Dual Cocatalysts Synergistically Promote Perylene Diimide Polymer Charge Transfer for Enhanced Photocatalytic Water Oxidation

Water oxidation is a critical reaction in artificial photosynthesis which is limited by a high reaction energy barrier and often requires matching cocatalysts. Dual cocatalysts Co 3 O 4 and Pt are combined with a perylene diimide (PDI) polymer, accomplishing a photocatalytic O 2 production rate of 24.4 mmol g –1 h –1 under visible light irradiation, which is a 5.4-fold enhancement compared with PDI alone. Moreover, the apparent quantum yield of the O 2 evolution reaction reaches 6.9% at 420 nm and remains 1.2% at 590 nm. The dual cocatalysts-constructed interfacial electric fields provide an anisotropic driving force for photogenerated holes to Co 3 O 4 and electrons to Pt, synergistically improving the spatial charge separation efficiency for water oxidation. Co 3 O 4 molecules serve as active sites for the water oxidation reaction to improve the utilization of photogenerated holes on the surface. This work provides a valuable demonstration of the interaction process and mechanism of cocatalysts, guiding the selection of cocatalysts for high-efficiency solar energy conversion.