Bimetallic FeCo nanoparticles embedded N-rich porous ZIF-derived carbon as highly active heterogeneous Fenton catalyst for degradation of tetracycline and organic dyes

Peroxymonosulfate (PMS) based advanced oxidation process (AOP) is used for the degradation of the organic molecules due to ease of reactive oxygen species (ROS) generation through activation. In this study, bimetallic FeCo nanoparticles (NPs) supported on N-doped porous carbons are prepared for the first time by in-situ co-precipitation of metal ions in ZIF-67 followed by carbonization. The prepared nanocomposite, denoted as Fe(x)Co@N-CZ-67, is used to activate PMS for Fenton-like degradations of tetracycline (TC) and dyes. The results reveal that about 96% of TC is degraded by Fe(0.4)Co@N-CZ-67 in 4 min. The catalyst can also degrade three organic dyes, namely methylene blue, neutral red and methyl orange with outstanding reaction rates of 1.75, 1.80 and 2.62 min⁻¹, respectively. The excellent catalytic activities of the catalysts can be ascribed to the synergistic effects between Fe and Co that enhance the electron transfer rate, uniform dispersion of NPs, presence of N in support, and generation of surface PMS complexes with high oxidation activity. Based on the quench experiments, SO₄^•–, •OH, O₂^•− and ¹O₂ are determined to be the ROS responsible for degradations organic molecules. Fe(x)Co@N-CZ-67 shows excellent catalytic activity over ten consecutive cycles with negligible metal leaching and remarkable structural stability.