PLNPs/SCN heterojunction composites with a green afterglow for photocatalytic hydrogen production

Abstract

Photocatalytic hydrogen production has garnered considerable attention as a latent solution to various energy challenges. Because of their distinct optical characteristics, persistent luminescence nanoparticles (PLNPs) can emit light long after illumination ends, making them highly advantageous for round-the-clock photocatalysis. However, photocatalytic activity is currently restricted owing to the low specific surface area and the high number of photogenerated electron–hole pairs. In this study, PLNP (ZnGa₅Si₅O₁₈)/sulfur-doped carbon nitride (SCN) was synthesized via a solvothermal method and calcination. Under irradiation with a xenon lamp, the resulting PLNPs/SCN (1 : 1) composite exhibited excellent photocatalytic hydrogen evolution activity, with a hydrogen evolution rate of 3963.80 μmol g⁻¹ h⁻¹, which was 15 times and 1.4 times higher than that of PLNPs (307.1 μmol g⁻¹ h⁻¹) and SCN (2800.80 μmol g⁻¹ h⁻¹), respectively. The formation of a stable type II heterojunction is responsible for the high photocatalytic activity. This heterojunction effectively suppressed the electron–hole complexation generated during photoexcitation and enhanced the carrier flexibility. In addition, the PLNPs/SCN (1 : 1) composite had a larger specific surface area than the PLNPs. The synthesis of this novel composite heterojunction under mild conditions not only provides a new strategy for preparing PLNP-based composite catalysts but also holds significant potential for enabling round-the-clock photocatalysis.