Adsorption and photothermal catalysis enhance degradation of tetracycline hydrochloride over porous nanorod-shaped zinc ferrite

Extensive use and environmental persistence of tetracycline hydrochloride (TC•HCl) pose significant threats to both ecological environment and human health. It is crucial to explore the efficient degradation method to realize sustainable development. This work proposes a photothermal catalysis (PTC) strategy for the degradation TC•HCl to improve its degradation efficiency than photocatalysis (PC) and thermal catalysis (TC). Porous nanorod-shaped zinc ferrite (ZF) with ferrimagnetic behavior was prepared via a hydrothermal-calcination method. ZF calcined at 400 °C (ZF-400) possesses a typical mesoporous structure with a specific surface area (SSA) of 35.68 m 2 ⋅g −1 , which is 1.97 and 5.03 times higher than those of ZF calcined at 500 °C (ZF-500) and 600 °C (ZF-600), respectively, exhibiting the strong physical adsorption capacity for TC•HCl. Abundant Lewis acid sites on the ZF-400 are beneficial to the chemisorption of TC•HCl. The excellent adsorption capacity of ZF-400 for TC•HCl follows the pseudo-second-order kinetic model with the adsorption rate constant of 61.2 × 10 −3 g⋅mg −1 ⋅min −1 . The PTC degradation of TC•HCl over ZF-400 reaches 93.4 % within 120 min and follows the pseudo-first-order kinetic model with the degradation rate constant of 9.5 × 10 −3 min −1 , being 2.88 times and 1.98 times higher than those of PC and TC, severally. Radical quenching experiments confirm that •O 2− , h + , and •OH serve as the dominant active species in the PTC degradation of TC•HCl over ZF-400. Besides, the PTC degradation of TC•HCl remains above 83 % with no significant decrease in catalyst activity after six cycles.