Near‐IR Light‐Driven Photocatalytic H 2 O 2 Production by Viologen‐Based Conjugated Microporous Polymer
Vinutha K. Venkatareddy, Abhijeet V. Kamble, Malakalapalli Rajeswara RaoABSTRACT
Near‐infrared (NIR) light‐driven photocatalytic H 2 O 2 generation represents a promising yet underexplored strategy for sustainable solar energy utilisation, offering key advantages such as low energy consumption, suppression of unwanted side reactions, and a superior penetration depth into the material. Herein, we report a vinylene‐linked diquat‐conjugated microporous polymer ( Bpy‐2D ), synthesised via acid‐catalysed Knoevenagel condensation of Bpy and TFB . The synergistic combination of the electron‐deficient viologen moiety and the vinylene linkage affords a narrow optical band gap of 1.16 eV and broad NIR absorption extending to ∼1400 nm. Interestingly, the polymer exhibited an exceptionally high electrical conductivity of 1.8 × 10 − 2 S m − 1 in the pristine state. Under NIR light irradiation using a red LED strip (wavelength range of 620–660 nm), an IR lamp (650 and 850 nm), and a 12‐IR LED board (850 nm), Bpy‐2D achieved a high H 2 O 2 production rate of 3.31, 4.01 and 0.48 mmol g − 1 h − 1 , respectively, with an overall production rate of 5.73 mmol g − 1 h − 1 under xenon light irradiation. The polymer retained approximately 87% of its initial activity over four consecutive cycles, establishing viologen‐based vinylene‐linked CMP as a promising class of metal‐free NIR‐active photocatalyst for sustainable H 2 O 2 production.