FeN4-doped carbon nanotubes derived from metal organic frameworks for effective degradation of organic dyes by peroxymonosulfate: Impacts of FeN4 spin states

Development of low-cost, high-performance catalysts for the effective degradation organic dyes is both fundamental and technological significance environmental remediation. Herein, FeN4-doped carbon nanotubes exhibit a remarkable catalytic activity towards acid orange 7 (AO7) in presence peroxymonosulfate (PMS). This accounted by abundant well-dispersed FeN4 sites appropriate adsorption energy. Radical quenching experiments electron paramagnetic resonance measurements suggest that singlet oxygen main reactive species. 57Fe Mossbauer spectroscopy show moieties contain multiple spin states, conjunction with density functional theory calculations, confirm low/medium state serves as key PMS activation hence AO7 degradation. Results from this study highlight critical role states generation pollutants.