Full-Spectrum Responsive Naphthalimide/Perylene Diimide with a Giant Internal Electric Field for Photocatalytic Overall Water Splitting

Abstract

The co-assembly naphthalimide/perylene diimide (NDINH/PDINH) supramolecular photocatalysts were successfully synthesized via a rapid solution dispersion method. A giant internal electric field (IEF) in co-assembly structure was built by the larger local dipole. NDINH coated on PDINH could reduce the reflected electric field over PDINH to improve its responsive activity to ultraviolet light. Resultantly, an efficient full-spectrum photocatalytic overall water splitting activity with H₂ and O₂ evolution rate of 317.2 and 154.8 μmol g⁻¹ h⁻¹ for NDINH/PDINH together with optimized O₂ evolution rate with 2.61 mmol g⁻¹ h⁻¹ using AgNO₃ as a sacrificial reagent were achieved. Meanwhile, its solar-to-hydrogen efficiency was enhanced to 0.13 %. The enhanced photocatalytic activity was primarily attributed to the IEF between NDINH and PDINH, significantly accelerating transfer and separation of photogenerated carriers. Additionally, a direct Z-Scheme pathway of carriers contributed to a high redox potential. The strategy provided a new perspective for the design of supramolecular photocatalysts.