Spatial self-confinement of heterogeneous metallic CoX (X = Cu, Ni, Fe) within laminated porous carbon assemblies to efficiently activate peroxymonosulfate for tetracycline destruction

Abstract

Sustainable and universal fabrication of carbon-loaded non-precious bimetallic nanocatalysts with tuned catalytic surface sites is crucially important but challengeable toward peroxymonosulfate(PMS)-motivated antibiotic degradation. We propose herein a universal, easily removable and sustainable salt template-mediated spatial self-confinement strategy to fabricate bimetallic nanoparticles deposited onto lamellar porous carbon assemblies for PMS-assisted tetracycline hydrochloride (TCH) destruction. Among CoX@C-600 (X = Cu, Ni, Fe) samples, CoCu@C-600 has the highest catalytic performance with a degradation efficiency of 98.6% and a rate constant of 0.3174 min−1 for TCH degradation via PMS motivation. The synergy between the heterogeneous metallic Co and Cu nanoparticles, unique tertiary pore structure and copious surface-exposed active sites are responsible for the high performance of CoCu@C-600. The magnetically recoverable CoCu@C-600 shows a good separation property and can be reused for five consecutive runs. Experimental and characterization results affirm the radical/non-radical (major active species of SO4•− and 1O2) and direct electron transfer mechanism. The degradation pathways and toxicity evaluation with the CoCu@C-600/PMS system are unveiled. The rational architecture design and catalytic site regulation are inspirable for universal syntheses of efficient catalysts for antibiotic degradation.