An Electron Springboard in a Cascaded Acceptor D‐π‐A ₁ ‐A ₂ Photosystems for Enhanced Photocatalytic H ₂ Evolution

The photocatalytic efficiency of conjugated polymers is critically bottlenecked by the rapid recombination of photogenerated excitons. Inspired by the charge‐separation principle of Photosystem II, we report a molecular D‐π‐A 1 ‐A 2 cascade acceptor architecture featuring an electron springboard for achieving persistent, long‐range charge separation. Realized in the polymer Py‐A‐Pd‐BT (D‐π‐A 1 ‐A 2 ), this design operates through a synergistic dual mechanism: it establishes a stepwise energy gradient for directional electron relay, while simultaneously enhancing the molecular dipole (2.51 D) to generate a strong internal electric field (surface photovoltage = 54.5 mV). The dual‐driver mechanism results in markedly improved charge separation dynamics, as evidenced by near‐complete photoluminescence quenching and a threefold extension of charge carrier lifetime (3.41 ns). Consequently, the Py‐A‐Pd‐BT (D‐π‐A 1 ‐A 2 ) system enables an exceptional hydrogen evolution rate of 23.7 mmol g −1 h −1 , surpassing its D‐π‐A 1 and D‐π‐A 2 counterparts by factors of 14.8 and 8.2, respectively. This article establishes the cascaded acceptor architecture as a generalized and powerful design strategy for high‐performance polymer photocatalysts.