A novel Z-scheme ZnO/N-Cu-MOF photocatalyst for efficient inactivation of Hematodinium dinospores

The parasitic dinoflagellate in Hematodinium genus causes significant economic losses to fishery and aquaculture of multiple valuable marine crustaceans. It is practically needed to develop an effective and environmentally compatible method to control the Hematodinium epidemics in mariculture. In the present study, a novel Z-scheme composite photocatalyst was synthesized successfully using Zinc oxide (ZnO) and Copper Metal-Organic Framework (Cu-MOF), The N-Cu-MOF photocatalyst showed superior charge carrier separation efficiency compared to Cu-MOF, and exhibited significantly improved visible-light absorption in contrast to the activation of ZnO only under UV light. The ZnO/N-Cu-MOF photocatalyst demonstrated excellent inactivation of Hematodinium perezi microspores, with half maximal inhibitory concentration (IC 50 ) values of 3.12 mg/L at 1 h and 1.01 mg/L at 2 h. The inactivation effects involved the generation of large amounts of intracellular reactive oxygen species (ROS), which induced oxidative stress and disrupted the membrane and flagella structural integrity of the dinospores, ultimately leading to cell necrosis induced by oxidative damage. The present study provided a new insight and approach for seawater treatment of mariculture facilities, thereby to prevent and control spreading of Hematodinium epidemics in commercially valuable crustaceans.