Multistep Regulation of Ionic Liquids in Photocatalytic CO ₂ Reduction: From Capture, Preactivation, Carrier to Pathway Control

Ionic liquids (ILs) have attracted extensive attention in the field of photocatalytic CO 2 reduction due to their unique advantages in the synthesis of photocatalytic materials and the regulation of interfacial reactions. However, the key regulatory mechanisms of photogenerated carrier behavior and reaction pathways in dynamic photocatalytic reactions are not yet systematically summarized. This article focuses on the multiple roles of ILs in photocatalytic CO 2 reduction, focusing on their key contributions in enhancing CO 2 absorption, preactivation, regulating the behavior of photogenerated carriers, and steering the reaction pathway. At the same time, the synergistic potentials and application prospects of ILs in various coupled processes (such as photoelectrical, photothermal, and photoenzymatic) are discussed. Finally, this article outlines current research challenges and future development trends, aiming to provide a theoretical basis for an in‐depth understanding of the promotional effect of ILs, and a new idea for enabling more efficient and robust ionic liquid‐based photocatalytic reactions.