Highly Stable π‑Extended Viologen Functionalized Hybrid Lead Halides for Near Infrared‐Driven CO <sub>2</sub> ‐to‐C <sub>2</sub> H <sub>4</sub> Photoconversion
Chen Sun, Jinlin Yin, Honghan Fei
Abstract
Abstract Hybrid lead halides show great potential for CO 2 photoreduction owing to their structural tunability and excellent photophysical properties. However, their intrinsic instability and the suppressed efficiency of C–C coupling under near‐infrared (NIR) irradiation highlight the significant challenges of developing a stable, single‐component photocatalyst with efficient NIR utilization. Herein, we incorporate π‐extended viologen units into two hybrid lead halides via coordination‐driven assembly, forming intrinsic donor–acceptor (D–A) configurations. Dimensional modulation from 1D to 2D extends the NIR absorption to 965 nm, affording a narrow bandgap of 1.28 eV. The inherent D–A system, combined with excellent carrier mobility of lead halides, promotes efficient electron migration from the lead halide components to the viologen moieties, generating stable N‐radical species. The resultant single‐component photocatalyst achieves selective CO 2 ‐to‐C 2 H 4 conversion with high apparent quantum yields (AQYs) of 0.81% at 700(±15) nm and 0.38% at 800(±15) nm, exceeding typical NIR‐responsive photocatalysts that typically generate C 1 products. Mechanistic investigations reveal that the accumulated carriers enhance *CO intermediate formation on adjacent N radical sites with close proximity (∼4.7 Å), promoting *CO–CO coupling. This work presents an effective strategy for utilizing low‐energy NIR light and drive CO 2 conversion to high‐value C 2 hydrocarbons, advancing the design of high‐performance metal halide photocatalysts.