Self-assembly synthesis of S-scheme g-C3N4/Bi8(CrO4)O11 for photocatalytic degradation of norfloxacin and bisphenol A

To realize the high-efficiency photodegradation of antibiotics, a novel S-scheme heterojunction photocatalyst g-C3N4/Bi8(CrO4)O11 was proposed and successfully prepared in this work. The 10% g-C3N4/Bi8(CrO4)O11 heterojunction exhibits the highest degradation rate of norfloxacin (NOR) and bisphenol A (BPA). The degradation rate of NOR on 10% g-C3N4/Bi8(CrO4)O11 is about 1.38 and 2.33 times higher than that of pure Bi8(CrO4)O11 and g-C3N4, respectively. Further, the degradation rate of BPA over 10% g-C3N4/Bi8(CrO4)O11 heterojunction is bout 1.35 and 9.11 times higher than that of pure Bi8(CrO4)O11 and g-C3N4, respectively. The formation of S-scheme heterojunction facilitates the separation of photogenerated electron-hole pairs and reduces the recombination of charge carriers, which was confirmed by photocurrent, electrochemical impedance spectroscopy, steady-state and time-resolved transient photoluminescence spectrum, etc. The in-situ X-ray photoelectron spectroscopy, radical trapping experiments and electron paramagnetic resonance results demonstrate that the charge transfer is in accord with S-scheme mechanism.