In situ synthesis of Cu‐doped ZIF‐8 for efficient photocatalytic water splitting

Metal–organic frameworks (MOFs) reached a new level of research in photocatalysis by their virtue of tunable structure, modifiable pores, and a large surface area. Herein, we employed a simple metal ion exchange method to change ZIF‐8 from UV light to visible light absorption photocatalyst. In this work, Cu2+ ions are integrated within the ZIF‐8 framework to synthesize Cu‐doped ZIF‐8 photocatalysts and well characterized by using both the spectroscopic and electrochemical studies. The Cu@ZIF‐8 (CDZ‐20) photocatalyst shows enhanced light‐harvesting ability and remarkable hydrogen generation rate of 13.9 mmolg−1 h−1 with an apparent quantum efficiency (AQE) of 9.08%, which is 17 times higher than that of pristine ZIF‐8 photocatalyst. The higher photocurrent density of 34 μA/cm2 in CDZ‐20 further reinforced the superiority over the ZIF‐8 (1 μA/cm2). This work paves the way to engineer robust copper doped ZIFs photocatalyst under mild synthesis approach for efficient H2 evolution. Modulation of Cu‐doped ZIF‐8 band structures with improved visible‐light response enables enhanced photocatalytic hydrogen production.