Study on the photocatalytic properties of the ternary ZnO/MgAl-LDH/FeOOH composite photocatalyst with a Type-II and S-scheme linked carrier migration mechanism in degrading TC solution

Abstract

The synthesis of high-performance photocatalysts represents a pivotal aspect of research into photocatalytic degradation technology. In order to address this need, a novel ZnO/MgAl-LDH/FeOOH ternary composite photocatalyst has been synthesized via a multi-step process involving the hydrothermal, calcination and ultrasonic-assisted wet impregnation methods. The ternary composite photocatalyst was observed to demonstrate effective separation of photogenerated carriers in photocatalysis, following a Type-II and S-scheme linked carrier migration mechanism. An examination of the photocatalytic characteristics of the composite photocatalyst in the degradation of a tetracycline (TC) solution revealed that the reduction of •O_2^- radicals and the oxidation of •OH radicals resulted in the effective degradation of the TC solution. The degradation efficiency of the TC solution under the photocatalysis of the ternary composite photocatalyst was observed to be 1.54, 1.11 and 3.15 times that of the single-component samples of ZnO, MgAl-LDH and FeOOH, respectively, in 30 min. Moreover, the degradation pathway of TC molecules under the photocatalysis of the composite has been elucidated. The research findings provide a foundation for further investigation into this composite photocatalyst.