Coupled enhancement for mild H2O2 photosynthesis in dim light using long-afterglow photocatalysts Ni2+-Sr2MgSi2O7: Eu2+, Dy3+@Ag3PO4 core-shell heterojunction structure

The photosynthesis of H 2 O 2 from benzyl alcohol (BA) driven by hydrogen radicals (·H) is significant for industrialization. Yet, its application is constrained by narrow spectral utilization and high light intensity requirements. Herein, a novel S-type Ni 2+ -doped Sr 2 MgSi 2 O 7 : Eu 2+ , Dy 3+ @Ag 3 PO 4 (Ni 2+ -DES@APO) core-shell light mediation is developed to address limitations in BA-mediated H 2 O 2 photosynthesis. The combination of long-afterglow Sr 2 MgSi 2 O 7 : Eu 2+ , Dy 3+ (DES) and Ag 3 PO 4 (APO) can effectively enhance continuous reactions in dark environments. Optimal performance was achieved with 1 wt% DES and 5 wt% Ni 2+ doping: 374.88 mM (93,720 mM·h −1 ·g −1 ) concentration of H 2 O 2 was generated after 4 h of xenon lamp irradiation. After 2 h of continuous operation in a dim environment, the cumulative amount can reach 415.5 mM (1.41 wt% H 2 O 2 ). H 2 O 2 begins to generate at 475 nm wavelength, and the quantum efficiency reaches 1.2 % after adding Ni 2+ -DES@APO, which demonstrates broadened visible-light utilization and prolonged operation. This coupled enhancement arises from improved charge separation and surface redox processes, as well as light energy storage and photoreaction continuation in the dark via DES long-afterglow. This study presents a strategy for advancing all-weather solar-driven H 2 O 2 production by combining persistent luminescence materials with S-type heterojunction engineering. • The core-shell structure formed by DES and APO is conducive to electron transport. • The response wavelength is widened to 475 nm. • Obtaining H 2 O 2 yield of 415.5 mM by Ni 2+ -DES@APO in continuous dark environment. • The S-type mechanism was inferred through calculations and experiments. • Long-afterglow photocatalysts enable a sustained effect.