Bimetallic-nitrogen-carbon aerogel Co/Ni–N-C derived from 2D ordered nanosheet arrays activate PMS-AOPs for effective antibiotic removal: performance, mechanism, and toxicity

In recent years, peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) have garnered increasing attention for their efficacy in eliminating persistent organic pollutants. Metal-nitrogen-carbon (M–N-C) materials are frequently employed as efficient catalysts for the activation of PMS, leading to the effective production of various reactive species. In this study, a novel 3D porous cobalt/nickel bimetallic-nitrogen-carbon aerogel (Co/Ni–N-C) with well-dispersed CoNi-nanosheets that enhance electron transfer and provide a large active surface area was prepared through an in situ growth and a straightforward pyrolysis procedure of 2D cobalt/nickel metal–organic framework (CoNi-MOF) which was contained by a bamboo cellulose aerogel as a precursor. Rapid tetracycline (TC) removal (efficiency of 99.83% and mineralization rate of 69.8%) was achieved via PMS activation, facilitated by a synergistic enhancement effect of well-dispersion CoNi-nanosheet array. The evenly dispersed Co/Ni–N active sites and high Co:Ni ratio (P_Co:_Ni = 0.21) producing multiple reactive oxygen species (ROS) were essential in accelerating removal of contaminant. The toxicity assessment results of the intermediates further confirmed that the catalytic degradation in the Co/Ni–N-C-800/PMS system reduced the ecological toxicity of TC through dehydroxylation, demethylation, ring-opening, and deamidation. Furthermore, the Co/Ni–N-C-800/PMS system demonstrated exceptional degradation efficiency for various aromatic compounds with diverse substituents and showed good cyclic stability. These findings offer insights into the development of highly effective bimetallic-nitrogen-carbon catalytic materials.

Graphical Abstract