Mechanism and efficiency of photocatalytic triclosan degradation by TiO2/BiFeO3 nanomaterials


 Hierarchical porous TiO2 photocatalytic nanomaterials were fabricated by impregnation and calcination using a peanut shell biotemplate, and TiO2/BiFeO3 composite nanomaterials with different doping amounts were fabricated using hydrothermal synthesis. The micromorphology, structure, element composition and valence state of the photocatalyst were analyzed using a series of characterization methods, including XRD (X-ray diffraction), SEM (scanning electron microscope), TEM (transmission electron microscope), BET (BET surface area), XPS (X-ray photoelectron spectroscopy), UV-vis (UV-visible diffuse reflectance), PL (fluorescence spectroscopy) and other technological means. Finally, the degradation mechanism and efficiency of BiFeO3 composite photocatalyst on the target pollutant triclosan were analyzed using a xenon lamp to simulate sunlight. The results showed that TiO2/BiFeO3 catalyst fabricated using a peanut shell biotemplate has a specific surface area of 153.64 m2/g, a band gap of 1.92 eV, and forms heterostructures. The optimum doping amount of TiO2/BiFeO3 catalyst was 1 mol/mol, and the degradation rate was 81.2%. The main active substances degraded were ·O2−and ·OH. The degradation process measured is consistent with the pseudo-first-order kinetic model.