Synthesis of Fluoride-Substituted Layered Perovskites ZnMoO₄ with an Enhanced Photocatalytic Activity

Oxyfluorides possess considerable attention for their multiple excellent properties, but the conventional high-temperature solid-state syntheses have seen bottlenecks in the synthesis of new compounds. Herein, we report a novel layered oxyfluoride ZnMoO₄:F, which is prepared by a facile hydrothermal method using ZnF₂ as the fluoride source. The fluoride anions are successfully introduced into the oxygen sublattice, which is confirmed by a combined analysis using XRD, STEM, and TGA techniques. The as-synthesized ZnMoO₄:F has an absorption edge at around 550 nm, indicating a red shift of E_g to the visible region compared to the oxide counterpart. The layered oxyfluoride exhibits an enhanced photocatalytic active for hydrogen evolution under simulated sunlight (λ > 350 nm), and the activity of ZnMoO₄:F (651.9 μmol g^-1) was 2 times higher than that of ZnMoO₄ (309.7 μmol g^-1). Further electrochemical analysis has shown that the conduction band position plays a critical role in the high performances of ZnMoO₄:F. This work sheds new light on the future design and synthesis of novel fluoride-doped materials for photocatalysis applications.