocatalyst has potential use in the field of photocatalysis, and this work provides a novel thought to raise the photocatalysts recovery efficiency during recycling.