Efficiency LaFeO3 and BiOI heterojunction for the enhanced photo-Fenton degradation of tetracycline hydrochloride

Long-term exposure to antibiotic may have adverse effects on human health including carcinogenesis or teratogenicity and the emergence of antibiotic resistance. Developing effective catalysts to degrade antibiotic pollution is an urgent demand. Herein, a heterogeneous photo-Fenton catalyst with enhanced tetracycline hydrochloride (TCH) degradation activity was developed by hydrothermally synthesizing lanthanum ferrite (LaFeO3) and bismuth iodide oxide (BiOI). LaFeO3/BiOI showed excellent repeatability and stability, and still maintained an extremely high degradation efficiency of 80.6% after three cycles. The LaFeO3/BiOI with 35 wt% LaFeO3 showed significantly enhanced degradation rate (93.6%) of TCH within 40 mins in the photo-Fenton system, compared with single photocatalytic degradation (41.2%) and Fenton degradation (83.1%). The parameter characterization and quenching experiments were carried out on the heterojunction. The possible degradation mechanisms of TCH were proposed. The results indicated that the existence of the built-in electric field in the heterojunction effectively promote the separation of photogenerated electrons and hole pairs. The photoelectrons activate H2O2 to generate OH and accelerate FeIII/FeII conversion. This work has developed a promising heterogeneous photo-Fenton catalysts, and stipulated some new insights for the removal of antibiotic pollutants.