Regulated Zinc-Based Organic Frameworks by Linker Functionalization for Multifunctional Photocatalysis and Photoelectrocatalysis.

Reactive oxygen species (ROS) play a critical role in driving photocatalytic reactions. The predominant type of ROS generated determines the efficiency and feasibility of diverse photocatalytic transformations. However, limited research has focused on the targeted generation of ROS tailored for diverse catalytic transformations. Herein, four pillar-layered zinc-based organic frameworks (Zn-MOFs) were synthesized via linker engineering. By functionalizing the organic linkers, the prioritization of the generation of different ROS by these frameworks was modulated, thereby enhancing their efficiency in targeting photocatalytic transformations. Compared to the original Zn-MOF, the functionalized linker-constructed MOFs exhibit significantly enhanced charge carrier mobility. Notably, the Zn-MOF functionalized with electron-withdrawing fluorine groups (HIAM-3001F) demonstrated the highest catalytic efficiency in the superoxide anion-dominated photocatalytic cyclization synthesis of tetrahydroquinoline derivatives, achieving a near-unity conversion and a yield of 88.5% for gram-scale target compounds. In contrast, HIAM-3001Me, functionalized with electron-donating methyl groups, exhibited superior performance in the hydroxyl radical-driven photoelectrocatalytic (PEC) degradation of 4-fluorophenol, achieving almost complete degradation within 2 h. This work emphasizes the crucial role of rational linker design in regulating the photocatalytic performance of MOFs, and provides guidance for the construction of multifunctional and efficient MOF photocatalysts with targeted regulation of photocatalytic properties.