Terminal Group Effect of Conjugated Microporous Polymers for Photocatalytic Water‐Splitting Hydrogen Evolution

Abstract

AbstractConjugated microporous polymers (CMPs) have attracted more and more attention as active materials for photocatalytic water‐splitting hydrogen evolution, however, the correlation between terminal group and hydrogen evolution performance of CMPs is rarely studied. Herein, three triazine‐based CMPs (Ta‐CMPs) with the same polymer backbone and different terminal groups (Ta‐CMP, Ta‐CMP‐N, and Ta‐CMP‐CN) are synthesized via Suzuki–Miyaura coupling reaction using different end‐capping agents. Although the Ta‐CMPs show similar porous structure and comparable band gaps, Ta‐CMP‐CN with electron‐withdrawing terminal group exhibits the highest hydrogen evolution rate (HER) of 698 µmol g−1 h−1 under visible light, while Ta‐CMP‐N with electron‐donating terminal group exhibits the lowest HER of 99 µmol g−1 h−1. It is found that the addition of electron‐withdrawing terminal group can facilitate photoinduced charge separation, thus improving photocatalytic HER performance of the CMPs.