Intrinsically charge-generating polymers with long-lived free carriers for efficient photon-to-hydrogen conversion
Yunzhi Wang, Partha Maity, Yinglu Jia, Baiqiao Liu, Lingyun Zhao, Yanru Li, Weiwei Li, Zhuping Fei, Martin Heeney, Suzana P. Nunes, Wan‐Lu Li, Omar F. Mohammed, Huabin Zhang
Abstract
A single organic semiconductor typically struggles with inefficient intrinsic charge generation due to large binding energy ( E B ≈ 0.5 electron volts) of Frenkel excitons, particularly in narrow-bandgap organic semiconductors that exhibit near-infrared (NIR) absorption. Here, we develop double-cable polymer–based nanoparticles (NPs), enabling single-component organic photocatalysts to achieve NIR photon absorption and generate long-lived free charges simultaneously. as -DCPIC, a double-cable polymer with donor polymer (PBDB-T) as electron-donating conjugated backbones and pendent NIR acceptor (TPDIC) as the electron-deficient side chains, offers potential for self-sustained photoelectric conversion. Consequently, as -DCPIC NPs exhibit significantly enhanced hydrogen evolution performance (11.88 mmol per hour per gram) compared to pristine PBDB-T or TPDIC NPs. Transient absorption spectroscopy elucidates the effective electron-hole separation inside as -DCPIC NPs, whereas decay kinetics monitor the long-lived free carriers (109 nanoseconds) in as -DCPIC NPs. Our findings demonstrate that double-cable polymers provide a powerful platform for establishing efficient single-component organic photocatalysts to generate long-lived reactive charges.