Identify the Active Phase of Fe–CN Composites for Oxidation Removal of Rhodamine B with H2O2
AbstractFe-containing carbon nitrides (Fe–CN) prepared with various CN precursors, including dicyandiamide, melamine, guanidine hydrochloride and urea, were characterized by X-ray diffraction, thermal gravimetric analysis, N2physisorption, transmission electron microscopy, X-ray photoelectron spectroscopy and atomic emission spectrometer measurements, and used as catalysts to catalyze the rhodamine B oxidation with H2O2as oxidant. Characteristic results showed that Fe–CN exhibits different compositions, properties and catalytic performances if different CN precursors are used. The Fe–CN prepared from dicyandiamide contains mainly CN phase and certain amounts of surface Fe2O3phase, exhibits the best activity; while that prepared from urea contains mainly Fe2O3phase and few amounts of CN phase, exhibits the worst activity. Contrasting experiments conducted under light irradiation, with a supported Fe/CN_D catalyst, and that using a washed catalyst, suggested that the surface Fe2O3is the active site of the reaction.