Switch PMS activation pathway from free radical to non-radical by introducing hexagonal boron nitride in supported CoFe₂O₄: The role of lattice oxygen and PMS adsorption

Three supported spinel cobalt ferrite (CoFe₂O₄) catalysts were synthesized and applied in peroxymonosulfate (PMS) activation for antibiotics degradation. The introduction of boron nitrogen as the support accelerated the transformation from classic free radical oxidation process (·OH and SO₄^·−) to non- radical oxidation process (¹O₂) compared with CoFe₂O₄/bulk carbon nitride (BCN), CoFe₂O₄/activated carbon (AC), CoFe₂O₄ and boron nitrogen (BN). Unlike CoFe₂O₄/BCN and CoFe₂O₄/AC, the resulting CoFe₂O₄/BN with strong metal oxide-support interaction improved the content of lattice oxygen and PMS adsorption performance, accelerating the generation of ¹O₂ and the decrease in energy barrier of PMS activation. The kinetic constant of 5-CoFe₂O₄/BN was 2.66, 2.0 and 3.7 times higher than that of pure CoFe₂O₄, 5-CoFe₂O₄/BCN and 5-CoFe₂O₄/AC, respectively.