Local Electronic Modulation in Pillararene-Based Donor-Acceptor Conjugated Polymers for Selective Photocatalytic...

Constructing donor-acceptor (D-A) architectures is a widely adopted strategy for modulating the global band structures of photocatalytic polymers. However, it remains challenging to apply this approach to precisely fine-tune the local electronic environment of active sites to optimize elementary catalytic steps while preserving the overall conjugated network. In this work, pillararenes with electron-rich cavities are introduced into D-A conjugated polymers to construct a new material named BTzAP[5], whose reaction mechanism in photocatalytic hydrogen peroxide synthesis is systematically investigated. The electron-rich cavity of pillararene modulates adjacent imine nitrogen active sites via the extended π-conjugated system, significantly increasing their electron density, oxygen adsorption, and activation capacities. The tailored structure promotes a rapid stepwise two-electron ORR pathway of O₂ to H₂O₂, with minimal free superoxide accumulation, achieving a production rate of 4086 µmol g^-1 h^-1. This work offers a new strategy for achieving synergistic optimization of overall electronic engineering and local design of active sites in D-A type conjugated polymers.