Unraveling the mechanistic dominance of superoxide over singlet oxygen in ZnTi-LDH photocatalysis

Environmental discharge of antibiotics and dyes poses serious threats to human survival and development. In this study, sheet‐like ZnTi‐layered double hydroxide (ZnTi‐LDH) photocatalysts were rapidly synthesized via hydrothermal method at varying reaction temperatures. With increasing hydrothermal temperature, the formation of ZnTi‐LDH became more pronounced, and its photocatalytic performance was assessed using tetracycline hydrochloride (TCH) and Congo red (CR) as model contaminants. The photocatalytic performance of ZnTi-LDH prepared at 210 °C after 60 min of light exposure was optimal, with degradation degree of TCH and CR reaching 84.20 % and 62.75 %, respectively. Similarly, the corresponding first-order reaction rate constants are also the highest, at 0.021 min −1 and 0.010 min −1 , respectively. Mott–Schottky analysis, optical property analysis and electrochemical property analysis combined were conducted to elucidate the photodegradation mechanisms of TCH and CR on ZnTi‐LDH. Reactive‐species trapping experiments confirmed that photogenerated electrons primarily generate superoxide radicals through electron transfer rather than forming singlet oxygen via energy transfer.