High photocatalytic hydrogen evolution via strong built-in electric field induced by high molecular dipoles of heteroatom-annulated perylene imide supramolecule

• Published in: International journal of hydrogen energy 2023-03, Vol.48 (22), p.8071-8081
• Main Authors: Xu, Huihui, Wang, Zhiqiang, Feng, Shufan, Liu, Xinman, Gong, Xueqing, Hua, Jianli
• Format: Article
• Language: English
• Subjects: Charge transfer; Heteroatom-fused PDI supramolecule; Internal electric field; Photocatalytic H2 production
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.11.115

In recent years, PDI-based supramolecular photocatalysts have attracted significant attention. However, charge localization effects hinder the charge transfer in PDI, thereby leading to a high recombination rate and limited activity. Herein, three heteroatom bay-annulated perylene diimide supramolecule photocatalysts (N-APDI, S-APDI and Se-APDI) were developed for photocatalytic H2 evolution. Under visible-light irradiation, heteroatom-annulated PDI supramolecule display better H2 evolution rate than that of APDI without heteroatom, in which N-APDI shows the highest hydrogen production rate of 61.49 mmol g−1 h−1 and an apparent quantum yield (AQY) of 5.90% at 420 nm. The enhancement in photocatalytic activity of heteroatom-annulated PDI supramolecule can be rationalized by stronger molecular dipole, which enhance internal electric field magnitude and thus promotes the separation and migration of charge. Also, heteroatom-annulation heteroatom can act as more beneficial active site to promote HER activity. This work provides a new strategy to develop supramolecular photocatalysts. Through rational molecular structure modifications, three new perylene imide derivatives (N-APDI, S-APDI and Se-APDI) with pyrrole, thiophene and seleno have been designed and investigated for photocatalytic hydrogen production under visible-light irradiation. N-APDI shows the highest hydrogen production rate of 61.49 mmol g−1 h−1. The introduction of heteroatoms is beneficial to enhance the built-in electric field, adjust the energy level structure, and improve the photocatalytic activity. In addition, heteroatoms can act as active site for hydrogen production, further improving the photocatalytic activity of the catalyst. [Display omitted] •N, S and Se heteroatom-annulated PDIs supramolecule photocatalysts were developed.•Heteroatom-fused PDIs exhibited strong built-in electric field and reactive sites.•Heteroatom-fused PDIs effectively improved the photostability and H2 evolution rate.•N-APDI showed H2 evolution rate of 61.49 mmol g−1 h−1 and AQY of 5.90% at 420 nm.