Electrosynthesis of hydrogen peroxide (H₂O₂) through oxygen reduction reaction (ORR) is an environment-friendly and sustainable route for obtaining a fundamental product in the chemical industry. Co-N₄ single-atom catalysts (SAC) have sparkled attention for being highly active in both 2e^- ORR, leading to H₂O₂ and 4e^- ORR, in which H₂O is the main product. However, there is still a lack of fundamental insights into the structure-function relationship between CoN₄ and the ORR mechanism over this family of catalysts. Here, by combining theoretical simulation and experiments, we unveil that pyrrole-type CoN₄ (Co-N SAC_Dp) is mainly responsible for the 2e^- ORR, while pyridine-type CoN₄ catalyzes the 4e^- ORR. Indeed, Co-N SAC_Dp exhibits a remarkable H₂O₂ selectivity of 94% and a superb H₂O₂ yield of 2032 mg for 90 h in a flow cell, outperforming most reported catalysts in acid media. Theoretical analysis and experimental investigations confirm that Co-N SAC_Dp─with weakening O₂/HOO* interaction─boosts the H₂O₂ production.

Artificial photosynthesis is a promising strategy for efficient hydrogen peroxide production, but the poor directional charge transfer from bulk to active sites restricts the overall photocatalytic efficiency. To address this, a new process of dipole field-driven spontaneous polarization in nitrogen-rich triazole-based carbon nitride (C₃N₅) to harness photogenerated charge kinetics for hydrogen peroxide production is constructed. Here, C₃N₅ achieves a hydrogen peroxide photosynthesis rate of 3809.5 µmol g⁻¹ h⁻¹ and a 2e⁻ transfer selectivity of 92% under simulated sunlight and ultrasonic forces. This high performance is attributed to the introduction of rich nitrogen active sites of the triazole ring in C₃N₅, which brings a dipole field. This dipole field induces a spontaneous polarization field to accelerate a rapid directional electron transfer process to nitrogen active sites and therefore induces Pauling-type adsorption of oxygen through an indirect 2e⁻ transfer pathway to form hydrogen peroxide. This innovative concept using a dipole field to harness the migration and transport of photogenerated carriers provides a new route to improve photosynthesis efficiency via structural engineering.