Highly Stable π‑Extended Viologen Functionalized Hybrid Lead Halides for Near Infrared-Driven CO₂-to-C₂H₄...

Hybrid lead halides show great potential for CO₂ 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 CO₂-to-C₂H₄ 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 C₁ 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 CO₂ conversion to high-value C₂ hydrocarbons, advancing the design of high-performance metal halide photocatalysts.