Enriched Surface Oxygen Vacancies of Fe 2 (MoO 4 ) 3 Catalysts for a PDS-Activated photoFenton System.

The environmentally benign Fe 2 (MoO 4 ) 3 plays a crucial role in the transformation of organic contaminants, either through catalytically decomposing oxidants or through directly oxidizing the target pollutants. Because of their dual roles and the complex surface chemical reactions, the mechanism involved in Fe 2 (MoO 4 ) 3 -catalyzed PDS activation processes remains obscure. In this study, Fe 2 (MoO 4 ) 3 was prepared via the hydrothermal and calcine method, and photoFenton degradation of methyl orange (MO) was used to evaluate the catalytic performance of Fe 2 (MoO 4 ) 3 . Fe 2 (MoO 4 ) 3 catalysts with abundant surface oxygen vacancies were used to construct a synergistic system involving a photocatalyst and PDS activation. The oxygen vacancies and Fe 2+ /Fe 3+ shuttle played key roles in the novel pathways for generation of •O 2 - , h + , and 1 O 2 in the UV-Vis + PDS + FMO-6 photoFenton system. This study advances the fundamental understanding of the underlying mechanism involved in the transition metal oxide-catalyzed PDS activation processes.