Rational design and synthesis of bifunctional Dibenzo[g,p]chrysene-based conjugated microporous polymers for energy storage and visible light-driven photocatalytic hydrogen evolution

Abstract

The importance of conjugated microporous polymers (CMPs) as active components in photocatalytic hydrogen evolution is growing due to its intense ultraviolet–visible (UV–vis) absorption, potent fluorescence, and high carrier transport capacity, dibenzo[g,p]chrysene shows notable photophysical and electrical features. This is because CMPs have stiff molecular structures with large π-conjugation. In this section, we describe our approach and syntheses of three types of polymers for the first time to determine the reactivity of dibenzo[g,p]chrysene (TBN)-based CMPs for photocatalytic H2 evolution and energy storage applications. Three TBN-based CMPs, TBN-TBN (D-D), TBN-TBN-TPA (A-D), and TBN-TBN-BT (D-A), were synthesized via Sonogashira–Hagihara coupling. TBN-CMP materials were used as working electrodes for energy storage applications. The TBN-TBN-BT CMP demonstrated excellent capacity retention (98.2%) over 2000 cycles and high capacitor (130 F g−1) at 0.5 A g−1, in accordance with electrochemical performance. Furthermore, the hydrogen evolution rate (HER) results are in the following order 8452, 9800, and 3060 μmol g−1h−1 for TBN-TBN, TBN-TBN-TPA, and TBN-TBN-BT CMPs, respectively. These findings suggest that using TBN as an acceptor increases the number of active sites for proton reduction, thereby boosting the rate of H2 evolution.