Self-assembly of 3D hierarchical halloysite-nanotube/CoAl-LDH-nanosheet hybrid microspheres for high-performance degradation of norfloxacin

In this paper, 3D hierarchical CoAl-LDH microsphere hybrid catalysts were fabricated via a facile two-step procedure. The results demonstrated that halloysite (Hal)-nanotube and CoAl-LDH-nanosheet were reconstructed into 3D hierarchical hybrid microspheres. In addition to providing Al element, the Hal also maintained a high specific surface area of the microspheres and exhibited excellent adsorption properties. The novel catalysts could activate peroxymonosulfate (PMS) to generate HO• and SO4•– free radicals, resulting in a 97% degradation rate of norfloxacin (NOR) at a concentration of 20 mg/L. This study provides insights into using nano-clay precursors for constructing CoAl-LDH hybrid catalysts to purify antibiotic contaminants from aqueous environments.