Structural Dissimilation of Spirobifluorene‐Based Conjugated Microporous Polymers for Efficient Overall Photoproduction of Hydrogen Peroxide

Abstract Conjugated microporous polymers offer a sustainable and metal‐free approach for photocatalytic hydrogen peroxide (H ₂ O ₂ ) synthesis directly from water and oxygen. However, the practical application remains limited by the low solar‐to‐chemical conversion (SCC) efficiency due to inefficient charge separation and transfer. To elucidate the influence of structural dissimilation on charge dynamics, two spirobifluorene‐based conjugated microporous polymer photocatalysts with different hybridized modes (sp ³ ‐SF‐AQ with a twisted sp ³ ‐hybridized geometry and sp ² ‐BF‐AQ with a planar sp ² ‐hybridized geometry) are synthesized. Photoelectrochemical analyses and theoretical calculations reveal that the near‐orthogonal and rigid structure of sp ³ ‐SF‐AQ enhances charge separation and transfer due to the increased dipole moment and the greater active‐site accessibility. This structural advantage facilitates dual pathways for oxygen reduction reaction (ORR) and water oxidation reaction (WOR), in contrast to the singular ORR pathway observed in sp ² ‐BF‐AQ. Remarkably, under the condition of pure water without a sacrificial agent, sp ³ ‐SF‐AQ exhibits a significantly higher H ₂ O ₂ production rate (6434 µmol g ⁻¹ h ⁻¹ ), approximately seven times greater than that of sp ² ‐BF‐AQ (948 µmol g ⁻¹ h ⁻¹ ), with an SCC efficiency of 1.15%. These findings underscore the critical role of structural configuration in optimizing conjugated microporous polymers for efficient photocatalytic H ₂ O ₂ production.