Co-Embedded N-Doped Carbon Composites Derived from CoZn-ZIFs for Peroxymonosulfate Activation Toward Efficient Tetracycline Degradation

Zeolite imidazolate frameworks (ZIFs)-derived carbon materials have garnered widespread attention as peroxymonosulfate (PMS) activators in removing antibiotics because of their excellent catalytic performance. However, most carbon materials derived from ZIFs exhibit limited efficacy in treating high-concentration (>10 ppm) antibiotic wastewater, and their synthesis methods are environmentally unfriendly. Herein, we develop a simple and environmentally friendly preparation method to synthesize a new type of nitrogen-doped carbon-supported carbon nanotubes coated with cobalt nanoparticle (Co-CNTs@NC) composites via high-temperature calcination of cobalt–zinc bimetallic ZIFs. The material characterization results confirm the successful preparation of Co-CNTs@NC composites featuring a high specific surface area (512.13 m2/g) and a Co content of 5.38 wt%. Across an initial pH range of 3.24–9.00, the Co-CNTs@NC/PMS catalytic system achieved over 84.17% degradation of 20 mg/L tetracycline hydrochloride within 90 min, demonstrating its favorable pH tolerance. The singlet oxygen-dominated degradation mechanism was confirmed by quenching experiments and electron paramagnetic resonance characterization. This work can provide technical guidance and reference significance for the preparation of metal–carbon materials derived from ZIFs with excellent efficiency of removal of high-concentration antibiotics.