Fig. 6. (A) Effect of the catalyst dosage on the MB removal efficiency; (B) effect of the catalyst dosage on the PMS decomposition; (C) effect of the PMS concentration on the MB removal efficiency. Experiment condition: MB = 0.2 mM, PMS = 2 mM (for A and B), Cu@Co-MOFs-3 = 0.1 g L⁻¹ (only for C), T = 25 °C.