Verifying the Unique Charge Migration Pathway in Polymeric Homojunctions for Artificial Photosynthesis of Hydrogen Peroxide.

Artificial photosynthesis for producing high-value hydrogen peroxide (HO) using carbon nitride-based systems holds immense potential. However, understanding the charge transfer dynamics in homojunction photocatalysts remains a significant challenge owing to the limitations of current characterization techniques. Here, a polymeric CN/CN homojunction (CNHJ) is employed as a model system to probe interfacial electron transfer. Bimetallic cocatalysts serve as sensitive probes, enabling in situ tracking of the S-scheme electron transfer between CN and CN via X-ray photoelectron spectroscopy. Leveraging the unique advantages of this S-scheme, the CNHJ demonstrates substantially enhanced performance in the two-electron oxygen reduction reaction, achieving an impressive HO production rate of 8.78 mmol g h under visible light irradiation. Furthermore, the system demonstrates robust performance in continuous-flow setups, under natural sunlight, and in photocatalytic disinfection tests, highlighting its practical potential. This approach offers new insights into dynamic electron transfer mechanisms and paves the way for advancing artificial photosynthesis technologies.