Edged Donor–Acceptor Engineering in Conjugated Organic Polymers for Cocatalyst‐Free Photocatalytic H ₂ Evolution

ABSTRACT

Photocatalytic hydrogen (H ₂ ) production systems still heavily rely on noble metal‐based cocatalysts to lower the reaction energy barrier and capture electrons for proton reduction. But the adoption of metal during photocatalysis could significantly increase the cost and therefore hinder the further practical application. In this work, a donor (D) ‐acceptor (A) pair contained at the edge of sulfone‐based conjugated polymer chain is constructed for efficient photocatalytic hydrogen production without any noble metal cocatalysts. The conjugation extent and structural content of terminal D‐A units in the system can be successfully tuned by varying the amount of added monofunctional triphenylamine monomer. The experimental results and density functional theory calculations indicate that the construction of D‐A pair establishes an intramolecular charge transfer (ICT) path, enabling the efficient charge transfer during photocatalysis. More importantly, the carbon adjacent to the sulfone group functions as a dual‐role site that adsorbs protons while simultaneously accepting electrons as an electron‐acceptor moiety, thereby kinetically promoting proton reduction. As a result, the as‐synthesized PBA‐SO‐N ₅ exhibits high photocatalytic H ₂ rate of 19.07 mmol h ⁻¹ g ⁻¹ without cocatalysts. This strategy offers novel perspectives and feasible pathways for advancing cocatalyst‐free systems in photocatalytic H ₂ evolution.