Fe-Co/Fe3c Dual Active Sites Catalysts Supported on Nitrogen-Doped Graphitic Carbon for Ultrafast Degradation of High Concentration Rhodamine B

Abstract

A B S T R A C TIron-based catalysts have garnered great attention as alternatives for Fenton-like catalysts in the degradation of organic compounds. However, there is a demand for the synthesis of highly efficient iron-based catalysts that can solve the problems of iron dissolution and poor stability. Herein, nitrogen-doped graphitic carbon-supported Fe-Co/Fe3C dual active sites catalysts (Fe-Co/Fe3C-NC) are successfully prepared by ball milling method combined with subsequent high-temperature self-reduction. Fe-Co/Fe3C-NC shows high efficiency in the activation of peroxymonosulfate (PMS) for the ultrafast degradation of high concentration Rhodamine B (200 mg/L of RhB was completely degraded within 8 min and the degradation rate constant was as high as 0.5066 min−1), as well as high stability and good reproducibility, attributing to the synergistic mechanism between the dual active sites (Fe-Co and Fe3C) and the adsorption sites (Fe3C and pyrrolic-N). Chemical quenching experiments and electron paramagnetic resonance indicate that the prepared 0.5 wt%Fe-Co/Fe3C-NC exhibites outstanding activation for PMS by generating reactive oxygen radicals (SO4•− and 1O2 were dominant) and high-valent iron. This work shows useful insights into the synthesis of iron-based dual active sites catalysts, providing exciting chances for the highly efficient degradation of high concentration organic wastewater.

Keywords: Dual active sites catalyst, Peroxymonosulfate, Rhodamine B, Fenton-like catalysis, Ball milling