Calcination‐regulated Microstructures of Donor‐Acceptor Polymers towards Enhanced and Stable Photocatalytic H2O2 Production in Pure Water

Regulating molecular structure of donor‐acceptor (D‐A) polymer is a promising strategy to improve photoactivity. Herein, a porous nanorod‐like D‐A polymer is synthesized via a strategy of supramolecular chemistry combined with subsequent calcination treatment. This polymer consists of benzene rings (D) and triazine (A) that are linked by amido bond (−CONH−). −CONH− further partially cracks into cyano groups (−C≡N) (A) under calcination. The ratio of benzene to triazine could be tuned to adjust the −C≡N content by varying the calcination atmosphere. Such regulation of molecular structure could modulate the band structure of D‐A polymer and endow it with unique porous nanorod‐like morphology, leading to the achievement of two‐electron oxygen reduction and two‐electron water oxidation and the improvement of exciton splitting, O2 adsorption and activation. These merits synergistically ensure a highly efficient and stable photocatalytic H2O2 production in pure water.