N-doped graphitic carbon as a nanoporous MOF-derived nanoarchitecture for the efficient sonocatalytic degradation process

Here, a nanoporous N-doped graphitic carbon (NC) obtained via the pyrolysis of the zeolitic imidazolate framework-67 (ZIF-67) in the N₂ atmosphere and then etched with hydrofluoric acid (HF) to remove the cobalt particles. The carbonized imidazoles in the framework of the ZIF-67 converted to the formation of N-doped graphitic sheets. The N₂ adsorption-desorption isotherms verified an arise in the surface area after etching the carbonized ZIF-67 and removing the Co nanoparticles (384 m²/g). Then, the prepared nanoporous carbon (NC_ZIF-67) was employed as a catalyst under the ultrasonic (US) irradiation for the degradation of the methylene blue (MB) as a model thiazine-based dye. The effects of main operational parameters including the initial pH, MB concentration, catalyst dosage, and ultrasonic power on the coupled US/NC_ZIF-67 process were investigated. The addition of radical scavengers and enhancers revealed the main role of reactive oxygen species in the treatment process particularly hydroxyl radicals (^[rad]OH), in which their presence is confirmed by the photoluminescence (PL) spectra. The GC–MS method was performed for recognition of the seven detectable intermediates during the MB degradation.