Surface oxygen vacancies prompted the formation of hydrated hydroxyl groups on ZnOx in enhancing interfacial catalytic ozonation.

Herein, a highly dispersed catalyst (ZnO x -500) was synthesized for heterogeneous catalytic ozonation (HCO), which had a simple ZnO crystal phase but riched in oxygen vacancies (OVs). The O 3 /ZnO x -500 system exhibited both superior catalytic activity and stability after several cycles, providing a promising strategy for atrazine (ATZ) removal. The strong inhibition of phosphoric acid validated the dominant role of the hydroxyl group (−OH) from water molecule (H 2 O) dissociation on the zinc site near OVs. Density functional theory calculation further revealed that OVs on (100) and (101) planes could make more zinc sites exposed and facilitate the formation of hydrated −OH, which was easier to approach O 3 for its decomposition to generate hydroxyl radical (•OH). This work revealed the intrinsic relationship between OVs and hydrated −OH in an aqueous solution, providing new insight into the solid-liquid interface mechanism of HCO. [Display omitted] • ZnO x -500 riched in oxygen vacancies was synthesized via a one-step method. • Oxygen vacancies promoted the formation of surface –OH by dissociating water molecules. • The formed surface −OH effectively attributed to •OH production. • OH played a crucial role in O 3 /ZnO x -500 for ATZ degradation. [ABSTRACT FROM AUTHOR]