MOF-derived Fe2O3@C-coupled Bi2MoO6 heterojunctions for highly efficient Photo-Fenton degradation of tetracycline

Hematite (α-Fe2O3) as a potential Fenton/Photo-Fenton reactant for advanced oxidation of wastewater. However, considering some deficiencies in the application of hematite alone (α-Fe2O3) in Photo-Fenton catalysis, we elaborately designed MOF-derived Fe2O3@C-coupled Bi2MoO6 heterojunctions (FO@C/BMO) to construct a Photo-Fenton system for the decomposition of tetracycline (TC). The successful synthesis of heterojunction materials was demonstrated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoelectron spectroscopy (XPS). The optoelectronic properties of the heterojunctions were characterized by UV–visible diffuse reflectance (UV–Vis), fluorescence spectroscopy (PL), instantaneous photocurrent response (I-T), and electrochemical impedance spectroscopy (EIS).The experimental results showed that FO@C/BMO eliminated 93.2% of tetracycline (TC) at 50 min. Comparative experiments revealed that the rate constants of the photo-Fenton reaction were much larger than those of the Fenton reaction and the photocatalytic reaction, due to the synergistic effect of Fenton oxidation and photocatalysis, where the photogenerated electrons generated by the photocatalytic process promoted the Fe3+/Fe2+ cycle, and thus the catalyst was able to maintain a good reaction performance.