ZIF-67-derived dispersed cobalt modified carbon nanotubes efficiently activate peroxomonosulfate for degradation of organic pollutants

By confining the metal nanoparticles within the carbon nanotubes, it is feasible to inhibit their aggregation and leaching while preserving their catalytic activity. In this study, a low cobalt leaching nanomaterial (Co@CNT-3) was developed using cobalt nanoparticle-modified carbon nanotubes (CNTs) derived from a porous morphology-controlled imidazolate molecular sieve framework (ZIF-67). This nanomaterial effectively activates PMS for the efficient degradation of organic pollutants. In this unique structure, exhibited excellent catalytic activity due to the synergistic interaction between ZIF-67-derived Co NPs and CNT-3. The removal of methylene blue (MB) reached >99 % within 20 min after the addition of peroxomonosulfate (PMS) and showed good catalytic activity in a wide pH range (3.0–11.0) and common anions (Cl− SO42− H2PO4− HCO3−) in the aqueous environment. The cobalt ion leaching rate of Co@CNT-3 in solution is only 0.01 mg/L. Through X-ray photoelectron spectroscopy (XPS), quenching and electron paramagnetic resonance (EPR) experiments, it was found that Co nanoparticles are the main catalytic active center, and a non-radical mechanism dominated by singlet oxygen (1O2) is proposed. This study provides a simple strategy for the synthesis of high-efficiency catalysts with low cobalt ion leaching.