Synthesis of NiCo-LDH and Its Catalytic Performance for Tetracycline Degradation in Aqueous Solution

NiCo-LDH catalysts with different Ni/Co molar ratios were synthesized via the hydrothermal method. The crystal structure, microstructure, and pore characteristics of the samples were characterized by x-ray diffraction, scanning electron microscopy and N 2 adsorption-desorption techniques. Taking tetracycline as the target pollutant, the performance and influencing factors of TC degradation by peroxymonosulfate catalyzed by NiCo-LDH were systematically investigated, and the degradation mechanism was revealed by free radical quenching experiments. The results showed that when the Ni:Co molar ratio was 1:2, NiCo-LDH exhibited a typical layered structure with a specific surface area of 136 m 2 g −1 and the optimal catalytic activity. Under the conditions of 25°C, pH = 7.02, and PMS dosage of 0.06 mmol, TC was completely degraded within 15 min. The catalytic system showed high degradation efficiency in the pH range of 5–9, and the synergistic effect of four free radicals (SO 4 · − ,·OH, 1 O 2, and O 2 · − ) was the main reason for TC degradation. The granular NiCo-LDH catalyst prepared by inverse suspension polymerization had a catalytic degradation rate of 88.3%, solving the recovery problem of powder catalysts. As a PMS activation catalyst, NiCo-LDH has a good application prospect in antibiotic wastewater treatment. Graphical Optimized NiCo-LDH powder efficiently activates peroxymonosulfate via reversible Ni 2 + /Ni 3 + and Co 2 + /Co 3 + redox cycles. Four reactive oxygen species synergistically achieve over 90% tetracycline removal within 15 min across a broad pH range, and porous polymer-immobilized microspheres enable convenient recovery for practical antibiotic wastewater treatment.