Metal-based materials are widely regarded as promising catalysts for activating peroxymonosulfate (PMS) to remove refractory organic contaminants with high efficiency. In our study, Ni-Fe layered double hydroxide (LDH)-biochar (BC) composite-induced PMS-based advanced oxidation process (AOP) was utilized to elucidate the degradation of tetracycline hydrochloride (TCH). In Ni-Fe LDH-BC/PMS system, more than 99% TCH (45 μM) could be removed effectively at low doses of oxidant (PMS, 0.10 mM) and catalyst (Ni-Fe LDH-BC, 0.10 g/L) addition within 80 min. Besides, the Ni-Fe LDH-BC/PMS system showed high resistance to some inorganic anions, and the Ni-Fe LDH-BC composite possessed excellent reusability in the degradation of TCH (>99% in four cyclic experiments). The reaction mechanisms were investigated via electron paramagnetic resonance detection, chemical quenching tests, probe experiments, and electrochemical measurements. These results indicated that the electron-shuttle mechanism played the dominant role in the removal of TCH. It is worth noting that determination of PMS concentration can reflect the reliability of quenching experiments. In the Ni-Fe LDH-BC composite, BC could not only improve the dispersion of Ni-Fe LDH, but also increase the conductivity of Ni-Fe LDH. Overall, a successful modification strategy was proposed in our study to improve the catalytic property of Ni-Fe LDH, and reaction mechanisms of TCH degradation were discussed deeply and comprehensively.

金属基材料被广泛认为是激活过一硫酸盐（PMS）以高效去除难降解有机污染物的有前途的催化剂。在我们的研究中，利用镍铁层状双氢氧化物（LDH）-生物炭（BC）复合物诱导的基于PMS的高级氧化工艺（AOP）来阐明盐酸四环素（TCH）的降解。在Ni-Fe LDH-BC/PMS体系中，低剂量的氧化剂（PMS，0.10 mM）和催化剂（Ni-Fe LDH-BC，0.10 g/L）即可有效去除99%以上的TCH（45 μM）。 80分钟内添加 此外，Ni-Fe LDH-BC/PMS体系对某些无机阴离子表现出较高的耐受性，并且Ni-Fe LDH-BC复合材料在TCH降解中具有优异的可重复使用性（四次循环实验中>99%）。通过电子顺磁共振检测、化学猝灭测试、探针实验和电化学测量研究了反应机理。这些结果表明电子穿梭机制在TCH的去除中起主导作用。值得注意的是，PMS浓度的测定可以反映猝灭实验的可靠性。在Ni-Fe LDH-BC复合材料中，BC不仅可以改善Ni-Fe LDH的分散性，还可以提高Ni-Fe LDH的电导率。总的来说，我们的研究提出了一种成功的修饰策略来提高Ni-Fe LDH的催化性能，并对TCH降解的反应机制进行了深入而全面的讨论。