Magnetic CoFe2O4@carbon yolk-shell nanoparticles as catalysts for the catalytic wet peroxide of paracetamol

This work focuses the use of carbon-coated magnetic cobalt ferrite nanoparticles as catalysts for catalytic wet peroxide oxidation (CWPO) of the emerging pollutant paracetamol. A magnetic core composed of CoFe2O4 is developed by a sol-gel method. The core is subsequently coated with a formaldehyde-resorcinol resin and TEOS, further carbonized at 600 ºC, and etched with NaOH to create a yolk-shell structure denoted as CoFe2O4@void@C. XRD, TEM, and FTIR analysis revealed that the uncoated core is composed by a CoFe2O4 cubic spinel structure with a crystallite size of 53 nm calculated using the W-H method, matching very well the average size observed by TEM (53.51  4.2 nm). Comparing the performances of CoFe2O4@void@C and of the bare CoFe2O4 in the CWPO of paracetamol, TOC removals of 46 and 58% are obtained respectively after 24 h of reaction. An empirical kinetic model based on second-order and autocatalytic expressions was developed to suitably describe the decomposition of H2O2 and the removal of paracetamol using CoFe2O4@void@C as catalyst.